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By Florida_Phil - 6 Years Ago
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I took my TBird out for a drive today and got on it pretty good. It was running great. On the way back to the house it started missing. I thought it was running out of gas. I made it back over 5 miles and the gas gauge is reading 1/4 full. It idles fine, but has an erratic miss when you put a load on it. I checked the valve lash and everything is perfect and working. I pulled all the plugs and they are light brown as they should be. I see nothing wrong with this engine.
My 292 has a stock 1957 distributor and a 4 barrel Holley Carb. My 57 distributor is the ball bearing type with the straight vacuum advance arm. The vacuum advance is new. The distributor has a Pertronix One unit in place of points and condenser. I use a Craftsman timing light, the kind with the manual advance dial on the end. With the distributor vacuum line disconnected and the timing light set at 10 degrees, the TDC mark is right on the pointer. With the timing light set to 36 degrees and the motor reved to 4,000 RPM the centrifugal advance looks perfect. If I connect the distributor vacuum advance back up, the total advance looks to be off the charts. Is this right? If not, can I run the distributor with the vacuum advance disconnected?
I haven't found the issue with the erractic miss yet. I may have bad fuel.
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By oldcarmark - 6 Years Ago
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You can run it without the Vacuum Advance. No Idea why the Timing would be so far off with the Vacuum Can Active. Maybe Someone else has an Idea.Does the problem go away with the Vacuum disconnected?
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By Florida_Phil - 6 Years Ago
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I'll try it with the distributor vacuum line disconnected. The miss did not show up until today. It happened right I ran it up to 5,000 rpm. I checked all the pushrods (tubular) and they are OK. The valve adjustment if perfect. The plugs are not fouled. All the wires are new and connected. The engine idles perfect. I'll put some new gas in it tomorrow and see what happens. I think I may have kicked some dirt loose in the tank.
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By Florida_Phil - 6 Years Ago
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I disconnected the vacuum line to the distributor and the timing is like it should be. I has 10 degrees on the crank with about 36 degrees total. The engine idles perfectly. I backed it out of the garage and it still misses starting about 2,000 with a load. I put a vacuum gauge on it and it has about 14 inches at idle. The engine has an Isky RPM 300 camshaft. When you rev the engine the vacuum drops a little then runs up to 22 pounds and hold steady. I'll try some new gas and see what happens. I don't think the engine was a mechanical problem. It sounds like an electrical problem to me. Can a Pertronix unit cause an erratic miss? I would think it would work or it wouldn't.
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By Tedster - 6 Years Ago
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If you rev up the engine with the vacuum advance connected and check with a light, it will be "off the charts", mostly because there is no load on the engine in neutral. Vacuum advance is strictly load-based. Still, you might be surprised to learn that in stock form most V8 run 45° to 50° BTDC in steady level part throttle cruise conditions on the highway. Not a cause for concern. At least it indicates the vacuum diaphragm doesn't appear to leaking down. This is something to check.
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By Tedster - 6 Years Ago
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KULTULZ (12/13/2018)
Lot of trouble out of an IGN I. GOOGLE and you will find instances. Also, pull the cap, operate the VAC ADV with a vacuum pump and make sure the breaker plate moves and returns freely. CONDENSER source?
No condenser is used with Ignitor 1
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By Florida_Phil - 6 Years Ago
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I'm thinking I have a bad Pertronix unit. It feels like an electrical miss. I'm going to switch back to points before I get into anything major. If that doesn't fix it, I'll run a compression test on the motor and go from there. I have the vacuum advance disconnected for now.
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By charliemccraney - 6 Years Ago
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Or cap / rotor, plug wires.
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By Pete 55Tbird - 6 Years Ago
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Try running the engine at night in a dark garage and check for a light show.
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By Sandbird - 6 Years Ago
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Does your car happen to be equipped with an o/d transmission? I have seen instances where the overdrive kick down circuit would damage the Pertronix when the coil was grounded by the kick down switch. You got the right idea putting the points back in.
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By oldcarmark - 6 Years Ago
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The other Item You might look at is the Electric Tach. I believe You added One to replace the original ? Anything that might affect the Ignition Circuit is worth looking at.
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By KULTULZ - 6 Years Ago
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If returning to points corrects it, the IGN I can be affected by an electric TACH. There are service fixes @ their site. If bad, replace with IGN II.
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By 2721955meteor - 6 Years Ago
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seems odd but me and 2 others this side of the border use ford dura spark,converting the ford dist,[buying new coil and module,we all run tacks. get base parts for dist from early 302 ford dist, at wrecker. bit of a chore to wire,no issues from idea to valve float. petroxl seems to spell issues.
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By KULTULZ - 6 Years Ago
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DURASPARK II is the logical choice but is hard to hide and requires extra effort to install. PERTONIX is hidden and draws no distraction to the appearance of the engine. IGN I is old tech and has a lot of problems. They should have discontinued it when IGN II was introduced (IMO).
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By Florida_Phil - 6 Years Ago
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It was a long day, but the mystery miss is gone. Removed the Pertronix module and installed new points and condenser. No change. Disconnected the tach and O/D wires. No change. Changed coils. No change. Opened up the Holley carb and found it was full of dirt. Cleaned out the carb and installed new needles and seats along with a new power valve. Installed a new fuel filter. Plugged the vacuum advance, set the inital timing to 10 degrees . 36 degrees total on my timing light. Installed new plugs. Nothing seemed to help.
Finally I drove down to the gas station and bought 5 gallons of high test. No change at first. After a few minutes the miss went away completely. Crappy fuel.....
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By Pete 55Tbird - 6 Years Ago
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This just proves the old adage "90% of electrical problems are carburetor related" An vice versa. Pete
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By KULTULZ - 6 Years Ago
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... hmmpf ...
How long does the car sit between drives? Do you use a fuel conditioner?
How much 'crap' was in the carb? Sediment? Fuel filter?
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By Florida_Phil - 6 Years Ago
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I have had the TBird for about a year and a half. I drive this car at least once a week on short trips. The car had been sitting all summer while we rebuilt he engine. I didn't have any problems with the fuel until a few days ago. I took it out on a country road and went through the gears hard. The fuel gauge was reading low, but we had 1/4 left. As I slowed back down, I smelled gas. The car kept running, but started to miss. I thought I might have pulled off a push rod, but the engine idled OK. We made it all the way back home, but the motor wasn't happy.
The dirt in the carburetor was dark red in color. Very fine like powder. It flushed out easily with carb cleaner. I installed new needles and seats because I thought they might be hanging up which is why we smelled gas. I think the low fuel level caused some water or rust to get in the gas when it sloshed around on a power run. I have a fuel filter on this engine.
I'm going to keep the tank topped off from now on. If I have any more problems, I'm going to swap out the gas tank. Is there some gas additive that will remove water from the gas? What should I use?
I am really confused about the vacuum advance thing. I was always under the impression that vacuum advance aided the centrifugal advance, not added to it. This means the cars are running 50 degrees advance with both working. Makes no sense, but there you go. I disconnected mine and the car runs fine without it.
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By Tedster - 6 Years Ago
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I am really confused about the vacuum advance thing. I was always under the impression that vacuum advance aided the centrifugal advance, not added to it. This means the cars are running 50 degrees advance with both working. Makes no sense, but there you go. I disconnected mine and the car runs fine without it.
They do work together though completely independent systems. Vacuum advance is strictly load based, while the distributor centrifugal weights and advance mechanism is strictly RPM based. Both systems are constantly adding in or taking out timing degrees depending on whatever the specific engine load and RPM combination are at any given moment, so they complement each other.
The only time the very highest levels of timing lead like that are seen is under very specific conditions as when steady cruising on level ground. Engine load is low. Engine will run a fair bit cooler with vacuum advance among other things, there's no good reason not to utilize it on a street driven car, it will only run better. The manufacturers in fact would have left it out altogether if it wasn't a good idea.
When cruising on the highway in high gear the timing is actually quite a bit retarded relative to optimum and will run hot. Fuel mixtures are relatively lean and take longer to ignite. Lots of ignition lead is beneficial under those specific conditions. The manifold vacuum is very high at this time, conveniently. It is an ingenious system. At the time it was the only way to get more timing pulled in under those conditions.
When we see things like "36 degrees mechanical timing" remember that's a number seen only at a bit higher RPM, cruising down the highway the mechanical advance timing will be a fair bit less. Lightly loaded, part throttle, lean fuel mixtures will tolerate relatively high levels of ignition advance. This also happens to improve fuel economy, maybe 15%, something like that. It is an interesting subject and widely misunderstood, plumbing a vacuum gauge into the cabin will go a long way to helping your tuning.
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By Sandbird - 6 Years Ago
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Tedster gave a very good explanation at the beginning of this thread about the vacuum advance. I have seen engines overheat from an inoperative vacuum advance. It seems that my slow typing posted this after the fact.
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By Florida_Phil - 6 Years Ago
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Thanks for the explanation. Since it's only a vacuum line, I can try it both ways and see what happens.
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By KULTULZ - 6 Years Ago
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Fuel Additive(s) For CARBED (NON EVAP) ETHANOL USAGE-
Driving Season-
For STORAGE Season-
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By Florida_Phil - 6 Years Ago
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Thanks. I'll get some. I drove the car with and without the vacuum advance line connected. I can't tell a big difference so I put it back on. It does seem to idle better with it connected.
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By oldcarmark - 6 Years Ago
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If its on full time vacuum Port it will advance Timing at Idle which is probably why it Idles better. There's 2 different Opinions on running ported or non--ported vacuum Source. Personally I run non ported which is full time Vacuum Port. That's One reason why it will cool better at Idle because its running slightly faster turning the Water Pump. It should be hooked up.I suggested trying it disconnected to confirm it was not causing your Miss when You described how it appeared to be advancing too much when connected. High performance Engines usually run on Centrifugal Advance only due to very high lift Cams not having much Vacuum at lower RPMS. Glad You found your Problem. Sounds like You do need to clean out the Fuel Tank and Lines.Running it hard with only 1/4 Tank likely sucked up Debris from the Bottom of the Tank.
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By Florida_Phil - 6 Years Ago
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I"m going to buy a new gas tank for my 55 TBird. I see prices from $150 to $350. Who has the best tank for the money?
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By oldcarmark - 6 Years Ago
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You might check out Rock Auto. They have 2 tanks from Different Suppliers. The Spectra Tank is a popular One. That's North American Made I am pretty sure.
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By paul2748 - 6 Years Ago
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In my opinion, Sta-Bil is a bunch of crap. In many years of using an ethanol gas mixture, I never had a problem with fuel when the cars were in storage over the winter.. My son used that crap one winter, it it screwed up his carb.
KULTULZ (12/16/2018)
Fuel Additive(s) For CARBED (NON EVAP) ETHANOL USAGE- Driving Season- For STORAGE Season-
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By Florida_Phil - 6 Years Ago
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I don't think my problem was all bad gas. I think it was 64 years of crap and rust in the tank. I assumed because the gas tank looked good from the outside, it had been changed. Wrong assumption.
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By KULTULZ - 6 Years Ago
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What the problem is that gasoline and ethanol/gas blend absorb moisture from the atmosphere. So the problem started when assembly put the first gasoline in the tank. Remember DRY-GAS?
Ethanol blended gasoline is made for modern fuel injected cars with a closed emission system (EVAP). It sucks moisture readily out of the atmosphere in an open vented system.
If you found sediment in your carb fuel bowl, you have two problems, an ineffective fuel filter and corrosion and sediment in the tank. If the tank has accumulated sediment, the fuel filter blockage should stop the engine.
Something to think about-
I once worked for a station owner that ran out of fuel. Delivery was a few days off. He put a water hose into the pot to raise the gasoline level to still sell gas. Can you imagine when the fuel delivery came and dropped fuel into the pots what the gas/water ratio was until the water settled?
Also never buy fuel at a station where a delivery truck is dropping. It stirs sediment in the tanks and guess where it goes when you pump gas?
Carbed/open vented cars need some type of fuel stabilizer or you need to install a gas/water separator which will protect anything after the filter but not the tank. A nice feature on early cars was a spigot to drain water out of a gas tank.
So a blatant statement is fine against additives but you need to think what the ramifications may be. Your car and money.
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By GREENBIRD56 - 6 Years Ago
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Does your distributor still have its point plate ground? Ground for the Pertronix needs to be good - right back to the block or battery. Trying to ground through the moveable point plate - without the little braided ground strap - the resistance of the bearing/pivot can be variable and disrupt the electronics.
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By Florida_Phil - 6 Years Ago
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I have a stock 1955 glass fuel filter on my engine. The kind with the clear bowl on the bottom. I installed a new filter. My engine was clearly missing from right off idle. When driving, it would stumble all through the gears. Not enough to backfire or stall, but definitely missing. The sediment in my fuel bowls was dark brown very fine dust. It flushed out easily with carb cleaner. I assume that was rust that got past the filter.
The problem didn't materialize until I ran the tank down to 1/4 full and jumped on the motor. It's full now and the miss went away. Right after Christmas I'm putting in a new gas tank just to be cautious. I'll keep it topped off and see what happens. No more AAA tows for me. 
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By oldcarmark - 6 Years Ago
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His Distributor is like mine with the Steel Ball Bearing Advance Plate. There's 2 Brackets that attach to the Plate and Distributor Housing which I assume would be sufficient Ground as I don't think there is a Ground Wire like the later 2 Piece advance Plates?
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By KULTULZ - 6 Years Ago
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Phil,
You may want to just remove the tank, drain it and try to inspect for surface (interior) rusting. A radiator shop can clean a good tank out. If not rusted usually it is gasoline that has varnished that is the culprit.
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By Florida_Phil - 6 Years Ago
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FYI. My 1957 Ford distributor (ball bearing type) had a ground wire running from the point and condenser mounting plate to the inside wall of the distributor. I know this because I took a photo before I took it apart. This wire needs to be flexible so it does not interfere with the movement of the plate. I didn't use it when I changed to a Pertronix module. This was a mistake as the instructions say this wire is critical. I reinstalled it and it made no difference that I could see. Evidently, the ball bearings were ground enough.
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By KULTULZ - 6 Years Ago
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That GRD strap (12216) is used in all DIST as the plate mounting will not ensure a good ground. It has to be there.
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By oldcarmark - 6 Years Ago
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That Ground Wire was missing on Mine. Worked fine. I assume One end goes on Point Mounting Screw or in my case Pertronix Module. Where does it attach to the Distributor Body?
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By KULTULZ - 6 Years Ago
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By oldcarmark - 6 Years Ago
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OK Thanks for the Picture. Helpful.
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By Tedster - 6 Years Ago
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Wait, the ground wire got reinstalled and then the engine stopped missing under high power? That wouldn't surprise me as the failure mode without it being there. I think you're saying it ran fine without it and was reinstalled prior to the late unpleasantness, but one can be sure, if any part was included like that, it is necessary, or they would have left it out. Corporate accounting practices used to track costs down to the 1/4 of a cent. High voltage Ignition is funny stuff, and so is grounding.
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By Florida_Phil - 6 Years Ago
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When I initially installed my Pertronix module, I left this wire out. While chasing my engine miss problem, Pertronix told me this wire is critical. The ball bearings seem to be a good enough ground at idle. That ground is pretty shaky at speed. The wire goes from the plate to one of the clips in the side of the distributor. It's made of a flexible material.
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By Tedster - 6 Years Ago
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Huh. It seems reasonable to expect that lack of a ground in the distributor could cause the issue at high speed, under load.
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By GREENBIRD56 - 6 Years Ago
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An intermittent or variable ground will make the electronic chip in a Pertronix go nuts. Simply having resistance in the grounding - like through the point plate bearing is enough to have a low voltage problem. On the systems I have built using the Ford Duraspark II system there are old service reports concerning the grounding (black) wire - which returns from the silver box - all the way back to the distributor - and then through the dizzy base to the block. The service lit on the subject - says try a grounding wire on the distributor body. On the systems I build - I put a grounding wire on the housing - and run it to the block.
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By Tedster - 6 Years Ago
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Somebody claimed they saw 2 to 3 hp gain or somesuch on the dyno simply by running a ground strap from distributor housing to block. Not a lot, though measurable.
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By PF Arcand - 6 Years Ago
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Re 57-58 Ford Distibutors; Don't know if this has any bearing on this posting, but according to J. Mummert, most of these units were intended to be operated with about 3 degrees of intial advance & had about 34 degrees centrifical. If a modified engine has a fairly hi.po. cam & needs initial at idle set at up to 12-14 degrees, now the engine may "detonate" because the total is well above 35 degrees.. He recommends for basic retro fits 1960-64 distributors.. and notes the vacuum units are more readily available then the earlier ones..
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By KULTULZ - 6 Years Ago
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Don't know if this has any bearing on this posting, but according to J. Mummert, most of these units were intended to be operated with about 3 degrees of intial advance & had about 34 degrees centrifical. If a modified engine has a fairly hi.po. cam & needs initial at idle set at up to 12-14 degrees, now the engine may "detonate" because the total is well above 35 degrees..
It certainly does.
Depending on the DIST source (ID'd by Stamping Nos) the timing curve will most likely be inadequate for a performance engine.
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By Tedster - 6 Years Ago
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The distributor cams in the older style have different length slots that determines the amount of centrifugal advance, finding the correct OEM part would likely prove difficult as they are getting to be rare as hen's teeth. It's tedious, but the slots can be brazed up and filed to the correct length and the mechanical advance tailored that way. Using latter year distributors, there was the whole debacle with counterfeit "remanufactured" units in circulation in the last few years. I'm not sure how that ever shook out. I'm afraid to look.
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By oldcarmark - 6 Years Ago
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The Problem Distributors from Cardone were no longer available from the usual Sources (Ebay, Rock Auto, Auto Parts Suppliers) last Time I checked.
Maybe Cardone has finally owned up about them being Garbage. Some of the Repo Parts Sellers are offering Distributors but unless they are sourced from someone besides Cardone I wouldn't get my Hopes up about being useable.
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By Florida_Phil - 6 Years Ago
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FYI I have a totally stock 1957 Ford distributor in my engine that came out of a 272 station wagon with 40,000 miles on it. I also have an Isky RPM 300 cam (301333), which is pretty mild. When I degreed the cam and it was right on spec. My engine runs best at 10 degrees on the balancer. Without the vacuum line, this engine has about 36 degrees total timing according to my timing light. My engine has about 9/1 compression. I run Florida pump high test fuel. My car has a standard transmission and a 3.89 rear gear. It never detonates. My problem was bad fuel. I have not had any problems since.
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By charliemccraney - 6 Years Ago
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If it is a totally stock '57 distributor, then it should provide more than 36 degrees of total advance, closer to 45 degrees with 10 initial. It's either not stock or there is a problem with the timing light.
However, I agree, if this is the way it's been and nothing has changed and it has not been a problem, then it is not the cause.
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By Florida_Phil - 6 Years Ago
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Here is how I am determining the timing. Maybe I don't understand how this works, but it seems right to me. I have a newer Craftsman timing light, the kind where you can set the timing on the back with a dial. If I disconnect the vacuum advance line and dial in 10 degrees, at idle the TDC mark is right on the pointer. If I dial in 35-36 degrees and rev the engine to about 4000 RPM, the TDC mark is right on the pointer. This distributor is totally stock and has never been modified. I know that because I took it out of the lady's car. It has the points back in it now.
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By charliemccraney - 6 Years Ago
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The dial back timing lights can be quite inaccurate and that could be the issue. It is more than 36 degrees if it is totally stock. The mechanical advance alone should provide about 35 degrees @ 4000rpm.
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By oldcarmark - 6 Years Ago
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charliemccraney (12/20/2018)
If it is a totally stock '57 distributor, then it should provide more than 36 degrees of total advance, closer to 45 degrees with 10 initial. It's either not stock or there is a problem with the timing light. However, I agree, if this is the way it's been and nothing has changed and it has not been a problem, then it is not the cause.
Does that 36 Degrees take into account the Vacuum Advance? My understanding is total available Advance should be in the 42-44 Range. Initial + Centrifugal+ Vacuum.
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By charliemccraney - 6 Years Ago
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Total advance does not usually include vacuum advance. He says "without the vacuum line" so it sounds like the 36 is without vacuum advance.
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By Ted - 6 Years Ago
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Tedster (12/18/2018)
Somebody claimed they saw 2 to 3 hp gain or some such on the dyno simply by running a ground strap from distributor housing to block. Not a lot, though measurable.
If the engine was audibly misfiring due to a missing ground strap either to the frame or within the distributor, there will be a lot more than a 3HP gain when the ground strap is put back in place.
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By Tedster - 6 Years Ago
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No, they claimed a measurable (albeit small) increase in horsepower simply by improving the existing ground path. There weren't any defects or missing parts as under discussion here.
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By PF Arcand - 6 Years Ago
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A note with respect to the earlier distributors with the ball bearing type plate; Any current going thru the bearings to make ground with likely eventually "ruin the bearings".. How do I know? I've seen that happen with machinery when welding current runs thru bearings...
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By KULTULZ - 6 Years Ago
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A note with respect to the earlier distributors with the ball bearing type plate; Any current going thru the bearings to make ground with likely eventually "ruin the bearings".. How do I know? I've seen that happen with machinery when welding current runs thru bearings.
Paul
Now this is an informative post.
THANX!
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By Florida_Phil - 6 Years Ago
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I pulled out my gas tank today. It's full of rust. My new gas tank will be here on Monday. Wonder how much HP that will add?
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By oldcarmark - 6 Years Ago
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It won't leave You stranded which is a good thing.
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