Air flow sensor issue?

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mk2mark
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Air flow sensor issue?

Post by mk2mark »

Hi guys,

I have a weird intermittent issue on the car (86 635). The car randomly started bucking and running very poorly. I initially thought it was fuel related since there was an engine bay leak (that's now fixed), I replaced the fuel pump and filter - the car ran ok for a little bit and is back to running poorly again.

One thing that seems to be new is there is a light on the dash that flashes (see attachment). My question is am I right in thinking this is the air flow sensor? If so is it something that's possible to repair/replace easily? what other things should I be checking?

Thanks guys.
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hornhospital
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Re: Air flow sensor issue?

Post by hornhospital »

I'm guessing you have an automatic transmission, because that is the warning light for a transmission fault.
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'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
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mk2mark
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Re: Air flow sensor issue?

Post by mk2mark »

Interesting. The used to be an automatic transmission, I swapped in a 5 speed. Maybe the light is not related?
kronus
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Re: Air flow sensor issue?

Post by kronus »

if this car previously had the selectable mode transmission (4HP22EH), there is a whole transmission control unit that is probably partially unplugged, confused and scared, somewhere under your dashboard.
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mk2mark
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Re: Air flow sensor issue?

Post by mk2mark »

I should add that the car has been running fine previously to this.
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86_6series
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Re: Air flow sensor issue?

Post by 86_6series »

I would start with this to zero in to find the problem.

https://hpsimotorsports.com/blogs/tech- ... ch-article
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mk2mark
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Re: Air flow sensor issue?

Post by mk2mark »

Thank you, that's a great guide.
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