My girlfriend just bought a 1985 528e with 171,000 miles on it. It seems to be in great shape and I think she got a pretty good deal since just about all the maintinence is up to date (recipt for timing belt 6 months ago). When she got it it was parked at my house for a few days while she got it registered and insurred. In that time, the battery died (I think the glove box was open and the light was on) so I tried to jump it. It was dark and I didn't realize that this car had the wire colors backwards (red = ground, black = positive) so I tried to jump it like that. Need less to say it didn't work so I just put in a new battery (wired correctly after looking in the Bently manual). Everything seems to be ok except that now it takes a few cranks to start although it does start and run well. Since it is new to me, this might have been happening before but I don't think so. I am worried I wrecked the ECU or something else. Any ideas? Thanks.

if it starts and runs good, you probably didnt ruin any of the components. I would check for vaccum leaks, perhaps the cold start injector as well. Should be some info about that in the bentley i think.

-Jeff

if it starts and runs good, you probably didnt ruin any of the components. I would check for vaccum leaks, perhaps the cold start injector as well. Should be some info about that in the bentley i think.

-Jeff

Thanks Jeff I will try and look for vacuum leaks. I am not sure about the cold start injector though since it seems to start this way reguardless of what temperature the car is at. Thanks again.

If your ecu still thinks its cold, like a faulty temp sensor, then the cold start would run. When my temp sensor went out, the car barely started, and when it did, it revved @2k then with some peddle applied it would die.

If your ecu still thinks its cold, like a faulty temp sensor, then the cold start would run. When my temp sensor went out, the car barely started, and when it did, it revved @2k then with some peddle applied it would die.

How did you diagnose that the temp sensor was bad? Is there an easy way or did you just replace it cause it is not that expensive?

i just replaced it. It was a hunch. I have an extra brand new one I just recieved by mistake with my last order. Let me know, its for an 86 535i m30.

i just replaced it. It was a hunch. I have an extra brand new one I just recieved by mistake with my last order. Let me know, its for an 86 535i m30.

Ok I can try that too. If that is all I have to do after pulling such a stuipid move I got off lucky.

It's a 528e though so it has an M20 motor in it so I don't think your extra would fit. Thanks for the offer though. I appreciate the help. Will keep posting as I go.

I just got a phone call from her and she says now she smells gas but only when the windows are open. Is it possible that one of the cylinders isn't firing?

it could be a bad afm. does the acceleration have flat spots?

it could be a bad afm. does the acceleration have flat spots?

Not really. It doesn't have much power but it is pretty smooth.

wait, so your saying the car runs well, it just takes a few extra cranks to start. thats pretty typical for an older e28. Mine takes like 5 or 8 cranks sometimes.