Thread: Slow Start...sometimes

I have a 99 GTP and it starts slow sometimes. Randomly sometimes when hot sometimes when cold. I changed the cam and crank sensors and it seemed to help a little. I have a parts car available to test parts. Would a control module do this too? Only other thing I can think of is fuel pump/cracked line.

It seems like it would be ignition related since you smell fuel after cranking and starting.

The FPR looks new as were the cranks sensor and cam sensor although I think they were cheapos like Autozone or something. I could change it easy enough but the randomness has me puzzled.

Oh, I also swapped out the MAF sensor as well.

Have you tried a Case learn?
(Crankshaft position sensor Relearn)

I haven't done a case relearn yet. Good idea though. The fuel trims were -3 to -5 so a little rich but not too bad.

Negative numbers means your PCM is cutting fuel I think.
So I think you would be lean.
Don't hold me to that thought.

Negative means it is pulling fuel, you want to err on the rich side. I did not mess with factory tune. Those are short term fuel trims. Onve I get the pulley on I am going to have it dyno tuned on a load bearing dyno. I have not checked fuel trims since my K and N drop in and high flow down pipe and resonator delete. I don't believe a dirty throttle blade has anything to do with it. Case relearn makes sense and iim gonna swap out control modules as I have a spare along with lots of stuff for test parts.

Tried the control module and coils, no difference.

Are you talking the engine to body ground and where the battery ground meets the fenderwell? Good tip, I will check it.