Eric NY

Posting on "the bottom" of yesterdays post to incorrect forum!

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Gents,

Had bought, rehabbed and sold ($1k in parts) a clean 96 A6 Avant in the fall. Was sold locally to a guy i know...

He just called and they're having a intermittent start issue. Occasionally car won't start (when hot), but if allowed to sit will start after a while. Tonight they had to let it sit for 45 minutes before it would fire.

Going to run VAG Com tomorrow morning to and see if that shows any codes...

don't know if it's fuel or ignition related, hopefully able to narrow it down in the morning once he gets here!

Any BTDT's? Going to surf around and see what i can find, but figured i'd ask here first.///

Todays update!

Looked at car a few moments ago. No CEL, no codes stored (VAGCOM). Fuel pump is/does run. Car sat for a while and didn't start, but immediatly tried again and it started right up. Couldn't duplicate the problem, of course!!!

Have had some replies indicating cam position sensor may be the culprit. But, wouldn't that store a fault?

don't have any manuals, Bentley or otherwise, and haven't been able to find any info on troubleshooting the CPS on the web. Possible for someone to scan the appropriate pages, or give me the procedure? Assuming it's a ohm check, but need to know the pins/resistance values. (If this was a type 44 it would have already been fixed! haha)

Thanks,
Eric

DaveInSaltLake

sure sounds like a cam position sensor. I hear they cause intermittent no-start problems when going bad. Most of the bad ones I've seen were cracked at the electrical connector. check your email.

Squirt-Tortuga

I found that they tend to get buildup of metal shavings on the inside of the sensor. Blowing them out with compressed air is the typical solution.

As a side note, almost every one that I have seen has had a broken plastic clip. It doesn't really affect their function, as long as the wires aren't stressed/broken because of it.

DaveInSaltLake

Interesting, I'll have to try that. Any idea where the metal shavings come from?

austinado16

Nice tip, thanks!

RS6er

I had that on my 95 A6Q Avant. Eventually, I couldn't get it started at all. Sensor WAS the problem.

Eric NY

Thanks for the input gentlemen! Will have the car back here in a couple of days, or sooner if it dies completely. Will post final "results" to the forum!

Thanks, Eric

Squirt-Tortuga

I have never seen obvious gall marks or scraping. My guess would be that "timing wheel" that triggers the sensor is somehow deflected within the housing and contacts the sensor itself.