Car is running rough, stalls and has no power

SHERI

MEMBER
2003 PONTIAC GRAND AM
140 MILES

2003 Pontiac Grand Am. My car has a rough idle, stalls and has no power. We changed the plugs, wires, EGR valve, Cam Sensor, Coil pack, Changed oil and added Houes stabilizer, filled it up with High test gas and added fuel injector cleaner. The ICM tested out good at Autozone. We also replace the #1 injector (which was the original code) and checked the resistance on the Crank Shaft Sensor. It was.880. Sounds like the timing is retarded. Any suggestions?

4 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Wow, lots of expensive guessing here. Lets back up a minute. You need to start with a basic compression test to verify number 1 can fire. A vacuum test is next to see if things like cat converter being clogged is a problem. There are many checks needed before replacing anything else.

Roy

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Wednesday, February 1st, 2012 AT 5:45 AM

SHERI

MEMBER
3 POSTS

We did a compression test and a fuel pressure test, vaccuum test. We tested the resistance for the injectors and the computer kept giving us codes for a particular sensor. We would replace that sensor and then the computer would give us another sensor. We also replaced both Oxygen sensors and throttle position sensor. The code is now reading "PO3OO multiple misfires"

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Friday, February 3rd, 2012 AT 11:27 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

What was the compression? What was the fuel pressure? How much back pressure is from the cat?
A code never identifies a bad part, just a failed system. You need some help here as you have spent too much money on parts that did not fix your car. Did you check the fuel pressure regulator for a leaking diaphram? It would leak fuel into the intake system causing all kinds of issues.

Roy

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Saturday, February 4th, 2012 AT 1:16 AM

SHERI

MEMBER
3 POSTS

The compression, fuel pressure and back pressure read what it should according to my manuel. BUT, we did find the problem tonight. 3 rocker Arms stripped from the head. We pulled it apart and that was the problem, along with the push rods. My dad which has been a back yard mechanic for years never seen anything like this in his 60 years. Cant believe the car ran at all. Thank you for the help though!

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Sunday, February 5th, 2012 AT 8:36 AM