lbs_ft

Here's the issue:

Car is a 92 BMW 5 series with a 94 M50 motor swap.
Aftermarket cams (unknown), Bavarian Auto Works Chip

The car starts and runs fine, but as it warms up it begins to lope. We've run through tons of possibilities and eliminated vacuum leaks, fuel problems, and electrical issues.

We've pretty much done all that we can do, what we need now is to hook it up to a computer to find the issue.

I've researched local businesses, but they can charge upwards of $200 just to hook it up.

Anyone know anybody with the ability to tune this car or to let me use their diagnostic system?

Any questions, just ask

Thanks

MissmyE30

do you have VANOS? if so the seals? check bimmerforums or e46fanatics, i'm sure somebody is nearby and can pull codes if it's throwing any...

lbs_ft

damn, didn't even think of that.

think that could be it?

MissmyE30

i think so. i'm new to all the bmw computer controlled crap. my last engine was an M20 which was an absolute delight to work on. i think vanos seals might cause some idling/driveability issues but i'm not totally sure. you could search on bf.c or e46fanatics and there's probably a DIY on vanos seal replacement. they might shed some light on the symptoms they were having..good luck!

lbs_ft

yeah i'll get on bimmerforums or something and take a look around.

i found this site: http://www.beisansystems.com/procedu..._procedure.htm

thanks for all your help man

elements018

are there actually any check engine light codes?

lbs_ft

the car runs fine without any codes, but when the loping starts, the 'check engine' light comes on

i have an obd2 code reader, but not an obd1, thats why i was asking if someone had a computer to hook up, so i don't know the exact code

i'm taking a look at the vanos seals tonight though, more updates as they come.

AE - Chris

the regular m50 didnt have vanos. the m50tu had a single vanos. sometimes i have seen failing vanos units do what u describe and wont set a light. as the oil heats up it will leak by the vanos seals. I will look in a few to see if my scanner will go back that far.

Fabrik8

Is there a service check connector that can be jumped to flash the codes out on the check engine light? Many/most OBD1 cars have that feature, I'm not that familiar with BMW troubleshooting though.

MissmyE30

Hmmm. You say it only shows up when the engine is warm. Shot in the dark here but what about your O2 sensors? I ask bc the ecu ignores the O2 sensor signal until the engine is warm so if they're bad they'd be sending a bad signal to the ecu for the fuel mixture and it would only happen when the engine has warmed up. Worth a quick check if you're handy w a multimeter. Unfortunately I have no idea what the proper values would be for your engine. You would need to look online or have a bentley manual handy. Hth.