At work a vr commodore with a buick has come in because of a misfire and the job has been extremely difficult, I am starting this post in case anyone has any of the same problems. Hopefully this might help somebody or someone might of had this problem previously. We fixed the misfire with new coil packs and dfi module. Keep getting engine running rich codes no matter what we do. Engine does not actually run rich, fuel pressure is very low upon start up though. Just about to run a few hundred tests and see what we can find. Will update on lunch break.
Sounds like it could need a new Fuel Regulator or maybe even pump. Clear the codes from the ECU and try it again. Could possibly need new O2 sensors.
Checked o2 censor all good, fuel pressure seems to be fine. Changed crank angle sensor in it today customer request. The problem with this job is that the guy has no money and keeps bringing in second hand parts for us to fit. Which is not really fixing anything. Fuel pressure regulator is what I thought instantly but it is only having fuel problems when cold... Have not done any further testing, that job is at the bottom of the list at the moment lol
Have had the scan tool in the car the whole time, I erase all codes after everything and it keeps throwing the running rich code
So it is running rich only while in open loop mode, then settles down and runs better when it goes into closed loop?
mat or ecu temp sensor maybe? how are the temp readouts on the scan tool once it's been idling for a while and up to temp? leaving a car to idle i've notice once the engine get's to 95-98c and the fan kicks in the intake temp should be around 55-70 while stationary and idling (depending on the ambient temp).
You keep saying it keeps throwing a rich code, what is the code number exactly. Would be a lot easier rather then grasping at straws.
