# It just will not run right



## 646904GTO (Feb 10, 2008)

66 Tripower, fresh 10 years ago but never started. Fired it up and broke the cam in. only runs on 2,4,6 and 7. Other cylinders getting spark but appear to over fuel. (plugs wet, pyro temps 150 degrees) no change with plug wire pulled. compression test lowest 195, highest 225, cold cranked. intake vacuum 10"hg. replace intake and went to single carb. Same results. replaced distributer, cap, rotor, wires. verified spark plugs at .035. Dwell at 30. swapped out coil. good fuel pressure and needle and seat holds it. Checked valve lash (hydraulic), correct.verified spark at plugs too. Basically all the parts including the tripower and carbs, dist., carb, wires, coil, etc. are all new (not to say something new isn't bad)
wouldn't think the timing gears could be off since it actually runs very strong with only 4 holes firing good. I guess the next step, even though it is fresh is to tear it down and start over. Suggestions?


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## Lemans guy (Oct 14, 2014)

First re-verify *firing order*, check and be sure. 

Next, compression on left side 1,3,5,7 must be right and rockers and springs must be working right. Could the push rods or lifters be hanging up?

Remove the valve covers and plug the rockers with those little wire things all the auto parts houses sell so the oil doesn't shoot everywhere, and watch the rocker arm assembly when it is running....see if rockers are moving as suppossed to or hanging up...

A leakdown test on each cylinder might be a good idea as well, as a bad head gasket or* intake manifold gasket put in the wrong way on that side could be causing the * the mixture to be too lean and won't fire.

Smoke test can find that,....but if you have had that intake on and off with the tri-power that would be a place to suspect.....

*Bad left intake gasket or head gasket*

Hang in there you will get it!:nerd::nerd::nerd::nerd:


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## Lemans guy (Oct 14, 2014)

PS 64 a no firing condition, if from a lean mixture as I described will make the plugs wet as the fuel does not fire....it seems counterintuitive that a lean condition causes wet plugs, 

*but just possibly your lean condition causes no fire at all and all the unburned fuel remains in the left bank of cylinders..so check those gaskets*, if you have lived a good life it may be the intake gasket!


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## PontiacJim (Dec 29, 2012)

Hmmm. New one on me. 

Do you have a good ground between your frame/engine and engine/body? Could be as simple as poor grounding affecting the plugs.

Noticed your vacuum is not all that good at 10", but may be because only one side is firing. I would be looking for a vacuum leak on that side - to include the hose going to your power brake booster if you have one. Spray a little carb cleaner around gaskets/carb to see if the engine speeds up.

Read on one post that the problem was a collapsed exhaust pipe on the side that was having all the issues. The stock exhaust manifolds had an exhaust "butterfly" to route exhaust gas under the intake and as the engine warmed, a bi-metal spring would unwind and the butterfly would go to its full open position. If a car sits, these things will freeze up closed on you. So check for this as well as put your hand on the tail pipes to see if you fee the same amount of flow.

I would also put in a new set of plugs as once they get wet, even though you clean 'em, you can have problems.

As suggested by *Lg*, pull the rocker arm cover on the bad side. Check the valves. You might have them too tight and they are not closing. I know that sometimes people are given Chevy lifters which will not work in a Pontiac - oil band in the wrong place and you won't get any oil to the rocker arms. I don't know if it would cause any issues with keeping the valves slightly open once they pump up after they are running. 

It is possible that the head was milled on that one side and the rocker arm geometry is now off - pushrods too long and keeping your valves open slightly.

Distributor- what type? Points or electronic? Rebuilt or original? If original points, bushings could be worn, condensor weak/bad, poorly grounded, vacuum advance can not working correctly or sticking. Are you running the engine with the vacuum line to the vacuum advance unplugged? Try that to see if it does anything.

Try a few of these suggestions and then let us know. Just seems odd that it affects only 1 bank.


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## 646904GTO (Feb 10, 2008)

thanks guys. It affects both banks. 1,3,5 and 8 don't fire. When I first looked at the valve train it had store bought washers under poly locks with stock studs(lol). I pulled all of them, checked that valve height was all the same on each head and installed stock nuts minus the washers. I watched each one go to zero(with the push rod cover off) and as I went to zero lash they depressed the lifter and locked at 3/4 turn. So all good there. As far as the distributer the stock rebuilt numbers one is points and perfect BUT, I swapped it out with one i have that is from one of my race cars. It is only mechanically curved and has points. Also changed the cap, rotor and wires to be sure. As fas as plugs go I put the plugs from the non-firing cylinders into the firing cylinders and it runs the same. I also replaced the intake gaskets along with installing a 1967 square bore iron pontiac intake plus a AFB that came off my '73 Challenger when I put it back to Stock. The Challenger ran perfect with it. So I guess what I am saying is ANYTHING that was a variable or suspect I replaced with proven parts and get the same result. Only thing that caught my attention was when I was installing the intake it was difficult at first to get the bolts to align because I think the block may have been decked a little. I have a fresh '67 XH that was decked to zero and it has its own iron intake and NOTHING else fits it, so I am starting to lean that way. When I pulled the tri-power the gaskets were wet at the bottom, but that can come from disassembling too. I think the next thing to do is pull the intake and set it on minus the gasket and measure the clearance across the gasket area. in answer to valves being open there is no backfire or exhaust pop to indicate sticking or partially open valves. Your right Jim, I will get it, I've been building Pontiacs since 1978 so I feel I know them.


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## 64GTOConvertible (Aug 28, 2016)

Interesting that with one exception the cyls that don't fire are together in the firing order. But since you swapped dizzys I doubt that has anything to do with anything. Have you verified spark at each of these cylinders?


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## Lemans guy (Oct 14, 2014)

Sorry about that I read 135 and put the 8 in myself, I think you are on the right track. When you changed Dist did you change the cap and rotor as well? It can be done either way...if you were using the same ones I would suspect a cracked Dist cap, which can give that odd failure to fire.

I don't know if you have access to a scope, or even a spark KV tester, cylinders can spark, but the spark is weak and won't fire the cylinder...if you do it by visual alone you see spark, but that spark is not under compression where it needs more kv to fire, ......

It is an odd set, crossfiring wires, weak KV, cracked Dist cap...if the problem is ignition. Fuel problem can be what you are searching for on the engine, if the deck cut lets air in to screw up the fuel air mixture....

Anyway, pulling for you sure you will get it!


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## PontiacJim (Dec 29, 2012)

If you had the deck zero milled (about .020") and the heads trimmed a bit, could be some misalignment with the intake - so your intake may indeed not be sitting squarely at the base and is why the gaskets were wet with gas on the bottom. The intake bolts should fit fairly easily. So you most likely need to have the intake cut down since you won't be pulling the heads and milling them. Could be a gasket matching problem or not seating correctly.

If you have "stock studs," assume you are talking about press-in studs. Using stock nuts, and not the polylocks, they need to be torqued in place. You cannot use the stock nuts to zero lash the valvetrain - that's where polylocks are used. The stock nuts will eventually back off.

Second, with the deck zero milled and the heads most likely milled, your pushrods are most likely too long and again, may be holding open the valves. I would confirm the pushrod length using a pushrod checking tool. All the info on how to check it is here and you can get the one you need: http://www.compcams.com/catalog/COMP2012/pdf/COMP_Catalog_2012_292-311.pdf

"I also replaced the intake gaskets along with installing a 1967 square bore iron pontiac intake plus a AFB"

You could have a mismatch between the carb/intake. Some of the original AFB's were only about 500CFM's and smaller in size. The later AFB's may have a larger base and could be hanging over exposing vacuum ports or even the throttle blades. If you have the 750 CFM, it has the larger secondaries which may not open on the smaller Pontiac AFB. Did you verify the fit and correct matching gasket? Could be sucking air.

Hang in there and keep checking things. Gotta eventually figure it out. :thumbsup:


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## 646904GTO (Feb 10, 2008)

64GTOConvertible said:


> Interesting that with one exception the cyls that don't fire are together in the firing order. But since you swapped dizzys I doubt that has anything to do with anything. Have you verified spark at each of these cylinders?


Yes and put the non-firing plugs into the hot cylinders...same result


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## 646904GTO (Feb 10, 2008)

PontiacJim said:


> If you had the deck zero milled (about .020") and the heads trimmed a bit, could be some misalignment with the intake - so your intake may indeed not be sitting squarely at the base and is why the gaskets were wet with gas on the bottom. The intake bolts should fit fairly easily. So you most likely need to have the intake cut down since you won't be pulling the heads and milling them. Could be a gasket matching problem or not seating correctly.
> 
> If you have "stock studs," assume you are talking about press-in studs. Using stock nuts, and not the polylocks, they need to be torqued in place. You cannot use the stock nuts to zero lash the valvetrain - that's where polylocks are used. The stock nuts will eventually back off.
> 
> ...


What i meant to say was I used stock Pontiac rocker nuts and turned them down to zero lash. Then each one went 3/4-1 turn to torque so the pushrods and train should be correct.I have a length checker since I built my roller for my 64.
Carb and intake match plus it ran the same with the tri-power set up, same dead holes, etc. I have eliminated all the variables items it seems. I think I need to compare intake, head angles.


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## Sixty7GTO (May 4, 2017)

Did you replace the cam when you rebuilt the engine? I've seen a cam in the wrong box. Check your cam lobes with the firing order. Make sure your valves are opening at the correct time. Was the cam degreed at the time of installation and checked with a degree wheel? I know there are Ford cams that actually change the firing order. Don't know if any of the aftermarket companies did that with Pontiac, but anything is possible.


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## 64GTOConvertible (Aug 28, 2016)

I just discovered there are cams that change the firing order on this site last week! My initial thought? The poor schmuck that gets the engine next is gonna have a bitch of a time changing wires...

Seriously though, this was my first thought here. You've got compression, you got spark, you got fuel. It should run. Seems to me firing order is the most likely culprit now.


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## PontiacJim (Dec 29, 2012)

First, the stupid question. You did put the firing order Counter Clock Wise? Pontiac distributors go CCW.

OK, here is a wild guess. Did you use a degree wheel to verify the timing marks/cam? It might be possible the cam is out of phase or the timing marks were set 180 degrees out. Have you verified that No1 piston is at TDC? Found this post which has a similar ring to your situation: https://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=206883&page=1


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## 646904GTO (Feb 10, 2008)

Sixty7GTO said:


> Did you replace the cam when you rebuilt the engine? I've seen a cam in the wrong box. Check your cam lobes with the firing order. Make sure your valves are opening at the correct time. Was the cam degreed at the time of installation and checked with a degree wheel? I know there are Ford cams that actually change the firing order. Don't know if any of the aftermarket companies did that with Pontiac, but anything is possible.


I did not build the engine. So no I did not install the cam and have no idea what it is but knowing the owner of the car I am assuming it is a '66 Tri-power cam.


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## 646904GTO (Feb 10, 2008)

64GTOConvertible said:


> I just discovered there are cams that change the firing order on this site last week! My initial thought? The poor schmuck that gets the engine next is gonna have a bitch of a time changing wires...
> 
> Seriously though, this was my first thought here. You've got compression, you got spark, you got fuel. It should run. Seems to me firing order is the most likely culprit now.


Yes i do know of the different firing order. The Ford 289/302 had a firing order different than the 351W engine BUT at some time the 302 changed to the 351W order. I found this out when I built my 302 with a SVO cam last winter for my '55 Tbird road racer. I agree it has to be the wrong firing order OR the Cam is miss ground.


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## 646904GTO (Feb 10, 2008)

PontiacJim said:


> First, the stupid question. You did put the firing order Counter Clock Wise? Pontiac distributors go CCW.
> 
> OK, here is a wild guess. Did you use a degree wheel to verify the timing marks/cam? It might be possible the cam is out of phase or the timing marks were set 180 degrees out. Have you verified that No1 piston is at TDC? Found this post which has a similar ring to your situation: https://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=206883&page=1


I pulled the timing cover the other night and found it had a 3-way crank gear that was set at 5 degree advance. Knowing this wasn't causing the problem but was a variable I replaced it with a straight up set...just in case. Of course I know they turn CCW but a good question nonetheless Jim. firing cylinders = cylinder number. non firing cylinder =x
x 2
x 4
x 6
7 x

is there some pattern to this?
I going over to read that post about the bird now.


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## 646904GTO (Feb 10, 2008)

I read it and doesn't seem to pertain to this issue. I checked the static timing of the gear set with the cover off. Yes Pontiac timing set up on cylinder 1 is both gears at 12 O'clock. Chevy, dodge are 12 and 6. It has to be something simple I just know it.


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## Lemans guy (Oct 14, 2014)

I still think firing order is a suspect, or a lean condition because the gaskets or decking of the head, block, Intake etc,

the odd cylinders not firing, 2,4,6. & 7.....is the unusual event

you checked the timing chain and cam and changed the Dist cap and rotor,...

so what else can cause that? First is the simple thing which you checked..the plug wires in the proper order absolutely verified....

since three cylinders do not fire on the left side can those wires be shorting on a plug wire tower? shorting to ground? maybe causing the #7 to fail as well?

any arcing on those towers? watch in the dark...also check plug wires with an ohm meter,..even if new.

I use my Oscillisscope to look at the plug wires while running to see weak spark, but you can check it with a KV tester,..even a spark checker, a few bucks at auto parts store,...you are looking not for the presence of spark only but the strength of the spark, that it takes to jump the gap.

I apologize because I know you know all this, but just for the discussion, spark under compression has to be stronger than an observed spark outside the engine. A spark to weak to jump the gap under 150 PSI will jump the gap when you observe it outside,...unless you use the approprite scope or spark checker.

the spark checker is adjustable, so screww it out until it is at 40 or 35 and test each cylinder then...

any difference? change the plug wires and or look for a short where those wires are shorting to ground.....

if not there then you are back to the possible Vac leak from lean condition..

a warped intake manifold, or bad gaskets or decking,....:nerd::nerd:


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## 646904GTO (Feb 10, 2008)

i have done all the spark and wire testing. 1,3,5,and 8 do not fire. I am using a different distributer, cap, rotor, wires. run engine then swap plugs from firing cylinders into non firing cylinders and it runs the same. 1,3,5,8 make very little heat. 
Here is something to consider Lemans Guy...at 2400 rpm it will make a little heat at the exhaust port(150degrees) on the non firing holes and manifold vacuum is about 16-17 Ihg. start to drop the rpm and although I am closing the throttle the vacuum drops to 7 and unless I close the air door and start fluttering the throttle it will die yet it is just pouring fuel out. It is not atomizing the fuel mixture in the intake. Has no measurable manifold vacuum during crank. I wish I had an old time oscilloscope. I think when I get back at it I am going to put in a used stock camshaft I have and see what I get. If it doesn't fix it, it will just have to come out, apart and be built from the ground up so I know it is correct since I didn't build it in the first place.


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## Lemans guy (Oct 14, 2014)

I think you are on the right track as the bad cylinders 1,3,5 & 8 (sorry I kept getting those wrong).....are definetly a matter of...

1) weak or no spark......This you have thourghly checked with dizzy and wires and plugs...

2) poor compression "at the firing moment", .......a compression test will not show that up, as it just checks that the cylinder "has" compression after 4 turns,...but not "when" that compression occurs. you can look at the tops of rockers etc, but just a slight deviation can cause the valves to not seal,...then cylinders does not fire and vac is low...

3) lean mixture caused by bad gaskets or engine, or head decking. this would be the fuel/air problem where too much un-metered air leans out the mixture and causes those cylinders sucking air not to fire, they then produce the wet gas condition.

So I think changing out the cam with a known cam may fix it, maybe while in there you will discover something else ....lifters that are somehow malfunctioning or as PJ said push-rods not right.

I do think you are getting there maybe the builder was trying to make a tri-power and only had a cam from an old cushman that he stuck in there, it has 3 wheels...that is tri-power, Right?:nerd::nerd:

we are pulling for you.hang in there !


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## PontiacJim (Dec 29, 2012)

This is a real stumper. You seem to have experience, so I know you know what you are doing. But here are a few things to throw out at you.

At this point, it could be anything.

I was using the timing mark on the crank pulley to set my timing. Called the cam manufacturer and told him my problem, engine heat soared. I mean my water temp would soar and I watched it climb like a rocket on the gauge and would shut it down when it began to hit 220 which was only after a few minutes. He said sounded like the timing was retarded and to advance it. So I did. Engine then ran great and the high temp went away. Checked the timing mark at the balancer, and it was way off. What I had done was used the balancer that came with the 1972 engine. What I did not know at the time was that it was actually a later 1976ish solid hub which was smaller than the 1972 balancer and of course, no outer ring. So the timing pointer was way off in relationship to the timing line on the balancer - because it was a whole lot smaller in diameter. Someone prior to me had done some swapping. It ran fine with it, but I could not use it to time the engine with a timing light - had to do it by ear and use the "pinging" method.

That said, do you know that the balancer/timing cover are correctly matched? Are you sure the outer inertia ring has not slipped due to age/deterioration? There are 2 different sizes of balancers used on the 65 and up engines.

Have you used a TDC stop to verify top dead center of the No. 1 piston as opposed to using the rocker arm closing method? I might find TDC with the stop and then see where your balancer line lines up on the timing cover scale just to verify all is good.

If that checks out, I would then rotate the engine by hand to put each cylinder into its correct firing order and note that the rockers are both closed and that the timing mark shows that the distributor should be firing. Then I would have the coil wire and cylinder wires pulled out of the distributor cap and rigged up a 12volt power source that I would insert into the coil wire hole in the cap and a test light inserted into the cap wire hole that should correspond with the cylinder that should be firing. This will verify that the timing mark is correct and that your rotor is in its correct position to fire the cylinder and that the rotor button/cap are making contact because the light will light up. It should also verify that the cam is OK as both rockers will be closed. You could even go one step more and hook-up your compression tester to the cylinder that should be firing to see what the compression is at the time it fires. They should all be close and any big variances will indicate further checking of that cylinder.

If that all works, then you may have an electrical problem inside the distributor,ie bad condensor, bad points, bad ground, bad ground wire, burned up resistor wire coming from your ignition switch, bad ignition switch, bad engine ground, bad coil, and anything else you can think of.

I would check ALL the electrical things first before tearing into the engine. You might rebuild the engine and wind up with the same problems.


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## 64GTOConvertible (Aug 28, 2016)

^^^ All that.

Also check muffler bearings, blinker fluid and kniflinger pin alignment. 

(Thought you might use a laugh!)


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## 646904GTO (Feb 10, 2008)

Well I was able to get back to it today. I used my auto racing experience and marine engineering experience to guild me. I took the intake back off and noticed that the bottom of the intake gasket at cylinders 2-4 was still wet after sitting for more than a week untouched. Ahh I thought I found it! The head or deck was milled at the wrong angle...nope wasn't it. Then I saw the JB weld in the number 4 runner where the head porting had cut through the head casting and the builder JB welded the dime size hole. Found at least two more areas where the guy ported it right into the crankcase. Explains the 17 inches of vacuum at 2400 RPM and the 7 inches at 850 RPM. Anybody have a set of 1966 093 heads they want to sell?


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## PontiacJim (Dec 29, 2012)

646904GTO said:


> Well I was able to get back to it today. I used my auto racing experience and marine engineering experience to guild me. I took the intake back off and noticed that the bottom of the intake gasket at cylinders 2-4 was still wet after sitting for more than a week untouched. Ahh I thought I found it! The head or deck was milled at the wrong angle...nope wasn't it. Then I saw the JB weld in the number 4 runner where the head porting had cut through the head casting and the builder JB welded the dime size hole. Found at least two more areas where the guy ported it right into the crankcase. Explains the 17 inches of vacuum at 2400 RPM and the 7 inches at 850 RPM. Anybody have a set of 1966 093 heads they want to sell?


Well, I guess that would pose a real problem and was not something any of us would have guessed to be the problem -that's a first for the record books.

I would say it is obvious that the idiot who ported the heads_ knew_ he had blown through and destroyed them seeing you found the JB-Weld repair. Set of heads? I'd be tearing that engine apart before I did another thing on it. Hate to see you find JB-Weld in one of the cracked cylinders that the same clown may have tried to pass along because he didn't want to spring for a sleeve. The engine builder was probably a Chevy guy too. :crazy:


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## 646904GTO (Feb 10, 2008)

exactly what I told the owner. He was all for that. Mill comes out today


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