Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
If there are 2 cylinders missing all the time then possible the ICM.
Those are only codes. Does it show the MAP readings, TPS readings? engine temp readings and so on?
Your reading on the fuel is good, it is before the regulator that is needed, which you indicated you did.
OK, the short term fuel trim is concerning, it should be near 0. This means it is seeing too much fuel, but could be due to the misfire.
Using insulated plies, pull the plugs off one at a time, plug wires that is, and see if one or 2 don't spark or cause the engine to run differently.
I have to agree, this is a head scratcher. Injectors could, but so could the PCM and the timing chain. If the chain has jumped, the only way to know for sure is to remove the timing cover and inspect. Testing the PCM is difficult, but given the location, wiring in that area can be bad. Often the PCM is the last guess.
$60 for the programming is not bad at all. I think if you are wanting to try a PCM, this is a valid option.
Ok, The injectors may be leaking but they may be over-fueling because of a false reading. Have you tried to run it with the oxygen sensor unplugged?
OK, I have asked another experts opinion to see what we are missing and he suggest checking the Map sensor seal, the injector seals and lastly the head gasket.
Not often is there a post this long, but I have had a couple that were more than 60 replies.
You have paid and thank you.
I have to agree, not only because of the fact we have looked at most everything else, but because of the piston to lifters.