I've got an issue I'm having trouble diagnosing. We're trying to test as many potential issues as possible without having to go through the "buy a part, see if it fixes it" routine.
So far all I really know is it's affecting air/fuel mixture.
Car:
1989 325is
stock M20B25
Issue:
- Car will fire up, bog, then die unless you give it gas.
- Won't hold an idle when engine's cold and seems to be because there's much more fuel then air.
- After warmed up, car pulls pretty smoothly through the rev range, however still running very rich. Will idle, but at around 450-550 RPMs, barely staying alive.
- Car ran better (yet still a bit rich) before I cracked the oil pan a few weeks ago. Only a hairline - oil pump was fine.
- CEL comes on sometimes but shuts off as soon as gas is applied or let off of.
Diagnostics Attempted / New Parts
- New spark plugs
- New oil pan and gasket
- New intake bellow replacing cracked one
- Swapped between (with no result):
Plug wire sets
DME's
ICV's
AFM's
FPR's
O2 Sensors
- Sprayed carb cleaner around vac lines during cold start (no RPM increase)
- Currency tested:
TP sensor
ECT sensor (reading was a little off but didnt seem too drastic. There's also a white ECT on the car instead of a blue one. Don't know why...)
- Idle drops when removing oil cap or dipstick (gauging crankcase vacuum)
Ordered for Near Future:
- Magnecor plug wires - 8mm Race (Car came with BavAuto wires, and I can hear them ticking and cross-firing sporadically)
- $300 worth of gaskets and seals for almost everything in the bay. Going to do a mild rebuild, but would like to source this issue first.
Again, I'd like to run as many tests as possible without buying boxes full of parts to figure out the issue - so if you've got anything I should try, let me know.
Any help is appreciated.
So far all I really know is it's affecting air/fuel mixture.
Car:
1989 325is
stock M20B25
Issue:
- Car will fire up, bog, then die unless you give it gas.
- Won't hold an idle when engine's cold and seems to be because there's much more fuel then air.
- After warmed up, car pulls pretty smoothly through the rev range, however still running very rich. Will idle, but at around 450-550 RPMs, barely staying alive.
- Car ran better (yet still a bit rich) before I cracked the oil pan a few weeks ago. Only a hairline - oil pump was fine.
- CEL comes on sometimes but shuts off as soon as gas is applied or let off of.
Diagnostics Attempted / New Parts
- New spark plugs
- New oil pan and gasket
- New intake bellow replacing cracked one
- Swapped between (with no result):
Plug wire sets
DME's
ICV's
AFM's
FPR's
O2 Sensors
- Sprayed carb cleaner around vac lines during cold start (no RPM increase)
- Currency tested:
TP sensor
ECT sensor (reading was a little off but didnt seem too drastic. There's also a white ECT on the car instead of a blue one. Don't know why...)
- Idle drops when removing oil cap or dipstick (gauging crankcase vacuum)
Ordered for Near Future:
- Magnecor plug wires - 8mm Race (Car came with BavAuto wires, and I can hear them ticking and cross-firing sporadically)
- $300 worth of gaskets and seals for almost everything in the bay. Going to do a mild rebuild, but would like to source this issue first.
Again, I'd like to run as many tests as possible without buying boxes full of parts to figure out the issue - so if you've got anything I should try, let me know.
Any help is appreciated.
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