So, I've been messing around with a '85 318i which seems to have an odd misfire. It misses a little at idle, then if you go to accelerate from a stop it misfires and struggles, but then when you finally reach ~3800 rpm it just revs like nothing was wrong. I think it's odd because the usual misfires occur at higher rpm, but not this one. The car feels like it has VTEC that engages at 3.8k rpm's!
There is a reman ecu, reman afm, new CTS (wiring is good from the CTS to ecu), grounds have been cleaned and check out to be ok with a meter, there are copper denso plugs that are ok (but black from the car running rich), the cap/rotor/wires appear to be in good shape (no arcing when misting water around the wires), throttle switch clicking (couldn't reach the connector to get the meter on the pins though to check operation of the switch itself), and fuel pressure is between 40-44psi during the entire rev range (when running rough and when running smooth above 3.8k rpm). I know it's running rich at the lower rpm's as it's sputtering as you can see/smell the fuel coming from the exhaust (and it had a really good backfire once when shifting from first to second, haha). I disconnected the throttle switch, no change. I disconnected the barometric pressure sensor, no change. I bumped the timing a tad advanced, no change (other than a slightly higher idle). I disconnected the ICV, no change. I swapped an ignition coil from another E30 that runs great, no change.
What else should I be looking for or testing? Any ideas? Thanks!
There is a reman ecu, reman afm, new CTS (wiring is good from the CTS to ecu), grounds have been cleaned and check out to be ok with a meter, there are copper denso plugs that are ok (but black from the car running rich), the cap/rotor/wires appear to be in good shape (no arcing when misting water around the wires), throttle switch clicking (couldn't reach the connector to get the meter on the pins though to check operation of the switch itself), and fuel pressure is between 40-44psi during the entire rev range (when running rough and when running smooth above 3.8k rpm). I know it's running rich at the lower rpm's as it's sputtering as you can see/smell the fuel coming from the exhaust (and it had a really good backfire once when shifting from first to second, haha). I disconnected the throttle switch, no change. I disconnected the barometric pressure sensor, no change. I bumped the timing a tad advanced, no change (other than a slightly higher idle). I disconnected the ICV, no change. I swapped an ignition coil from another E30 that runs great, no change.
What else should I be looking for or testing? Any ideas? Thanks!
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