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By Melly - 4 Years Ago
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First I have a 57, Ford 312 , 57 dizzy , Holley 570 CMF carb. New plugs, was running good. Started to notice that under rpm around 3500 plus rpm. The tach started showing some goofy behavior.. would pull steady till the 3500* range motor stared a slight surging, tach. Show crazy needle movement, but rpm sounds some what steady.
When trying to find out what was happening. Check vacuum it showed 18 psi, timing 9 deg .
Look thing over but do not know what it might be. As before I need you great advice as to what going on and where, and what to do to fix issues.
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By yknot - 4 Years Ago
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I believe that you can set your initial timing at 12. should improve things.
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By Robs36Ford - 4 Years Ago
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Tach depends on dizzy for values, If dizzy is misbehaving so will tach.
Check points, condenser and advance mechanism. Also wiring to and from it.
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By paul2748 - 4 Years Ago
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Is this a sedan or a Tbird. Is it a distributor driven tach if not a TBird?
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By Melly - 4 Years Ago
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It is a fairlane, std. dizzy not tach. Drive.
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By Florida_Phil - 4 Years Ago
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Did you check to see if the ground wire is still in the distributor? This is often left out of 57 distributors when they are reassembled.
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By Lord Gaga - 4 Years Ago
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Disconnect the tach and see what happens.
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By 1960fordf350 - 4 Years Ago
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In your initial post, are you saying the engine was surging around 3500rpm, or just the tach? Stick shift or auto? You'd definetly feel a difference with a stick shift.
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By Joe-JDC - 4 Years Ago
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What happens when you try to rev past 3500 rpm? Does it smooth out and pull on up to ....what rpm? Joe-JDC
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By Melly - 4 Years Ago
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3 spd with OD, while driving in 2nd gear if I put it to floor, pulls steady til 3500 rpm then can feel surges and tach is kind of goes crazy. If you stay on it the surging continues.
I do notice that there is no ballast resistor, do knot know if it has coil with that built in or not. This is in a 1955 Ford fairlane so wiring is 1955 wired to a1957 set if that makes a difference. That I don’t know.
Going to check to see if ground wire in dizzy is there. ( it is a 1957 Ford dizzy )
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By 312YBlock - 4 Years Ago
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If you are running with a stock single point distributor the problem could be point float at 3500 RPM. I run a 55 T-Bird w/312 and a new Mallory Dual point tech drive distributor. The dual points cut the individual point open/close rate in half. If you are 12 volts and running a point distributor without a ballast resistor the points will burn out. Modern resistors made in Asia are just plain junk and will fail at some point, this happened to me, symptoms include momentary hesitation at steady speed and eventually severe backfiring. If you want to sleep nights and remain with tech drive I highly, highly recommend the Mallory Dual point distributor with an MSD 6A or 6AL ignition box. This little beauty will put only 3 volts to the points which it uses solely for timing (points will last forever just set gap and forget dwell), and it eliminates the need for a resistor as well as the condenser which is also complete junk, and give you a boost in performance that will light your fire. I put mine through an 85,000 volt epoxy filled coil with amazing results. You’ll love it!
PS a failing condenser will give same symptoms as above for the resistor.
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By 312YBlock - 4 Years Ago
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I should have looked up “dizzy” ignition before I posted as most of what I put there doesn’t apply to your situation.
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By Ted - 4 Years Ago
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The grounds both within and outside the distributor need to be rechecked. Unhooking the tachometer temporarily is a good suggestion. If that doesn’t make a difference, then this sounds like a points or condenser issue. As mentioned, point bounce could be the problem but also insure that the point gap is set to spec. The point gap being on the big side can create issues. A condenser not being tightened properly can also do the symptoms you mention.
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By Florida_Phil - 4 Years Ago
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Why run points at all? I have a 1957 distributor in my 292 with a Pertronix unit, no ballast resistor and a 1.5 ohm Pertronix coil. It's cheap enough and works perfectly. I went to this setup when I couldn't find a points and condenser set that would work more than a few days. Most auto store YBlock parts are junk.
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By DryLakesRacer - 4 Years Ago
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I agree Phil. I went thru 2 condensers before I woke up and went to the Pertronix Unit with their coil and I kept the stock ballast. They are also available for the 6 volt systems too.
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By Joe-JDC - 4 Years Ago
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Point bounce is why I asked if the engine pulled past 3500 rpm. Remove the points, bend the spring backwards a small amount, reinstall, set gap, and go for a test drive and see if the stumble goes away, or moves up the rpm scale. If it changes, a performance set of points should solve the issue. Joe-JDC
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By Melly - 4 Years Ago
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Going to try some of these suggestions hopefully this weekend. Have checking into tune up information and read so information on mechanical timing, vacuum timing, total timing. Found it to be interesting. Also found out something I did not know. That you can adjust the vacuum canister with Allen wrench through the hose port. Am I getting into this more then needed.? Any input on this subject.
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By Joe-JDC - 4 Years Ago
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Not all vacuum advance cannisters can be adjusted. Joe-JDC
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By Florida_Phil - 4 Years Ago
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I see your car has O/D. There should be an extra wire leading from the kickdown switch to the distributor. The purpose of this wire is to momentarily ground the distributor so the transmission O/D can down shift. The kickdown switch is open to the elements and can be troublesome. Temporarily remove this wire to see if it may be affecting your problem. I had all kinds of intermittent ignition trouble with mine, so I disconnected it. I have been told leaving this wire connected will blow a Pertronics unit.
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By Melly - 4 Years Ago
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first put in a pertronx igniter ll with a flame thrower ll coil. Seem to have great improve things. Tach issuse seem gone, pulls through rpms steady and power good. Only issuse is when putting pedal to floor at cursing speed pulls strong but this full throttle then cause a slight floating as it pulls rpm. I am thinking it might be a timing issue or carb. issuse. My timing is at about 10 degrees, vac. at 17. I have a 57 312ci B intake Holley street avenger 570 cmf ( do not know what jets size inside or power valve ) , 57 distributor.
At present to lead for the kick down is not connected. Have not heard the idea that connecting this lead will cause a problem. Any thoughts on this kickdown lead so I don't make a mistake connecting it?
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By Florida_Phil - 4 Years Ago
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I don't miss the kick down feature. I could fix it if I wanted to. Perhaps I will some day? If I'm going to pass, I down shift. Some people disconnect the O/D circuit by using a toggle switch. This is problematic. If you forget and leave O/D engaged in first, you could blow the sun gear. Good luck finding one. If you do, I hope your credit card isn't maxed out. The way around all this is to put the points back in and put everything back to way it was made. You could change to a 5 speed, but you would miss the cool part of having an original O/D car.
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By Melly - 4 Years Ago
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so Phil are you saying if no problem with OD kick down it might be a fine to connect the kick down wire without issuse with pertronix ?
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By Florida_Phil - 4 Years Ago
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If you are going to run a Pertronix Unit in your distributor, my personal choice is to not connect the wire from the kick down switch. The O/D kick down switch is open to the elements and it's crude by today's standards. The momentary ground signal is not healthy for a Pertronix unit. In my car it caused an intermittent miss. Since I disconnected it, I have no more problems.
Many TBird owners are sensitive to originality. To me, anything that makes the car better or safer is worthwhile. I only make modifications to my car that can be reversed just in case a future owner wishes to do so.
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