HELP 535is

[patmchugh]

Not too long ago, i was driving along and my 1987 535is engine started to pull instead of push. The engine refused to generate power and i barely made it to a parking lot. I could not find a tow truck that was able to tow it, because it rides too low, so i went over there (it was 36 degrees) with my tools and replaced the distributor cap, rotor, and coil, thinking that i had blown one of the three. All three were in very bad condition, and were ready to be replaced, but the car still had the same symptoms. The symptoms are: The car starts fine, and idles ok for a minute or so, then it idles at 500rpm and very rough. THe engine will sort of rev, but it will not give constant power. If I give the gas pressure, the rpm's will rise, then fall, and the engine will die. I thought that it might be a clogged fuel filter, but that didn't help when i replaced it. Both fuel pumps are working. I decided to test the fuelk pressure regulator, by squeezing the return line to build pressure and the engine ran properly!! i replaced the fuel pressure regulator and the car still had the same problem. I am absolutely stumped. Any advice on what to try next?

[Brother]

Did you find out what caused this??????.

The fuel pump, filter and regulator have been replaced with no results. This last weekend I replaced the MAF meter and the ICV. I was able to get the car to run again.

Symptoms. It will start cold and run perfectly with a smooth idle. As soon as it warms up the idle gets irratic and lumpy.

The other odd thing I notice is when I pull the throttle and hold it, the RPM's drop off and while holding it still they'll come back up. It acts like a fuel problem.

I would appreciate any advice..

Thanks

[patmchugh]

yeah, i figured it out. The problem was, that i had cut the wires to my oxygen sensor to bring the exhaust down, and when i reconnected it, i just used regular electrical connectors. Water then entered the connectors, and short circuited my sensor. I had a HECK of a time figuring it out. I ended up just wrapping the wires very tight in electral tape individually in the mean time while i wait for a new sensor to arrive. This sympton could also be caused by a broken oxygen sensor, so that would be a very valid thing to check. good luck

[Brother]

Thanks very much for the reply... I have the O2 sensor on order.