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By Lanny White - 4 Years Ago
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My stock '54 Merc quit running and I suspect the coil is the culprit. I have no fancy test equipment but my circuit tester shows power to the plus side of the coil grounded to the battery and to the minus side of the coil. I pulled the coil lead from the distributer and layed it next to the exhaust manifold and cranked the engine expecting to see plenty of fire from the lead jumping to ground on the manifold. Nothing! I tried a spare coil (condition unknown) and the results were the same. I am gettig no spark at the dist. points as well, no surprise. What am I overlooking? I have a 7 function multi-meter but am somewhat unskilled in its use.
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I hate to buy another coil if the fault s elsewhere. Any help?
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By Robs36Ford - 4 Years Ago
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You need to check that your points are connecting. When they get dirty and/or pitted they no longer connect the circuit from the coil to ground and the coil cannot charge up.
I disconnect the distributor wire from the coil and measure the resistance to the distributor body and also check across the points. The points need to be at the flat spot of the distributor cam. The resistance will be zero if they are good. If not ensure they touch. Clean them with a points file or sandpaper or if they look pitted, replace them.
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By Tedster - 4 Years Ago
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Points are kind of funny sometimes, they did go away for some good reasons. They can get a layer of skunge on them, literally overnight, and stop working.
Not a big deal for motor heads maybe but definitely the first thing to look at, check for continuity to ground with a "test light". I like the "professional" ice pick kind with alligator clip, but you can roll yer own with a length of stranded bell wire soldered to an 1157 bulb and Bob's Yer Uncle. Don't buy another ignition coil unless it is proven defective. I bet more good ignition coils get replaced than almost any other part.
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By Florida_Phil - 4 Years Ago
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I can't tell you how many times I have suspected a coil was bad only to find some other problem. I also suspect bad points. Chinese auto parts store points are often the cause. Check both ends of the coil wire too. If you are using carbon core wires, they can burn and arc.
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By Sandbird - 4 Years Ago
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The wire in the distributor that connects the points to the coil is known to break inside the insulation from the flexing caused by the continuous motion of the vacuum advance. Its insulation usually is still intact hiding the broken wire.
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By Lanny White - 4 Years Ago
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Thanks, guys. I pulled the dist. cap, crawled into the engine house (gotta luv henry's y-block dist. location) with a flashlight to check the point gap and overall condition inside the dist. housing i.e. disconnected or broken wires, grease, poor ground, etc. and I found that the points were out of adjustment. Re-gapped and replaced the condensor while I was in there. Cranked it with the cap off and saw plenty of spark. Closed it up and started the engine, runs like it should. Having a little trouble with the auto choke and need to replace the spring. Thats another day!
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By DANIEL TINDER - 4 Years Ago
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Likely explains my occasional miss I had previously blamed entirely on bad/old gas. Time to check the points.
‘Also, Sandbird’s post is a new one on me. Interesting. Will file it away.
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By JimNNN - 4 Years Ago
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"(gotta luv henry's y-block dist. location)"
Wait til you get to be my age, Lanny!  While we're on the subject, I don't know what the Mercury shop manual says, but I think the '54 Ford manual (addendum) suggests that technicians remove the entire distributor to replace standard tune up parts - points, rotor, condenser.  I haven't taken that approach yet, but as I get older, I could see how it might be easier than with the distr. on the car....unless it's frozen in place like mine currently is.
It was kind of a deal for me to remove and replace the distributor cap the other day just so I could more easily read the dist. part #. (And it still wasn't that easy to read.) Oh well, it gives me a sense of accomplishment when I'm done!
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By Lanny White - 4 Years Ago
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JimNNN, I looked at your profile and it looks like a bit further over that proverbial hill, passed 70 a few years Wrecked a few cars and fell off of a few motorcycles in my younger days, paying the price now.
Back under the hood again - stupid car and mechanic! Got it running yesterday 'cause it quit again 2 days ago. No power and can't get above idle without it snorting thru the carb and popping thru the exhaust. Re-set the timing and the mixture screws and then found that the points are toast. They were new 150 miles ago!
I may have to pull the dizzy again and do the repairs on the bench. Depends on whether or not I drop one of the points retainer screws down inside the dist. Ugh!
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By Ted - 4 Years Ago
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You might consider putting the ‘old’ condenser back in. The new crop of condensers do tend to be a shot in the dark as to how good they are. You don’t specifically mention if the car is now 12 volt or still the original 6 volt. If converted to 12 volts, you’ll need a resistor going to the coil.
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By KULTULZ - 4 Years Ago
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... but I think the '54 Ford manual (addendum) suggests that technicians remove the entire distributor to replace standard tune up parts - points, rotor, condenser. I haven't taken that approach yet, but as I get older, I could see how it might be easier than with the distr. on the car....unless it's frozen in place like mine currently is.
The main reason for that is that the LOAD-O-MATIC had to have it's advance springs tension and vacuum advance signal verified (manometer). That was more easily done on a DIST MACHINE.
This was FORD's desire to have the DIST set-up properly. Now in the world of flat-rate, I doubt this happened much. Set points with a matchbook cover and check the timing with a light and slam the hood.
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By 312YBlock - 4 Years Ago
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I agree with Ted regarding the old condenser. I installed an new “Mallory” condenser and drove to Memphis for a CTCI international. On the way down the engine started to miss then backfire. Rich Martin found someone with a back in the day condenser and it got me home to NY. I had an MSD 6A installed and said good riddance to the resistor and condenser, next step an electronic conversion kit to replace the points. 🚗
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By DryLakesRacer - 4 Years Ago
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Lanny never responded to Ted’s question on 6 or 12 volts. Burned points in 100 miles sound like 12 with no resister. In my experience the last 1/2” of the point movable arm are would be blue. If 12 volt there are many other items that require changes from the positive ground system.
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By ian57tbird - 4 Years Ago
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I've been happy with NAPA condenser, so far no problems.
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By Lanny White - 4 Years Ago
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Dry Lakes Racer, my initial post referenced a "stock" '54 Mercury which would be 6 volt positive ground. No 12 volt issues present!
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By Lanny White - 4 Years Ago
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Seems like I am chasing my tail. It starts but barely runs, engines shakes and exhaust periodically pops on driver side. Can't get it over a very ragged idle at about 800 - 1000 rpm. Obviously ignition?
New points properly gapped, new condenser, new rotor, new distributor cap, all of which went into a newly rebuilt distributor with about 300 miles on it. When changing the cap, I switched one plug wire at a time and I don't think I crossed any. However, if I did, is there a way to test each indidual plug wire following the firing order from the cap to the respective spark plug?
I have the original wire loom seperators attached to the back of the block (2 on each side) and it is very difficult to follow each wire between the firewall and the block to the open space underneath where they turn forward to the plugs. Can't shake the wires from the top, can't see the wires between the seperators, can't get my hands back there to feel and follow each wire. I tried a common circuit tester attempting to get 6 volt power to flow from one end of a wire to the other to no avail.
I don't understand the function of the spark control valve in the carb and maybe it is the culprit (carb is a newly rebuilt 1955 model 4v teapot. I also wonder if there is a possibility that the timing chain may have jumped.
Just to reiterate, the car was running well, I had just returned home from a 50 mile round trip, climbed a mild grade from the highway to the house in 2nd gear and lugged it out as I pulled ito the driveway. It bucked and snorted and quit. Acted like it ran out of fuel (which it hadn't).
Any other suggestions?
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By Sandbird - 4 Years Ago
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Start from scratch, pull the coil wire from the dist, cap and check the quality of the spark to ground. Never saw a spark control valve kill the ignition. Basically it retards the timing when the engine is put under a load.
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By Tedster - 4 Years Ago
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I'd agree with that, first pull the coil wire at the distributor cap and then check for quality of spark from coil wire terminal to ground while cranking engine over.
It should be able to jump 1/2" easily, with a fat spark. Only do this test long enough to verify. If this checks out OK, check spark through to each individual plug wire boot & terminal with a spare plug grounded to manifold. Inspect inside of distributor closely with a strong light for evidence of arcing or "carbon tracking", once it starts it is just about impossible to remedy.
Some of that "fancy" test gear mentioned isn't at all expensive these days especially when compared against the value of your time. I bought an ignition oscilloscope complete w/ all the gee-gaws and cables + manuals, for $40, I consider that a steal, it makes short work of troubleshooting and pinpointing any possible ignition problems and it's a whole lot better than guessing, or wonderin', or throwing parts at it!
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By KULTULZ - 4 Years Ago
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I also wonder if there is a possibility that the timing chain may have jumped.
Just to reiterate, the car was running well, I had just returned home from a 50 mile round trip, climbed a mild grade from the highway to the house in 2nd gear and
lugged it out as I pulled ito the driveway. It bucked and snorted and quit.
Acted like it ran out of fuel (which it hadn't).
I would verify timing. A piston-stop tool is like ten bucks.
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By Lanny White - 4 Years Ago
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More diagnosis yesterday. I had put in new H 10 plugs about 1000 miles ago and checked #1 when setting up for re-installing the dizzy. It was very badly blackened with carbon (?) buildup (baked on, beyond cleaning). I pulled the rest and replaced all with new H10s, properly gapped. I also found that the coil ignition wire terminal connection had nearly seperated from the wire and it actually broke in my hand as I was inspecting it. Cleaned it up, installed a new terminal, and reattached it. I traced out all of the plug wires to verify correct placement to their respective plugs and found #8 to be loose.
Eureka! said I... Now it will start and run. Hit the key, a few pumps of fuel, and it started. Fiddled with the auto choke linkage a little to set the fast idle and reached up to the turn the dizzy to smooth it out. In doing so, my left arm brushed against the coil which was quite hot after running only 1 1/2 to 2 minutes. I have never noticed the temperature of a running coil before and expect that it may get hotter the longer it ran, making it too hot to touch in just a few minutes. I shut the engine off and then I noticed that the exhaust manifolds were extremely hot, burning to the touch, which seemed excessive for such a short run time.
Tedster, I have already re-inspected the new dizzy cap and have verified spark at each plug. I had also previously checked spark at the coil as you suggest but following yesterday's discovery of the high temperature, I will hold off on further work until I get more feedback. Regarding diagnostic equipment, all I can remember from "back in the day" was the large Sun machines. I have no idea what might be available in today's world for a 6 volt, possitive ground, old Mercury. Any help there will be greatly appreciated. I do have a timing light, tach/dwell meter, and a vacuum gauge.
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By Tedster - 4 Years Ago
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A defective coil wire will do it. Remember it "works harder", about 8 times harder, than the plug wires in fact. Sounds like you've got a few things going on to keep you busy. Ignition coils themselves get hot, especially considering old school systems have a fixed dwell period. Slower speeds, or idle, should therefore show increased temperatures. How hot is "too hot"? Well they ordinarily dissipate about 70 watts or thereabouts. Check carefully the ohms resistance of the primary circuit, this is the total of the ignition coil primary winding, associated wiring, ignition switch, connections and ballast, if any. It's sort of like Goldilocks and the Three Bears, "too hot" or "too cold" is not what we want. The shop manual lists the specs for the ignition coil and total resistance, current, and voltages. If the primary circuit is getting too much juice for whatever reason, it will cause problems sooner or later.
"Late" or retarded ignition timing will cause the situation you describe with the exhaust manifolds. If ignition timing is way off the beam, they will even start glowing red hot in broad daylight in an astonishingly short period of time. This happens because fuel burning is not confined to the combustion chamber where intended, but is now after burning in the manifold itself.
The good news is you are making progress nailing down the issues. Get the ignition squared away, get the ignition timing squared away, and get the carburetor fuel mix squared away so the plugs aren't fouling out, and it will probably seem like a completely different engine.
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By Lanny White - 4 Years Ago
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Thanks, Tedster, for your input and encouragement. Can you recommend what type of diagostic equipment I should have in addition that that I previously mentioned?
I will go back to the car tomorrow when its cooler and see if I can get it to idle smoothly enough to set the timing and idle mixture screws. Also will check the coil temp to see if the nearly seperated ignition wire may have contributed to my sense that it was too hot. I am kind of a dunce when it comes to multi-meter operations but will attempt to check the the ohms, volts, and current at the coil. Fingers crossed!
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By Tedster - 4 Years Ago
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Honestly the best piece of diagnostic equipment you can have is the one between your ears! The thing about carburetors, is they are very sensitive to the overall state of engine tune or condition, and they will simply not respond to adjustments the way they should, if the ignition or ignition timing or valve timing are defective, or there are any vacuum leaks. This is why carburetors are often mistakenly blamed for poor performance or rough idle and other problems.
I'm not the greatest engine tuner guy in the world, so what I do, where I've had the best results is let the shop manual or general Tune Up manuals walk me through it one step at a time, in the 1,2,3 methodical order or steps laid out. They set the troubleshooting guide or "tree" the way they did for a reason. Everybody always wants a shortcut direct to "replace this part" or "tweak this screw to 1.5 turns" and everything drops into place. Start from the beginning and test test test, measure measure measure!
All of that stuff has the factory specs laid right out in the manual for you, for psi, (compression), inches of mercury, (vacuum) and volts, ohms, amps, oil pressure, fuel pump pressure, RPM, temperatures etc. I might not yet fully understand how some component or group of components is supposed to work exactly, but armed with the right manuals I can usually tell right away if it is out of range or not working as advertised.
If any specific basic test or check or voltage (or whatever) in the Tune-Up section isn't satisfactory, doesn't meet the spec, stop right there and find out why, and fix it before moving on, because it won't ever run quite right. A good, sharp tune is mostly making sure a whole bunch of operating points and adjustments meet or exceed factory specs. With vintage engines a lot of it is oftentimes simply just undoing past mistakes and getting it setup back the way it was designed & supplied according to Hoyle.
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By Lanny White - 4 Years Ago
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Tedster, I am back at it again. I checked the coil function by holding the coil wire about an inch from the exhaust manifold while cranking the engine using a remote starter switch. The spark was strong and regular, just like lightning. After leaving the ignition switch on for about 90 seconds there didn't seem to be any excess heat in the coil. I have no idea how to do further coil tests using my multi meter but the strong spark seemed to indicate that the coil is good.
I then attached the timing light, pumped the throttle a few times, cranked the engine and started, had to pump the throttle a couple more times and it died. Pumped it once more, cranked it and it started (very rough idle with occasional popping at the exhaust), fiddled with the throttle to keep it running at a higher idle (1000 rpm), still very ragged with more exhaust popping. The timing light was applied then and it indicated that the timing was correct even thought the idle speed was excessive for a really good test. The vacuum advance line had been previously disconnected and capped. I tried reducing the idle speed for a more accurate reading with the light but it refused to run well at the reduced rpm (500-600) and the tach and vacuum gauge were bouncing quite a little, with the vacuum gauge ranging from 15 to 19 inches. The engined died again as I was attempting to reduce the idle, tach was bouncing from about 400-700 rpm. The coil did not heat like it had previously done when I discovered and repaired the faulty wire connection.
I have read several other forum entries on this type of problem and some responders suggest that the timing chain may have jumped. This something beyond my realm of expertise and I don't know how to check it without actually inspecting the chain for allignment with the sprockets. Obviously valve timing relates directly to spark timing so I would assume one would look under the valve covers to see if the lifters are doing what there are supposed to at the proper time. What do I look for and how do I determine that the intake and exhaust valves are shaking hands with the distributer?
Sorry to be such a pain. The car had been recently running (until it quit) the best it had since I got it on the road in 2015. What would cause it to jump time at the chain?
The idle mixture screws are still set at 1 1/4 turns and the point gap is still correct.
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By DANIEL TINDER - 4 Years Ago
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That happened to me back in the early 70s with a poorly maintained I-6 Merc.(chain jump). Likely worn chain & sprocket was the cause (?), but while it was running ok (until it just wouldn’t start one day), the timing could have been so retarded from point wear, a back-fire might have been the ‘last straw’ (?).
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By charliemccraney - 4 Years Ago
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In the past 20 years, I have seen a jumped timing chain proposed as the problem many dozens of times. Not once can I remember it actually being the problem. Since you did get the engine running over 1000rpm and timing was good, that's not the problem since a jumped chain would directly affect the indicated timing (it would be bad by quite a bit).
Is the tachometer that you are using the tach/dwell meter and is it on the correct setting for a V8?
Earlier in the thread, you said you re-set the timing. Was it bad then? That could suggest an issue and may render a current "good" check bad.
You also said that you re-set the idle screws. If that is by the book, then that is a starting point and what your engine needs could be different. Incorrect adjustment here can prevent it from idling well or even at all. This situation would require more throttle to open the throttle blades in order to activate the primary circuit to get fuel and "idle" but at elevated speed, although it should run smoothly once the primaries are activated (you said it is very ragged).
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By Sandbird - 4 Years Ago
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You mentioned that you couldn't read 6 volts through a plug wire which makes me think you have carbon core wires. I had a '65 Galaxie that had a horrible miss after running awhile. The carbon wires were the culprit, My neighbor found it with a Sun Scope he owned. You haven't mentioned replacing your wires. If your wires were copper you shouldn't had any problem reading 6 volts through it. If you do have carbon wires with a lot of age on them I'd replace them with something metallic. You might have resistor plugs anyway. I haven't been able to buy non-resistor plugs for years. Resistor wires with resistor plugs on 6 volt ignition is a bad combination in my opinion. Just a thought.
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By Lord Gaga - 4 Years Ago
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Something is wrong with your fuel delivery system.
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By Lanny White - 4 Years Ago
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Thanks for responding, Charlie. A little background info for you so you know the history.
Restoration was completed in 2014 including a complete engine rebuild. The car has run well for several years racking up about 4,000 miles. I diagnosed some distributor problems about 250 miles ago and replaced the dizzy and changed the 1954 teapot with a newly rebuilt 1955 teapot from the Hotrod Reverand. Minor tweaking with fuel and ignition over the next 100 miles and the following 150 miles have been flawless. The best it has run since 2014.
As I previously stated, on my last outing of 50 miles, I lugged it down in 2nd gear turning into my driveway killing the engine. Thats when this mess started. I pushed the car into the garage and I could not get it to start. To reiterate, following that I pulled the distributor and replaced the condenser and relaced and gapped the points and checked the wire connections inside the dizzy. Then I cranked the engine around to TDC compression stroke (finger in #1 spark plug hole) and re-stabbed the dizzy making sure to align the rotor to #1 on the dizzy cap which I also had just replaced and then set the dizzy shaft so the points were just beginning to open so the timing would be close to correct. I cranked the engine using my remote starter, pumped the throttle at the carb linkage, and it started. However, it would not idle smoothly - engine was shaking (probably from misfiring), driver side exhast at tailpipe was popping irregularly, and I could keep it running only by manipulating the throttle trying to maintain an idle. The tach/dwell meter (properly set) shows the engine speed to range from about 400-700 as the engine shakes and exhaust pops. The vacuum gauge needle also fluctuates from about 15 -19 inches. I am unable to get it to smooth out by a minor twist of the dizzy in either direction. I currently have the curb idle adjustment screw quite advanced to keep it running at all but it continues to shake and pop. The timing light shows that timing is close but the engine speed is too fast to see clearly. The repair manual states idle speed at 475-500 rpm but the engine will not run at that rpm.
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By Hoosier Hurricane - 4 Years Ago
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You just stated that you replaced the distributor cap. Are you absolutely sure the wires are in the cap in the correct firing order? Sounds like crossed plug wires to me. The wires didn't cross themselves when the engine died, but may have become crossed when the cap was replaced.
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By Lanny White - 4 Years Ago
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Sandbird, the plug wires have about 4000 miles on them, new in 2012 and are probably the carbon core type as I am attempting to keep the car stock. All wires show good spark using a "spark checker" at the plug end of the plug wire. The reason I was trying to do a continuity test on each individual wire was to determine if I had inadverently switched the wires at the dizzy when I installed a new cap.
Hoosier Hurricane, I was very careful when installing the new cap, pulling one wire at a time and placing it in the new cap in the appropriate hole. However a boo boo may have occured and the way the engine is running would indicate switched wires. The miss seems to be prevalent on the driver side and I am unable to visually (or by feel) trace the #5, 6, 7, or 8 wires from the cap to their respective plug as the original wire seperator spacer blocks are in place at the rear of the block by the firewall. I can trace them through the first two blocks but not the third as it is too low to see or reach. If I were able to do a continuity test of those four wires from the plug to the distributor I could determine if 2 wires are crossed at the dizzy. I am able to visually trace the wires on the passenger side and they are correct.
The wires and seperator spacer blocks were attached to the back of the engine while on the engine stand prior to installing the engine into the car. Obviously that creates a problem for replacing wires in the future (without a hoist) but that is the way that it came from the factory.
Pulling a plug wire while it is running may expose a problem but probably would result in the engine just quitting. If it did continue continue to run how could check the other three? Any further help is greatly appreciated.
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By Hoosier Hurricane - 4 Years Ago
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Lanny, the continuity of the wires can be checked with an ohm meter, a feature of test multi-meters. You mention voltage reading, do you have a multi-meter? Resistance wires would check between 10,000 and 20,000 ohms typically. If you don't have a meter, I bought one at Harbor Freight for my grand daughter, I think it was about 7 dollars. It suited her needs, and would work for you to trace the wires.
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By Tedster - 4 Years Ago
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I could be mis-remembering, but it seems to me that spiral wound (and solid core) plug wires can be checked with a "beep test" continuity on a digital VOM.
Carbon core plug wires are a bit different, this won't work. So it's not as handy to check, but they will of course show resistance on the meter as Hoosier Hurricane mentions. So you could check that way, just not audibly.
Another method might be to (for example) pull the #1 plug wire boot at the plug, and install a spare spark plug and ground it. Turn the engine over both with, and without, the #1 plug wire end installed at the distributor cap. If it sparks, then that wire is installed correctly. If not...
It's sort of strange but depending on what (cylinders) plug wires are switched, it won't seem to necessarily idle too badly. Great way to get that "Lopey Cam" sound!
Sure, way down on power, backfires, but a lot of non-mechanical type people don't pay much attention. After studying some of the automotive forums for a while, maybe it isn't common to have plug wires out of firing order, but it sure isn't unusual. Of course this may not be the problem - but it's most definitely among the first things to verify.
More than one person has sold a car thinking it was unrepairable, because of this defect, and they were not happy to see the new owner drive away laughing his ass off. Oops!
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By Lanny White - 4 Years Ago
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Hey, its me again. Maybe I dummied up... When I changed coils several weeks ago I connected the ignition wire to the + terminal and the black distributor wire to the - terminal. Inasmuch as this is a positive ground application are the wires reversed on the coil???
I have attempted to check numerous condensers but I have failed to understand how to test them using my anolog multi-meter. Mostly because I don't have a good grasp of how to use the multi-meter anyway! Can someone give me very basic instructions on how to set up the meter and what to look for on the ohn scale in regard to resistance? To date I have read where the red and black leads are to be plugged in, that the ohm switch should be set in the highest position, that the dial pointer should be zeroed out, and that when touching the leads to their respective + and - positions on the condenser the pointer reading will tell me whether or not the condenser is good. The pointer swings clear to the right side of the dial on some condensers and ranges around 50 - 70 on the others. However, I do not know how to interpret the reading. Also, I have attempted to use my 7-function digital multi-meter but it baffles me more so than the anolog meter.
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By 57RancheroJim - 4 Years Ago
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We made that mistake on a friends 52 Willys that was positive ground, switched the wire around and then it ran fine. I won't tell you how long it took us to figure out our mistake LOL. I would try switching the wires..
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By Tedster - 4 Years Ago
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An (analog preferred) ohmeter can tell you a little something about whether an ignition condenser "should" work or not. But that's it. It will "charge up" and tend towards infinity. Keep in mind ignition condensers (and coils) must always be tested at normal operating temperature. Makes sense, no?
Ignition service is rough duty however, a full test requires about 500 volts DC. If your condensers in question are el-cheapo no name parts sourced from you know where (if they are anything other than OEM or similar) ignition parts I wouldn't even bother. Most people don't have test equipment to do this properly, so you're still at a guess and by golly.
The proper ignition coil polarity connection actually has nothing to do with whether the vehicle is positive or negative ground. They will work connected either way, but the spark output at the plug itself will be attenuated by about 25% if it is connected wrong. The problem is some coils have a different internal connection, coils intended for other applications. It just gives me a headache trying to think about it..
It is possible, thankfully to check for correct polarity ignition coil connections with an analog voltmeter, or you can try the "pencil test".
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By Sandbird - 4 Years Ago
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The fact that you saw strong sparks from your plug wires to ground I wouldn't focus on your coil or condenser. I remember there was a factory notice about cross firing on y-blocks discovered to be from a bad placement of the plug wires in the loom's grommets. They provided a diagram of a different placement of the wires to correct the problem. Cross firing is the result of inductive coupling from a wire beside an adjacent wire which can result in the ignition pulse going to the wrong cylinder. I've been looking for the book I saw it in but I'm having trouble finding it. I saw it in a book from a Tbird club that had a collection of factory fixes. Maybe somebody can recall and come up with diagram, meanwhile i'll keep looking
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By 312YBlock - 4 Years Ago
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At this point I would look for an ignition specialist in your area. If your not a member of a local old car club you might seek one out and check with the membership, car shows are a great place to start. Electrical, and especially ignition problems, usually are a nightmare for the average person. In your case I would seek out professional help, life’s too short. Replacing your entire ignition system might not be a bad idea and having the car converted to 12 volt a better one, oh and insist on top of the line Taylor spark plug and coil wires. I’ve been stranded do to ignition failures on more than one occasion, once due to a new China made ballast resistor, (hesitation and backfiring thru the carb) and a second time caused by a new Mallory (China made) condenser (same symptoms as resistor).
In my education from bad experience I now have a new distributor and a completely electronic ignition system, no more points, condenser or ballast resistor. Life is once again good 🚗
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By Lanny White - 4 Years Ago
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Thanks again for all of the input. I will switch the plus and minus wires on the coil while I charge the battery, too much cranking lately. I live in a very small northern Idaho town and there are no ignition specialists except for old hot rodders that may live in the area. Maybe I can locate one?
I tested for crossed wires on the driver side using my "spark tester", first checking for spark at #5 (yes) and then pulling #5 wire at the dist. cap and checking again at 5 (no). Did this for #s 6, 7, and 8 and all three checked out OK. I, too, had read about the factory seperator bleed-thru issue and will peek down behind the block in the dark if I can get it running again. Maybe there will be enough "leakage" that something will be visible.
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By Tedster - 4 Years Ago
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Regardless of how the coil is connected, it should still start, and run. See the link below that explains how this works. Be careful when cranking the engine over trying to get it to start, engine starters (and starter relays, wiring etc) are only capable of a limited duty cycle. They will be permanently damaged by extended cranking (just a few seconds) without long cool down periods. Ordinarily a well tuned engine will start in just a split second. That's how engineers were able to get away with undersized starters and relays, they are not called upon to run for long periods of time. Don't roast your starter during the troubleshooting!
Ignition Coil Polarity : https://mgaguru.com/mgtech/ignition/ig104.htm
You can also check spark (ignition coil) polarity using an analog (moving needle) volt meter. Hook up a voltmeter with the negative lead to the plug terminal and the positive lead to the block. Set the meter on the highest volt range. Crank the engine over (no need to start it), and you should see an upward swing of the voltmeter needle (don't be concerned with taking a reading). If the needle swings down off the scale, your coil is hooked up wrong. To correct it reverse coil primary leads. Do not worry about the coil markings, but make note of them for future reference.
If an ignition coil has been connected "wrong" for some time, it may even be slightly damaged as far as spark output is concerned even after the connection is swapped. They utilize an iron magnetic core. But again this is probably getting off into the weeds a bit. It is unlikely this is the cause of the Unpeasantness. The test described above though, is very quick and easy if you want to be sure.
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By Lanny White - 4 Years Ago
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Thanks again for all of the contributions to this thread.
Today I reversed the plus and minus wires at the coil, used the remote starter switch so I could manipulate the throttle and the distributor and had the engine running in 30 seconds!!! Apparently I had accidently switched them when I changed coils right after this whole mess started several weeks ago. Backed off the curb idle screw to about 600 RPM, rotated the dizzy a little until it smoothed out, adjusted the mixture screws a bit until the vacuum gauge steadied at 20 inches and tach settled down at 500 RPM.
I want to check for any vacuum leaks around the carb and intake but don't know how that is done. Help there will be appreciated. I will also recheck the dwell and the timing with a light.
Maybe I got it!! Test drive tomorrow....
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By Dobie - 4 Years Ago
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To check for vacuum leaks all you really need is a spray bottle of water. With the engine warmed up and idling spray lightly around the carb base, the intake manifold and any other places you might suspect of leaking. If you find a leak the engine RPM will pick up a little. Some guys like to use WD-40 for this or even carb cleaner. The problem with that is any overspray will be sucked into the carb, causing the RPM to increase and give you a false indication of a leak.
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