running rough

[edward]

Hey Guys,

I have not posted in a while because my car has been behaving. This new problem is a bit of a puzzlement.

Car starts an idles fine, still idles if you put on ac, or put transmission in drive.
When I touch the gas then it bogs and dies, and it will die sitting at a light.

I am trying to go through all the tests in Bentleys, I don,t think it is the idle speed control because it seems to idle ok. Buy the way where is this located.

My throttle switch tests out for resistance, but I dont get th 5v on the correct lead, I get it on the other 2. Could this switch be causing my problem?

Lastly, Bentleys says my mas should have a hot wire and I cannot see a wire of any sort. Looks more like a flat blade.

No engine service light on, and I cannot produce any codes with the stomp
test. My car is a 1993 525it. Thanks, Edward

[whiskychaser]

don,t think it is the idle speed control because it seems to idle ok. Buy the way where is this located.
Its underneath the inlet manifold close to the block
My throttle switch tests out for resistance, but I dont get th 5v on the correct lead, I get it on the other 2. Could this switch be causing my problem? It pouring with rain or I would check mine for you. But I'm pretty sure mine is the same
Bentleys says my mas should have a hot wire and I cannot see a wire of any sort. With the air filter box off, you should be able to see up inside the MAS. When you stop the engine running, the wire glows for a few seconds to clean it. That helps you check its not broken:-) Its a very fine wire, probably about as thick as a 5 amp house fuse wire. Yeah I know they dont use them these days but if you are my age you will remember them:D
You arent getting any codes so my guess is its a 'physical' thing - maybe low fuel pressure?

[edward]

Found the problem by doing a search on this site. It was the brown ring of death on the spark plugs. Changed the plugs and the spark plug boots and now it runs fine.

Thanks, Edward

[Dave M]

Found the problem by doing a search on this site. It was the brown ring of death on the spark plugs. Changed the plugs and the spark plug boots and now it runs fine.

Thanks, Edward

For future reference, the 'brown ring of death' was an over-reaction and relatively normal behavior for plugs. You likely replaced a bad coil boot (shorting), which solved the problem.

Dave