Hey everyone, I have a 1998 V6 that's been having similar problems for a while now. I've replaced an O2 sensor, two relays gone bad, and the MAF sensor in hopes of fixing the problem, and a lot of cash later the problem still persists. When I turn the key to the on position without cranking the engine I can hear the pump coming on right away, the car will just crank and sorta sputter and shake but still turns on every time. All the fuses seem to be in good working order. A mechanic at Pepboys diagnosed it and told me it was the air/smog pump, but from this thread i'm starting to think it might be the crank sensor. Any help and advice will be greatly appreciated, thanks!
Sure would be nice to know the results of the "other tests" called out in this thread. key cycle, theft light, holding pedal half way open.
I don't under stand what "sorta sputter and shake but still turns on every time" means. Does it crank but not start? Does it crank for a long time and then start? Does it crank, start, and then die?
Are the any check engine DTC codes? If so, post the full DTC code. All of them.
FWIIW, the crank position sensor (CKP) is a no start sensor. What that means is if the CKP is bad, the car will never start.
For the V6 motor, the cam position sensor can also cause hard starts.
What is the condition of the ignition system? Spark plugs and wires?
Have you cleaned the MAF?
Have you done a through inspection for vacuum leaks?
Are there any exhaust leaks?
What problems are you having with the air system? The can sometimes rust out creating leaks that make more problems.
And finally, what about the base engine. These V6's are bad about blowing head gaskets. How's the compression? Using any coolant? Any water in the oil?