Spooky Failure

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paultv
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Location: Auf dem Schnee: Germany

Fri Mar 11, 2022 4:09 pm

Hacking back down the autobahn enjoying some spirited driving last night - when there was a sudden but very short power loss - likethe engine was turned off - definite electrical problem -bugger I thought, 10km from home - I hope I make it - this stuttering repeated itself several times - seemed to be getting worse - oh oh - time for the ADAC - but no, I made it home with frequent sudden death events, stalled at some local lights, but started again. Tacho was dropping to zero each time so definitely electrical.

Started the car this morning, it ran for 5 seconds, made a really spooky sound and died.

Bit of time later today - car started fine, ran for a while - same kinda screech sound and stopped dead. Checked the main ECU relay - replaced with a spare - same issue.

So I kept starting the car and listening for the strange death strangle sound - and noticed eventually that the ICV was making extra odd little noises with the ignition on. Pulled the cable and whilst the idle was all over the place the engine was clearly stable. Lucky me I have a spare ICV, plugged that in without actually installing it and the car ran fine - pulling the plug and re connecting the old ICV caused instant death.

So problem solved, I guess there's a motor short in the ICV which draws a load of juice and strangles the ECU - certainly a new one on me, I wasn't aware that this little thing was capable of leaving you stranded -obviously pulling the ICV plug will save your life and you can drive all day, but with a lousy tickover or crazy hunting engine - but only if you know to look at this as well as the main relay and the CPS as other possible sources of hard shoulder hell.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
tha881
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Sat Mar 12, 2022 5:45 pm

Are they both oem ICV's? Maybe the faulty one has reached the end. Have you tried one of the replacements from Lowe?
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paultv
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Sun Mar 13, 2022 7:07 am

Yeah...both oem...the failed one is the original from the car...I tested the pins and I get a short if I turn the activator inside...so its well stuffed....might try to open it to see what's happened to it.

Useful link to the Lowe site.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
tha881
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Sun Mar 13, 2022 9:30 am

I didnt realise an icv could leave you stranded like that. I find they need a flush through with carb cleaner quite regularly. I have two Lowe ones here as the first one they sent the idle kept fluctuating, so they sent a replacement and that did the same. I've stuck to just cleaning the oem one every couple of months.

It would be great to see if you could open up and service the faulty one yourself
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