91 BMW 318is problem

[timmy.chisholm]

I have a 91 BMW 318is E30 M42, I've been trying to fix this car up myself and learn at the same time, I'm no expert, but anyways, the problem of the car is that the motor will sort of kick out on me when i'm driving. I get a sudden loss of power/RPMs and then it'll kick right back up, unless the loss of power makes the car stall, which can get pretty embarrassing. In 4rth or 5th it drive perfect with no problem... it also has a very low idle speed, and goes from 500 rpms(which makes the whole car shake) to 2000 without me touching the gas.. then right back down to 500, and usually ends up stalling...
I've already replaced the spark plugs and the air filter and checked the spark plug wires but they seem fine according to an ohmsmeter
any help would be greatly appreciated....

also to add in, whenever it kicks out the engine light turns on and goes right back off... if that means anything

Timmy Chisholm

[Blackice]

Try turning the ignition to on, but do not start the car for a few secs.... Give the fuel pump a chance to pressurize the fuel line. Does that help ? Let me know

Dave

[timmy.chisholm]

Well the good news is that the engine kicking out and the idling problems are gone, but the bad news is i'm currently only running three cylinders... the spark is fine... but if you disconnect the electric coil to the 4rth cylinder, the motor doesn't react to it at all... but if you take the spark plug out of the motor and have it connected while it runs, it will still spark... maybe fuel injector or stuck valve problem??? an ideas on this? also when the cylinder failed the exhaust system had some problems, including muffler is now completely distroyed and the bracket holding together the muffler to the rest of the pipe broke... but that might have been an isolated accident...

sorry blackice but i never got to actually try your recommendation but thanks for the reply

[timmy.chisholm]

I also want to add that the car has lost most of its power (which i know is a given) but also fuel consumption has more than doubled (which might give something away to what it was) personally, this is the first time i lost a cylinder before so i don't know too much about it...

Thanks,
Tim

[mirek]

try running a compression test

[timmy.chisholm]

can anyone tell me how i'd go about doing that? or a link to instructions...

[timmy.chisholm]

Okay i found out what a compression test was and the local garage will do it for 40 dollars... unfortunately the car currently has no working brakes... it needs a new brake line and to be bled and such... so basically i can't get it there safely. And i'm not putting money into anything else until i figure out what's wrong with the motor, so I've decided to take the head off and see whats going on in there and hopefully i'll find out what's wrong, if i can't figure out whats wrong i'll get some help...