I'll pay anyone if you can solve this problem!!!

[secretaznman4u]

Okay, this is really Off topic, but NO ONE has been able to resolve it! So i figure why not here, and I am serious I'll pay you (nicely) if you can figure out whats wrong. I am about to push this off car off a cliff!!!

I have a 93 325is with a slushbox. Here's the problem. the car just dies whenever it wants, but it restarts immediately, BUT the rpms shoot up to 4k and just sits there. I have to stop and restart many many times before the rpms will go back down. I have so far replaced the MAF, the ICV and the Plugs and still its dying ARRRR!!!! Another thing I have noticed, when it does stall the RPM(tach) needle jumps over 7k and the engine dies, (the actual engine speed doesnt jump). I am so confused and lost. the car has been at stealership and they charged me 3 hours of labor and can't see anything wrong with the car and the car is now at a local mechanic for 2 days now with no luck. Much help is needed.

TIA,

ERIC

[jenmcd]

Cam or crankshaft position sensors??? These caused rough running and a few stalls but not the rpm spike in our car.

Keith

[Dave at Pelican Parts]

In general, high RPMs with the throttle nominally closed are caused by two things. One is air somehow getting from one side of the throttle to the other, either through a vacuum leak or through a designed-in bypass like the fast idle valve. The other is advanced ignition timing.

4K RPM sounds like more than could be accounted for by overly -advanced timing, but the 7K spike in the tach definitely points toward an ignition fault of some kind. Similar problems in other cars have been caused by an "ignitor", which is more or less a spark initiation gizmo. Loose wires to that component cause similar things.

I wonder if it's possible that a flakey sensor would fool the DME into opening a throttle bypass of some kind, like a deceleration valve? Hmm...

From the sound of it, you may have more than one problem, and they are interacting in funky ways. I would try to isolate the ignition system problem (assuming there reall y is one) if possible. Perhaps a complete known-good distributor could be swapped in?

Another possibility is something I've read around here about water getting into the DME ECU and causing all kinds of really weird behavior. Evidently some E36 cars have a water drain near the ECU that is easily plugged, and the water can short out components inside the ECU if it sits long enough. That is also worth checking.


...If I'm right, all I ask is that you consider buying parts from Pelican the next time you need something...

--DD

[Roald]

at idle there is a steady supply of fuel while air supply is varied trough idle control valve. also once the oxygen sensor is heated up it comes into play to adjust the fuel/air ratio. neither bad oxygen sensor nor worn out ICV, which in your case already have been replaced, can cause such spikes as 4000 rpm!
also some unmetered air sucked somewhere behind the air flow meter unlikely will cause such a thing. rough idle and operation yes.
i'd suggest you to disassemble the intake in order to look at throttle body its linkage and check throttle position sensor! i would suspect that a spike in rpms is caused by open throttle when it is supposed to be closed!
as to your dealer then unfortunately it is another story of a bad treatment of a customer which has become a norm in these days of sophisticated cars and diagnostic stands!
the place with a nice showroom and full of plug&play "experts" is the worst place to take your car to!

[Ad Hoc]

While not a comprehensive solution - and possibly not a solution at all - I will emphatically confirm what Dave from PP said (I've had mine react negatively from the cause he stated):

Another possibility is something I've read around here about water getting into the DME ECU and causing all kinds of really weird behavior. Evidently some E36 cars have a water drain near the ECU that is easily plugged, and the water can short out components inside the ECU if it sits long enough. That is also worth checking.

I have a '93 325i. The DME (DME, ECU and ECM are all the same thing - the engine control computer) sits in the firewall on the passenger side. When your typical car wash dumps on average 45-50 gallons of water on the car, the ability of the car to effectively drain water away from the DME is compromised - computer chips and water don't mix. The DME is easily removable to check for moisture and/or corrosion.

Even if this is not the cause of your problems, you should take appropriate steps to prevent your DME from future water damage. And since you own a '93, avoid car washes at all costs - wash it by hand with a bucket and a hose

[BMWCowboy]

Did the dealer say there were any faults in the DME???? Diffently sounds like you have more than one problem>>but mainly DME
which should have stored faults under those conditions. These cars not only had the drain problem, they also shorted out causing all 6 coils to go bad + the DME>>If you were charged 3 hours then they should have said something more then >>nothings wrong?¿?....Is your carpet foot matt pushing on ur gas pedal??....have seen this numerous times also

[elkabe]

Eric

If I understand your post correctly, your engine dies after the rev counter shoots up to 7000 although the engine does not actually accelerate. The engine is shutting off because your RPM sensor says that the engine is overrevving. This messes up the computer and your air/fuel flows on subsequent starts while the sensor is still indicating incorrectly. Have the RPM sensor replaced and check for broken/cracked wiring from the sensor. This should take care of your problem and shouldn't cost too much. This is an intermittent problem so there is a good chance that the mechanics won't find it unless it fails while they have it on their monitor. Replace the sensor anyway.

Larry

[BMWCowboy]

this car doesnt have any over rev protection>>only knock sensors would send cut off

[Step On It!]

Check under the gas pedal for dirt buildup or anything sticky...