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Ron, ASE Certified Technician
Category: Pontiac
Satisfied Customers: 35496
Experience:  34 years as a Tech
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Was warmimg up and it stalled. now turns over and pops a

Customer Question

was warmimg up and it stalled . now turns over and pops a little but wont start ! has spark and fuel ?
Submitted: 6 months ago.
Category: Pontiac
Expert:  Ron replied 6 months ago.

My name is ***** ***** I am here to assit you with your question and help you resolve your concern.

Expert:  Ron replied 6 months ago.


In order for the engine to start and run you need good spark at the spark plugs, injector pulse at the injector, proper fuel pressure and good compression. If you are sure you have good spark as well as proper fuel pressure then the next steps would be to check the injector pulse and compression. Post back with the results and we can work from there.

Customer: replied 6 months ago.
nieghbor said it made a noise and stalled ! got a feeling it jumped time ! no timing marks how can i ck to see if it jumped time !
Customer: replied 6 months ago.
also cant locate a fuel pressure valve to ck pressure is there one on this engine ?
Expert:  Ron replied 6 months ago.

Terry , I suspect the same thing due to the backfiring. The best way to check this is to remove the spark plugs and run a compression test on the engine. If the timing has jumped you will see low to no compression on most cylinders.

Customer: replied 6 months ago.
120lbs on 2 / 120lbs on 4 / 30lbs on 6
Expert:  Ron replied 6 months ago.

The 30 lbs is a very good indication . I would have a look at the valve timing .

Customer: replied 6 months ago.
1and 3 and 5 are on rear of engine and diff to acess ! plugs are fuel soaked
Expert:  Ron replied 6 months ago.

Its likely that you going to find some of them low as well. This engine has a timing chain and a nylon gear. I suspect with the amount of miles you have on it your timing chain has jumped.

Customer: replied 6 months ago.
is this an in interference engine ?
Expert:  Ron replied 6 months ago.

The 3.4 is not considered an interference engine.

Customer: replied 6 months ago.
Hey Ron got her tore down timing marks are aligned and both gears are metal ?
Customer: replied 6 months ago.
Put it back together with new gears and chain since I had it also put on a new crank sensor behind crank pulley. There us a second crank sensor where is it located ? Still need some help here !
Expert:  Ron replied 6 months ago.

What is your compression reading now?

Expert:  Ron replied 6 months ago.

The second sensor is on the side of the block but it will not effect your compression. See it in the link below.

Customer: replied 6 months ago.
Starts but runs like a popping like a valve is bent or broken
Expert:  Ron replied 6 months ago.

That is likely and the cylinder that has the low compression is like where the problem lies.