Need help! Sputter/Misfire 325E

[iamkorruption]

My 1985 325E is giving me a hard time lately. Ran perfect until I took it to the car wash the other day then started my misfire or sputter at idle and when giving it throttle. If you are very light on throttle it goes up in RPM but any more than a touch it sputters like crazy and will not accelerate. I am also now having a problem that when flooring gas pedal (and only when flooring) after a few seconds the car will just stop responding to throttle and give up then come back as soon as i let up and give it any less than full throttle.

Smoke tested found no vacuum leaks. Injectors cleaned and flow tested. Fuel pressure is good. Timing is in spec. Valves adjusted.

New parts - Alternator, coolant sensors, plugs, wires, ignition coil, idle control module, idle control valve, DME, distributor rotor and cap, transfer pump, main fuel pump, valve cover gasket.

Need help on where to go from here.

[MrBurgundy]

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[wilholl]

Some thing to consider:
Check for water in the O2 sensor connector and water in the injector harness connector where it connects to the engine harness (driver side of the block, under the intake manifold.
Water likes to collect in these connectors and makes the engine run terrible.
This is based on my personal experience...

[iamkorruption]

Sorry crank position sensor and flywheel reference were also replaced and tested after replacement. No water in 02 sensor connectors and unplugging them doesn't change anything. Where is the injector harness connector? I have looked under the intake manifold and cannot find anything.

[EyExR]

Sorry crank position sensor and flywheel reference were also replaced and tested after replacement. No water in 02 sensor connectors and unplugging them doesn't change anything. Where is the injector harness connector? I have looked under the intake manifold and cannot find anything.

It's called a C191 connector. You can see how it comes off the injector harness here:


Location:


Feel around under the intake. It's there. Or remove your AFM and airbox to get a better grab at it.

If that doesn't solve your problem I would also test a spare AFM if you can.

[iamkorruption]

I have a brand new AFM installed in there and it tests fine. My car does not have that connector underneath. Is there a chance the 325e doesnt have it?

[iamkorruption]

Still havent found the problem. Have tested multiple wires and sensors for a while now.

[MrBurgundy]

check the ring on the harmonic balancer. maybe the cps is having a hard time reading the crank position

[iamkorruption]

My crank sensor is in the bellhousing and all teeth in there are intact.

[EyExR]

I have a brand new AFM installed in there and it tests fine. My car does not have that connector underneath. Is there a chance the 325e doesnt have it?

Whoops! Sorry bud you're right. You have a Motronic 1.0 system. No C191

Where did you get your new AFM from? BMW? I'm VERY suspicious of rebuilt ones depending on where they're coming from. I'm not sure if the connectors are the same or what but I do know the AFM has to be specific to your engine. In your case a M20B27.

[iamkorruption]

Brand new oem afm. Any other suggestions/ideas?

[EyExR]

Throttle position switch?

[iamkorruption]

Throttle position switch new as well and tested/adjusted just in case.

[Kershaw]

Fuel pressure regulator.

And / or
fuel filter
fuel pump(s)

I found several times that the scenario you describe to be caused by fuel issues, not electrical issues. And you seem to have covered the electrical said in any case.

[EyExR]

Grasping at straws. Could it be your airbox got flooded?