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Discussion Starter #1
Hi Guys,
I have a 1967 Lemans that have spent 6 years restoring and have been driving for 2 years since completed. Had the Quadrajet carburetor rebuilt last year. Has been running great until yesterday. While driving it starting stuttering and stalled so had it towed back home. Started it up the next day and ran great for 5 minutes then started stuttering again and now will not even start. It fires but will not start. what I have done to troubleshoot the problem so far is change the gas filter and confirm that it is getting gas when depressing the throttle which it is. Unfortunately I am weak when it comes to engine troubleshooting skills and have not had to do to much with it since restoring it. I could take it to the local garage but part of the fun of owning one these cars is being able to maintain it. I am hoping someone can give me some tips as to how i should go about troubleshooting this problem.
Any advice would be great and would like to mention this website has been a great source of information during my restoration years.
 

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Hi Guys,
I have a 1967 Lemans that have spent 6 years restoring and have been driving for 2 years since completed. Had the Quadrajet carburetor rebuilt last year. Has been running great until yesterday. While driving it starting stuttering and stalled so had it towed back home. Started it up the next day and ran great for 5 minutes then started stuttering again and now will not even start. It fires but will not start. what I have done to troubleshoot the problem so far is change the gas filter and confirm that it is getting gas when depressing the throttle which it is. Unfortunately I am weak when it comes to engine troubleshooting skills and have not had to do to much with it since restoring it. I could take it to the local garage but part of the fun of owning one these cars is being able to maintain it. I am hoping someone can give me some tips as to how i should go about troubleshooting this problem.
Any advice would be great and would like to mention this website has been a great source of information during my restoration years.
"It fires but will no start" What does that mean? That it has spark at the plug wires? Does it have spark at the end of the plug wires when held close to metal while cranking?
 

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https://www.amazon.com/ENA-Universal-Automotive-Motorcycle-Fool-Proof/dp/B07GHBNFKZ/ref=asc_df_B07GHBNFKZ/?tag=hyprod-20&linkCode=df0&hvadid=312061979255&hvpos=1o5&hvnetw=g&hvrand=6174032471127441733&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033507&hvtargid=pla-582656637262&psc=1

one of these is very handy .....
it blinks with every spark on that plug wire ...
it doesnt tell how strong ... but if you do or dont... are they dry ? wet ? black ? orange?

pull a couple spark plugs "1" at a time.
it takes ..air , spark, fuel , and compression = to make an engine a possible runner

I wish you the best .... sounds similar to water in the gas ... did you recently fill up ??
 

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Discussion Starter #4 (Edited)
In response to RMTZ67 when i say "It fires but will no start" would mean it will run for 2 seconds then stalls. it will do this continuously but never stay running. I assume it has spark based on the fact that it will run for a couple of seconds but will test for spark at each spark plug once i have someone to turn the ignition for me.
In response to BLK69 JUDGE, Yes I did recently fill up the gas tank just 2 days before the problem occurred. If there is water causing the problem should i try using something like Iso heet which helps displace the water and if that doesnt work drain the gas tank to rule that out as being the problem. As I mentioned I am not very good with engine mechanics and so can you clarify what you mean When you say "air spark fuel and compression = possible runner".
I plan on getting the inline spark checker today. seems like a handy tool to have for quick testing.

Thanks to both of you for the quick response

Today I drained gas line,replaced inline gas filter, pulled each spark plug,cleaned them and blew out cylinder's with air hose. seemed to be a lot of fluid in the cylinders I am guessing flooded with gas. After that the car started up and run for about a minute then started stalling again.
 

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In response to RMTZ67 when i say "It fires but will no start" would mean it will run for 2 seconds then stalls. it will do this continuously but never stay running. I assume it has spark based on the fact that it will run for a couple of seconds but will test for spark at each spark plug once i have someone to turn the ignition for me.
In response to BLK69 JUDGE, Yes I did recently fill up the gas tank just 2 days before the problem occurred. If there is water causing the problem should i try using something like Iso heet which helps displace the water and if that doesnt work drain the gas tank to rule that out as being the problem. As I mentioned I am not very good with engine mechanics and so can you clarify what you mean When you say "air spark fuel and compression = possible runner".
I plan on getting the inline spark checker today. seems like a handy tool to have for quick testing.

Thanks to both of you for the quick response

Today I drained gas line,replaced inline gas filter, pulled each spark plug,cleaned them and blew out cylinder's with air hose. seemed to be a lot of fluid in the cylinders I am guessing flooded with gas. After that the car started up and run for about a minute then started stalling again.

Sounds like it may indeed be flooding - carb problem.
 

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Discussion Starter #6
When checking the Carb after stalling It looks like the gaskets are wet from gas? I am a little Leary about pulling the carb off and inspecting it but not afraid to try. I have the Cliff Ruggles book on how to rebuild and modify Quadrajet Carburetors which should be helpful. I was able to slip a flat plastic tip in from the top of the carb and the float does move up and down.
 

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Discussion Starter #7
I pulled the carb off today and took it apart. not completely but enough to check for anything that would cause the float to stick or something that would look out of place. One thing i noticed is all the bolts and screws didn't seem to be very tight and was hoping that may have been part of the problem. after reinstalling the carb the problem is still there. Runs for a few seconds then stalls. If i rev it up and maintain high rpm's it will stay running for a short time. Now i am at the point of replacing things like the fuel pump which I have never changed during the restoration.
 

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If it's flooding that much the exhaust would be spewing a lot of BLACK smoke. After it stalls, quickly look down the carb with a flashlight and see if you see fuel still leaking in. That would show too much fuel is getting in and you have a float or needle problem and a fuel pump is not your problem, you may be getting too much gas.

You could try some starting fluid. Have a friend start it and you be ready at the carb to shoot some in and see if you can keep the engine running. If you can, then it would be too little fuel or a pump or carb problem.
 

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Discussion Starter #9
Took the carb off again, removed float, main jets, and cleaned everything. I am not an expert on these carbs but didnt see anything that would be a problem. I set the mains jets initially at 2 1/2 turns out after putting it back on. the manifold gasket didnt look bad so reused it which may have been a mistake. I also swapped out the fuel pump, distributor cap and rotor. I am getting spark at the plugs. confirmed both coil and voltage regulator are within specs. Had it running good once for about 10 minutes then suddenly shut down.
 

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Sounds like it is flooding, can you just lean out the mixture a bit, turn it in to 2 1/4.....then 2.....can you get it to run there?

Floats set too high can cause flooding as well...
 

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Discussion Starter #11
Will try leaning out the main jets. What is the best way to adjust the carburetor float. i thought just filling the bowl and bend the float arms would work but want to make sure i do it the right way.
Thanks for the advice.
 

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I am probably thinkin with my fingers but...

here I go ........

If I had rebuilt the carb and it ran ok for 10 minutes then stalled ... and I was in my garage or at home
in the drive way and it stalled...
I would think did it just shut off ? or did it chug a bit b4 stalling ....
I would pop the air cleaner off.... smell for gas .... check the filter if I had a clear style on it...
look for fumes coming from the carb....
turn the key off,,, 5 minutes ago ...
bend over and pump the throttle and see if theres any accelerator pump squirt ...
yes or no
2 different dirrections of action now ...

look for gassy areas on the carb...

pull a couple rear plugs ?? wet ?? dry?? black ?? gray ??

we always ... once the motor is warmed up and the choke off...
turned the idle mixture screws in till the engine started to bog a bit and run lean and turn em back out 1/2 to a full turn
when the engine idled better ... do the other side ... rev it up a few times let it idle ,,, rev it up again ... idle for a few seconds..... adjust em agian..... in slowly till the engine starts to idle down then out till smooth 1/2 -1 turn
shouldnt be over 1 turn usually

good to go ... as long as your idle rpm was set pretty close...
 

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Discussion Starter #13
After getting frustrated I took some time off in trying to resolve the no start issue. Plus living up north Driving season is over for me. I am ready to get back at it and decided to do a compression test and found that all 8 cylinders on a stock 326 engine were reading between 92 to 100 pounds of pressure. Of course this is with the engine cold as i am not able to get it running but wanted to see if that was a normal reading. the compression gauge was one I bought at harbor freight and can only assume it is somewhat accurate. while i had all of the spark plugs pulled out i used a dial indicator to confirm number one piston is at top dead center which indicated the harmonic balancer lining up at zero degrees. Also confirmed number one spark plug wire on the distributor cap was lined up with rotor. if anyone can see anything i have missed please reply.

Thanks in advance
 

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Be sure to check the rubber gas lines at the gas tank too. Over time, these dry rot and crack open. Did you try a gas "drying" agent to remove any water you may have gotten from the recent fill up?
 

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Discussion Starter #15
All of the gas lines were replaced during the restoration within the last 6 years but will check the rubber lines at the gas tank just to confirm. I initially suspected water in the lines but took some from the tank by way of the fuel pump. didnt see any signs of water or discoloration. Added 2 containers of Heet gas treatment as a precaution.

Thanks for the quick response
 

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Discussion Starter #16
Can anyone tell me if 92 to 100 pounds of cylinder pressure is normal on a stock 326 engine under cold conditions.

Thanks
 

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Can anyone tell me if 92 to 100 pounds of cylinder pressure is normal on a stock 326 engine under cold conditions.

Thanks

The factory manual says 150-170 at cranking speed. It does not say anything about cold or warm.

Did you do your test with all plugs removed and both choke and throttle blades fully opened (gas pedal to the floor)?

If your choke is not operating correctly and it is remaining closed when you go to start the engine, the engine will not get enough air and also act as you describe.
 

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Discussion Starter #18
I did not test with both choke and throttle blades fully opened. I will retest and hopefully get better results.

Thanks for the quick response Jim.
 

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I did not test with both choke and throttle blades fully opened. I will retest and hopefully get better results.

Thanks for the quick response Jim.

Make sure your battery is fully charged so the engine will spin over fast.

Hopefully your numbers will be better. Did you replace the timing chain? It is possible the timing chain has slipped which will affect valve opening/closing points and may not be building up cylinder pressure as needed.

That would involve finding TDC on No. #1 piston and checking to see where the timing mark on the balancer is on the timing gear cover scale, and watching the rocker arms on No. 1 cyl to make sure both are closed at TDC. Just something to consider.

You can also test the timing chain for excessive stretch easy enough. Pull the distributor cap leaving the rotor on. Make a mark on the balancer that will line it up with the "0" mark on the scale (you don't have to line up the factory line on the balancer with the "0" mark on the scale for this test). By hand, rotate the balancer to the right until you see the rotor move -then stop. Note where the line on the balancer is on the scale. Now rotate the balancer to the left until the rotor moves -then stop. Note where the balancer mark is. Repeat to verify your findings. You should not have more than about 5 degrees movement at the balancer as measured against the timing scale going right to left at the point the rotor moved. Any more than about 5 degeees and the chain/gears need replacement. The best situation would be the rotor moves immediately the minute you rotate the balancer. You can do this check with the spark plugs out and can probably turn th engine using the fan blade seeing no compression will build in the cylinder. :thumbsup:
 

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Discussion Starter #20
Just recently had Knee surgery so wont be able to check the cylinder compression for another week. I did replace the timing chain during the restoration. Can I assume if i just swapped the timing chain without rotating the engine crank it should still be lined up correctly? i drove the car for 2 seasons since without any problems. I will try your advice for excessive stretch on the timing chain.

Thanks for the advice
I will let you know the outcome once i get back on my feet.
 
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