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Buick Super 1956 engine issue


Florian
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Hi,

I am new to this forum so here’s a short introduction: my name is Florian and I live in Germany. Bought a 1956 Buick Super last November with a stock 322 nailhead engine.

It drove as it should until I did a 150 mile drive two weeks ago (city and country roads). Right at the end of the trip the engine seemed to run on 4-6 cylinders only out of nowhere, since then it is running rough but firing up immediately.

I started checking for spark and fuel, carb (Carter WCFB) is definitely working, we think not a fuel issue (cleaned the carb).

I also have spark on all (new) plugs, ignition coil is changed, BUT I am not sure about the timing:

The car has a Pertronix ignitior, with the engine off but ignition on the ignitior switches at 0 degrees BTDC.

from the sound of the engine when idling I would assume it fires a lot earlier. Centrifugal advance is working.

If I pull the spark plug wire of cylinder 1 when idling the engine’s RPM goes up. If I pull wire from cylinder 2 the engine dies. The other wires do not have a significant impact on the RPM.

Sounds like a timing issue to me.

Anybody with an idea what could be wrong?

I can’t replace the Pertronix system as I don’t have the original points, would have to order them from the US.

As I mentioned earlier, the car was running fine before (maybe a bit rich) and I did not change a thing before I had the issues.

 

Thanks a lot for your help!

 

Florian

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Until I read "pertronix" I was going to suggest: (1) compression test, and (2) cylinder leak-down test.

 

Since I read "pertronix" (1) and (2) above are now (2) and (3).

 

I won't attempt to talk you out of the electronic whizbang, but at my age, I would not ride with you unless you had at least one COMPLETE SPARE SYSTEM and the necessary tools to change it in the trunk! ;) ; Two spares would be better (I might be pertronix best salesperson ;) )

 

Hope you find the problem.

 

Jon

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Thanks Jon,

 

I am not a fan of these systems as well. The car simply came with it.

If it wouldn’t be so hard to get the original mechanical replacement parts here in Germany, I’d already be driving around with points again 😉.

 

So there is a good chance the electronic ignition system could be the problem and I have to see how I can replace it as fast as possible...

 

Thanks again!

 

Florian

 

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If he has spark, the Pertronix isn't the problem. These systems are just electronic switches instead of mechanical ones. They don't do anything to the advance curve. If timing is off, the problem is in the distributor or timing chain.

 

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22 minutes ago, avgwarhawk said:

Get rid of the Pertronix.   Some have great success and others don't concerning the Pertronix.   Install the original point system and see how she runs.    

 

Please share how, if he has spark, the Pertronix is the cause of the problem?

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21 minutes ago, joe_padavano said:

 

Please share how, if he has spark, the Pertronix is the cause of the problem?

 

 

13 minutes ago, Ben Bruce aka First Born said:

I agree with Joe!!  An electronic , Pertronix or other, either works or not.  Not on just some cylinders.

 

  Ben

 

 

Joe,

Easy check to see if it is a Pertonix issue.  Install the points system that is known as good.

 

Ben,

I have experienced(when I was turning wrenches) ignition modules do a lot of things.  Especially  when they get hot.  

 

I understand there are many who have had great success with Pertronix.  But like anything electrical these can go bad to.   My first check would be the Pertronix.  That is just me.      

Edited by avgwarhawk (see edit history)
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6 minutes ago, avgwarhawk said:

Joe,

Easy check to see if it is a Pertonix issue.  Install the points system that is known as good.

 

And that's easier than just checking for spark at the plugs how?

 

Look, we get it, you don't like Pertronix. Your personal feelings aside, it isn't the problem here. Swapping it out (and go back and re-read the OP's location and logistics problems with getting points for this car) just introduces potential new failure modes. Find the real problem FIRST, then change stuff.

 

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6 minutes ago, joe_padavano said:

 

And that's easier than just checking for spark at the plugs how?

 

Look, we get it, you don't like Pertronix. Your personal feelings aside, it isn't the problem here. Swapping it out (and go back and re-read the OP's location and logistics problems with getting points for this car) just introduces potential new failure modes. Find the real problem FIRST, then change stuff.

 

 

 

 I never said I did not like Pertronix.  You are assuming.   However, the many times I have read issues with the system not only here but other forums this is where "I" would go first.  I recommend the owner of the 56 take a look at this set up as well.   Diagnosing a vehicle with ignition issues can run from a simple vacuum leak to a lousy ground wire.   Have a nice day.    

   

 

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Joe - I think you are correct about pertronix not being the problem HERE, and I certainly understand the issue of parts for older American cars in Europe, especially during the pandemic.

 

In my original post, I suggested compression test, followed by leak-down test; BUT:

 

Electronics are so (*&^%$# unreliable (I currently have a factory unit in a 1979 Ford that about half the time will leave the distributor at full advance when the engine is shut down, the other half of the time it doesn't).

 

Today, when a customer calls with a carburetor problem, the first question is do you have pertronix? If yes, the second test is change it back to points.

 

To be fair, I don't remember many that had issues at cruise, virtually always the issues occur with idle. Taking that thought further, most of the issues occur on vehicles with generators.

 

But just because an electronic whizbang has spark part of the time doesn't mean it ALWAYS have spark!

 

With all of the "carburetor issues" I have SOLVED in the last 20 years (and I mean hundreds), with points and condensors; no offense to any one, but I consider it a waste of time to try to diagnose a problem with a pertronix installed. Fix the problem, THEN if someone wants the electronic whizbang, add it to a normally functioning engine!

 

The best excuse for the electronic conversion is Chinese-made condensers!

 

Jon.

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First of all thanks a lot for helping solving my problem!

 

If we assume the Pertronix system works as it should, what else could it be?

 

Checked a cylinder which is not firing properly (no 😎 with an endoscope but could not find major issues. I know this is not replacing compression or leak tests but I could do this at home.

 

I have definitely spark on all cylinders, but I don‘t know if the spark is strong enough to ignite the fuel every time and I don‘t know if the spark is really coming at the right point of time.

I will grab my ignition timing gun tomorrow to check if it‘s still set up correctly. Static check as I wrote shows spark triggers the coil at TDC.

 

At the end I will have to order the distributor parts from the US as it is almost impossible to find parts for a pre-1960 Buick in Europe.


I could upload a video of the engine running if it helps.

 

Florian

 

 

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Does the Pertronix have the right coil?  If the coil has the wrong internal resistance the current flow thru the Pertronix module will be too great, always use the Pertronix coil, it'll have their name on it.  You say you replaced the coil, are they both Pertronic units?

I can't understand how pulling a plug wire the RPM goes up.

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31 minutes ago, Florian said:

First of all thanks a lot for helping solving my problem!

 

If we assume the Pertronix system works as it should, what else could it be?

 

Checked a cylinder which is not firing properly (no 😎 with an endoscope but could not find major issues. I know this is not replacing compression or leak tests but I could do this at home.

 

I have definitely spark on all cylinders, but I don‘t know if the spark is strong enough to ignite the fuel every time and I don‘t know if the spark is really coming at the right point of time.

I will grab my ignition timing gun tomorrow to check if it‘s still set up correctly. Static check as I wrote shows spark triggers the coil at TDC.

 

At the end I will have to order the distributor parts from the US as it is almost impossible to find parts for a pre-1960 Buick in Europe.


I could upload a video of the engine running if it helps.

 

Florian

 

 

 

 

If the Pertronix is assumed to be working as designed...... check for any cracks in the distributor cap.  Check for any cracks in the rotor that is under the distributor cap.    Check for any vacuum leaks in and around the intake manifold.  Spark plug wires are new or old?   Nothing of note found?   Order a set of points/condenser(for testing) or  even if just for a back up.    Even I carry an extra set of points in both of my Buicks for if and when the installed points fail. 

 

     

Edited by avgwarhawk (see edit history)
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The Pertronix does not have a Pertronix coil, it is a NGK 48342 which was in the car when I bought it. I replaced it as I had one lying around from one of my other classic cars to be sure the coil is not the problem. As far as I know the Pertronix works with other coils as well, am I wrong?

 

Distributor cap, rotor and spark plug wires look new, not worn out.

I will check for vacuum leaks again, so far I did not find anything.

Starting fluid did not change the rough idle, so I don’t think it is running too lean.


I am still confused why the idle RPM is increasing (repeatable) when pulling a spark plug wire. Never had this experience with any engine.


Florian

 

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21 minutes ago, Florian said:

 


I am still confused why the idle RPM is increasing (repeatable) when pulling a spark plug wire. Never had this experience with any engine.


Florian

 

 

 

You have a  RPM meter showing the idle increasing visually when the wire is pulled or you are just going by noise of the engine?   On that cylinder where you pull the wire, can you perform a compression check?   Can you pull the valve cover on this cylinder head to assure all the valves are moving?  

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I was just going by the noise of the engine but I also have a RPM meter, it was really obvious to hear.

Valves are moving, pulled both covers as I checked all valves to open properly.

I have to get a compression tester, that is something which is missing in my tools...

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27 minutes ago, Florian said:

I was just going by the noise of the engine but I also have a RPM meter, it was really obvious to hear.

Valves are moving, pulled both covers as I checked all valves to open properly.

I have to get a compression tester, that is something which is missing in my tools...

 

 

Use your RPM meter to assure what you are hearing.  The noise may just be throwing your off unnecessarily.   Post a video is you are able. 

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First check the distributor grounding. I do not recall which style distributor the 1956 uses, but either will have a ground wire for the breaker plate to deal with the motion of the vacuum advance. It is a special flexible wire interwoven with copper and spring steel to deal with the constant flexing. It is still needed with the Pertronix.

 

Florian has stated that the points would have to be bought and shipped from the US. Let's not make this about the pros and cons of Pertronix. Removing it for testing would be a good first step if it were practical to do so. It could easily be put back after the car is fixed. Electronic ignition of any brand can trigger improperly.

 

Look inside and outside the distributor cap for cracks or carbon tracks. It might be trying to fire 2 cylinders at once. Make sure the carbon button in the cap is present and can touch the rotor. Ohm test the plug wires. I believe 1956 Buick still had the plug wires under a metal shield. Defective ignition parts can raise the voltage and cause cross firing or arcing under the shield. Temporarily bypassing them with some new cheap wires is the easiest way to eliminate them as a cause.

 

When pulling a spark plug wire increases RPM, it is most likely a mechanical problem, I have seen it when bad fuel has caused valves to stick and bend a pushrod or several. If an exhaust valve will not open, the engine will behave this way. I see this has been checked.

 

Compression and leakdown tests should be the next step.

 

 

Edited by Bloo (see edit history)
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You said engine dies when you pull off # 2 wire? but speeds up if 1 is pulled off. If it quits right away with a wire pulled off it must be killing the pertronix. The only other thing would be a cross-fire between 1 and 2. They are adjacent on the cap.

 

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I am not an electronic ignition fan, but I am a retired electronics technician with a lot of varied experiences.....  That said I will agree with what has been said above. Any electronic ignition system can have erratic triggering, IE: Erratic ignition timing. Pertronix ignition systems have documented issues with voltage, coils and grounding. That does not mean they are bad, it just means things need to be right. As the engine was running fine and failed suddenly, I would look at things that could have suddenly changed. Bloo pointed out several first suspects. Next check the power wiring to the Ignition system. I would actually bypass the ignition power with a wire from the battery to the Pertronix module for testing. Check grounds, grounds and more grounds! The breaker plate ground wire is extremely important! Again, after checking the breaker plate ground wire in the distributor I would run a test wire from battery negative to the distributor and clamp it in place for testing.  Also, I just googled the timing specs for a 56 322 and it said 5 deg Before TDC. You said it was firing at 0. You may want to rock the distributor a bit and see what happens or with the timing light set it right and see. It is possible that if the clamp bolt was not tight the distributor could have turned in the block.

OK, I have said enough. Just take it one step at a time and ASSUME NOTHING!!!!!!  Pertronix has detailed information on their web site. Go check it out and make sure all is correct.

Good Luck and keep us posted!!

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Thanks a lot to all of you who helped me figuring out what to do next. Your effort is highly appreciated!

 

1. I will check the distributor again tomorrow (as we have a public holiday today and no rough engine running accepted in our neighborhood) which was clamped down right (check copper wire which is present but may have a bad connection, bypass ignition power, add an additional ground wire), set timing with timing gun (not only with voltmeter with ignition on rotating the engine by hand), check for cross-fire while measuring the rpm at idle, ohm out and change the spark plug wires to the set of my 68 Mustang 289cui engine

2. Do a compression and endoscope test (not only but primarily on cylinder 1) on Saturday

3. Wait for a new Pertronix to arrive beginning of next week which was on stock here in Germany to make sure the module is fine

4. Start crying when nothing helps 😉

 

Hope I did not forget something and my plan makes sense...

 

Thanks again!

 

Florian

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19 hours ago, Florian said:

The Pertronix does not have a Pertronix coil, it is a NGK 48342 which was in the car when I bought it. I replaced it as I had one lying around from one of my other classic cars to be sure the coil is not the problem. As far as I know the Pertronix works with other coils as well, am I wrong?

 

Distributor cap, rotor and spark plug wires look new, not worn out.

I will check for vacuum leaks again, so far I did not find anything.

Starting fluid did not change the rough idle, so I don’t think it is running too lean.


I am still confused why the idle RPM is increasing (repeatable) when pulling a spark plug wire. Never had this experience with any engine.


Florian

 

No, the Pertronix will want a 1.5ohm coil.  Did you bypass the ballast resistor? the Pertronix wants full 12v.  How did you deal with the wire coming from the starter solenoid? yellow, I believe, how did the Pertronix get connected so it see voltage at 'Start' on the ignition switch?

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In the manual I found online it says „should read 1.5 ohms or greater for 8 cylinder engines and 3.0 ohms or greater for 4 and 6 cylinder engines“

the NGK coil has 2.8 ohms.

 

When I got the car (which was running) the NGK 12v coil and the Pertronix were both connected to the ballast resistor, meaning only 8v did come from the ignition. The hot wire from the starter was not installed.

I checked the internet right after I got the car as I felt this could be wrong and there were different opinions if this setup works or not. At least it worked in my car. So I left it that way.

 

After the engine started running rough I bypassed the ballast resistor and connected both coil and Pertronix directly to 12v ignition power to see if it would make any difference, but it didn‘t, it was still shaking while idling.

 

Even if it ran without sufficient volts for a while this should not have destroyed the module, right?

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I am not sure how Pertronix designed their system, but I would not expect low voltage to destroy the module. I have heard of systems hooked up like you describe that had problems until the ballast resistor was bypassed. This should be clearly addressed in the Pertronix instructions. One good thing is that by ordering a new Pertronix module you will get the instructions AND have a good or spare module!!!

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So, you have the wrong coil, the resistance is too great.  Get a Pertronix coil with 1.5ohms.

How does the Pertronix see voltage at 'Start'?  The original ignition switch will not give power to the coil at 'Start', the power would come from a set of contacts on the starter solenoid (it was done this way to bypass the ballast resistor so the ignition would see a full 12vdc).  You say the wire from the starter is not connected, so how is it getting voltage to start?  I bring this up because problems have a way of being interconnected, I realize it may seem pointless because the car will start.  It may be that the ignition switch has been replaced with a GM HEI ignition switch.

I'll bet you are using a digital volt-ohm meter to read voltage, they'll mislead you.  Find an old analog meter, the kind with a needle, they'll give you the actual voltage.

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Yes, I read it wrong, I read the Pertronix instructions from their site and thought it said maximum for V-8 motors is 1.5, I just checked and it says minimum 1.5.  I'd still get a Pertronix coil.

I went thru the same thing on a '67 Caprice, I thought any old coil would do and it worked for about 6 months to leave the people stranded.  If you use Pertronix ignition then get Pertronix parts, you use Delco, then get Delco etc

 
 
 
 
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25 minutes ago, ojh said:

Yes, I read it wrong, I read the Pertronix instructions from their site and thought it said maximum for V-8 motors is 1.5, I just checked and it says minimum 1.5.  I'd still get a Pertronix coil.

I went thru the same thing on a '67 Caprice, I thought any old coil would do and it worked for about 6 months to leave the people stranded.  If you use Pertronix ignition then get Pertronix parts, you use Delco, then get Delco etc

 
 
 
 


I would not say it‘s the wrong coil, but you are right, it is not the recommended coil. But I‘ve seen various (European) cars with a stock coil and a Pertronix. But in the long run I will go back to points or get a Pertronix coil.

 

And yes, the wiring was definitely not correct. I bypassed both ground and 12v with a cable directly from the battery today, unfortunately no change. Maybe too long operation with low voltage has destroyed the Pertronix, we’ll see when the new one arrives. I will bypass the ballast resistor and connect the Pertronix to ignition power from now on as shown in the manual.

 

It’s still the stock ignition switch. So I would reinstall the missing wire from the starter solenoid to make sure the Pertronix also gets 12v when cranking, even though the car was running fine without it. Does the car not start with points when the bypass wire is not installed?

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  • 2 weeks later...
On 5/12/2021 at 11:24 AM, joe_padavano said:

If he has spark, the Pertronix isn't the problem.

I invite you to read all the problems Pertronix have on corvaircennter.com/phorum.  Most all are "it runs, just not correctly anymore".  90% of the failures are not complete failures anymore. Those Pertronix from 20 years ago seem to last longer. 😉

 

On 5/12/2021 at 12:26 PM, Ben Bruce aka First Born said:

I agree with Joe!!  An electronic , Pertronix or other, either works or not.  Not on just some cylinders.

 

Ha! Like you never saw intermittents in electronics?🤣

 

Here is just ONE recent discussion:

 

http://corvaircenter.com/phorum/read.php?1,1116854,page=1

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Hi all,

 

sorry that he update took a while...

 

- I changed the Pertronix module, with the new module it would barely start (it at least changed something)

- set the timing, did not improve, still sounded like it was too advanced until it starts ticking

- did the compression test, all cylinders around 130 PSI when engine is cold, except cylinder 7 which was zero

- endoscoped the cylinder and found a stuck open intake valve, which is bent and touches the piston (shiny mark on piston and valve)

- took of valve cover, rocker arm is not under tension when valve should be closed

 

I don‘t know if this explains the behavior but I need to take off the head and get this valve repaired, will probably pull the engine to get it rebuilt and fix some other minor issues (leaking rear main seal). So the car will be out for the summer season...

 

Thanks to all of you who did a great job helping me!

 

Florian

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6 hours ago, Florian said:

- did the compression test, all cylinders around 130 PSI when engine is cold, except cylinder 7 which was zero

- endoscoped the cylinder and found a stuck open intake valve, which is bent and touches the piston (shiny mark on piston and valve)

- took of valve cover, rocker arm is not under tension when valve should be closed

 

So it was NOT the fault of the Pertronix. Imagine that... 🙄

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5 hours ago, joe_padavano said:

So it was NOT the fault of the Pertronix.

Never said it was, just that a bad Pertronix IS a possibility. You stated if the engine ran at all the Pertornix was verified good. The only way I know to troubleshoot a Pertronix is by substitution.  I'm sure an ignition scope would help narrow down if the problem was electrical, but not many hobbyistssts have one. Ed and Padgett excluded!😆

 

Looks like Jon (Carbking) wins the troubleshooting race with the first post to say check compression. 👍

 

Go with the tools you have to eliminate suspects. No ignition scope? Then try your other tools. I should write that down in my garage!😉

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4 minutes ago, Frank DuVal said:

Never said it was, just that a bad Pertronix IS a possibility. You stated if the engine ran at all the Pertornix was verified good. The only way I know to troubleshoot a Pertronix is by substitution.  I'm sure an ignition scope would help narrow down if the problem was electrical, but not many hobbyistssts have one. Ed and Padgett excluded!

 

That wasn't directed at you, Frank. 😉

 

Now, having said all this, I recently read a thread on another forum where an engine with a Pertronix was misfiring on one cylinder. Turns out that version of the Pertronix for Delco distributors uses a ring bolted under the rotor with eight individual magnets to trigger the spark. One of the eight had fallen out of the ring.

 

48104275d1497699093-lost-one-zylinder-pe

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