I have a 2000 pontiac grand am 3400 3.4 liter. It had cylinder 5 missfire until I got new wires and ac delco plugs, a new fuel filter, with each cylinder having 150 on compression test now I got the code of random missfire.
Random misfires are from injector and low fuel pressure problems
SOURCE: 2000 Pontiac Grand AM trouble code P0300
Im surprised that didn't fix it. On the Quad4 engine its usually a cracked coil housing.
Have you checked:
The crankshaft position system variation compensating values are stored in the PCM non-volatile memory after a learn procedure has been performed. If the actual crankshaft position system variation is not within the crankshaft position system variation compensating values stored in the PCM, DTC P0300 may set.
SOURCE: 2000 Daewoo Lanos intermittant misfire trouble code
check fuel filter and check fuel for water or contaminents
then check fuel pressure with gauge also while driving
may have pin hole in leads - spray water with salt solution over HT leads while engine running and then rev to see or here spark jump(missfire)
recheck spark plugs - did you crack any on installation/removal/installation?
what are the codes and description if stored?
what is engine live data parameters like do they look normal (right specs for range/operation)?
SOURCE: 2002 grand prix car was not getting good gas
this commpression test may point to your problem. my question is "have you" been smelling a light aroma of antifreeze"? if the answer is yes then theres your problem. pontiac made this model with plastic manifold gaskets. this is a known defect. i had this problem and bought metal gaskets and replaced both. additionally i changed out all the spark plugs. aday job and not for the novice. get a manual and spec. you will also need a good torque wrench. as you take out the push rods note which hole each went in. the push rods are different sizes for the exhaust and intakes. good luck. on a scale of 1-10 i would give it an 8. this is not a novice mechanic job.
SOURCE: 98 grand cherokee cyliner 1 misfire,, HELP ..
it has cap not coil pack , you try decarb might get lucky any ticking ? next is leak down on the cylinder and determine weather rings or valves how many miles wheat are the engine codes now check and the plug again , did it have misfire on the same cylinder before you worked on it adn after you worked on it. What is running compression. all these answers are to answered some you can do some will need more tools.
Testimonial: "whats decarb.. ??? and whats leak test on the cylinder ? please help ..."
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