can't figure out why its running so bad!
01-11-2010, 05:46 PM
#1
can't figure out why its running so bad! been fighting this for months now. car is a 95 z28 A4 with bolt-ons and nitrous. the problems are: backfiring out of the exhaust (mostly when giving it throttle), running REALLY rich, idles low (around 500 rpm bouncing around), and a misfire occasionally at idle and when cruising. twice it hasn't wanted to start unless i opened the throttle all the way, and it did cut off a couple times when idling. started running rough on the way home from the track one night and it has progressively gotten worse. i don't have any shops around here with a scanner to read obd1 through an obd2 port on a 95, so i don't know what codes it may be throwing. i may be forgetting some symptoms and will add them as i remember/discover
i replaced my MSD opti with a stock one and it ran better, but still not great. sent the MSD back to have it replaced and put it back on. no change is how it ran and now it is running worse again. just replaced the o2's with new bosch units with no change. unplugged the MAF sensor while running and it immediately dies. unhooked the EVAP solenoid at the tb and it backfired out of the exhaust louder than i've ever heard. checked all other vacuum lines and can't find any leaks
I've considered the ICM, MAP, and the opti again, but don't want to spend anymore money until i get some more opinions.
i replaced my MSD opti with a stock one and it ran better, but still not great. sent the MSD back to have it replaced and put it back on. no change is how it ran and now it is running worse again. just replaced the o2's with new bosch units with no change. unplugged the MAF sensor while running and it immediately dies. unhooked the EVAP solenoid at the tb and it backfired out of the exhaust louder than i've ever heard. checked all other vacuum lines and can't find any leaks
I've considered the ICM, MAP, and the opti again, but don't want to spend anymore money until i get some more opinions.
