1999MY GC8 2.5 N/A intermittant starting issues
Hi!
writing from germany - a buddies GC8 has been having some issues.
some backstory: the car is a 1999 gc8 2.5 N/A, automatic.
the car always ran just fine, started up on first crank. after the car sat for around 3 months, it started having intermittant issues. sometimes it would start, sometimes it wouldn't. when it doesn't start, it cranks, but doesn't fire, no matter how long it cranks.
BUT - sometimes, the car starts, then instantly dies - like someone turned off the ignition.
then, after 5 or more ignition cycles, it starts up and runs just fine. there is a immo code in the ECM, but the immo light in the cluster doesn't light up (key is being detected) the coil in the ignition barrel is functioning fine, and even with the second key, the issue persists.
The crank position sensor has been replaced, and the fuel pump has been checked. even with the relay bridged for the fuel pump to run constantly, the car instantly does, or does not start.
we are very stumped with this issue - does anyone have any advice?
thanks :)