Car: 1989 325is
So I've been having this problem for maybe 2.5 months now, it started all of a sudden one day. Car was running great up until then.
Symptoms:
Car will stumble/cutoff at some point between 4500 and red line. the RPM seems to depend on both engine temperature and load. Runs great up until then.
By Stumble/cutoff I mean the motor will all of a sudden start missing, or maybe cutting fuel or spark, loss of all power. If you stay on the throttle, it will continue to go up in jumps, and it struggles (continues to miss/cutoff/stumble). Sort of like the motor is turning on and off and on and off...
When the motor is COLD, I can run it up all the way to redline no problem (which I hate doing cold). Once hot, and sitting there (no load) it happens around 5700-6200 RPM. If hot and under heavy load (going up a hill) it happens near 4500 RPM.
Modifications to the car: This car does have a Miller Mass Airflow meter.
What I've tried so far:
1. Replaced CPS
2. Replaced and tested TPS
3. Replaced spark plug wires
4. Checked with a timing gun and it stayed lit the whole time during the stumble (not sure if this is truly a valid test...)
5. Cleaned C191 connector (it looked fine either way)
6. Checked fuses for continuity
7. Fuel Pressure is good, (also, pump/filter/regulator recently replaced)
8. Checked function of coolant sensor and switch
The distributor and coil have been replaced in the last 1000 miles...
The next thing I'm going to try is to replace the ECU and Flowmeter back to the original, but I would be very surprised if this changes anything.
Any ideas, suggestions would be greatly appreciated as I'm running out. Let me know if any questions....
So I've been having this problem for maybe 2.5 months now, it started all of a sudden one day. Car was running great up until then.
Symptoms:
Car will stumble/cutoff at some point between 4500 and red line. the RPM seems to depend on both engine temperature and load. Runs great up until then.
By Stumble/cutoff I mean the motor will all of a sudden start missing, or maybe cutting fuel or spark, loss of all power. If you stay on the throttle, it will continue to go up in jumps, and it struggles (continues to miss/cutoff/stumble). Sort of like the motor is turning on and off and on and off...
When the motor is COLD, I can run it up all the way to redline no problem (which I hate doing cold). Once hot, and sitting there (no load) it happens around 5700-6200 RPM. If hot and under heavy load (going up a hill) it happens near 4500 RPM.
Modifications to the car: This car does have a Miller Mass Airflow meter.
What I've tried so far:
1. Replaced CPS
2. Replaced and tested TPS
3. Replaced spark plug wires
4. Checked with a timing gun and it stayed lit the whole time during the stumble (not sure if this is truly a valid test...)
5. Cleaned C191 connector (it looked fine either way)
6. Checked fuses for continuity
7. Fuel Pressure is good, (also, pump/filter/regulator recently replaced)
8. Checked function of coolant sensor and switch
The distributor and coil have been replaced in the last 1000 miles...
The next thing I'm going to try is to replace the ECU and Flowmeter back to the original, but I would be very surprised if this changes anything.
Any ideas, suggestions would be greatly appreciated as I'm running out. Let me know if any questions....
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