unstable idling and rough starts

my 99 2.8 has trouble starting once in a while. it feels like it doesn't want to catch and then it idles real high. other times it starts normal but idles high. I can not reproduce it nor can I predict it. I have had 3 or 4 mechanics look at it but they couldn't find anything wrong. when the computer is scanned nothing shows up. Anyone experience this? I'm starting to think its the computer. If it is will a mod chip rectify the issues?

Reply to
jprusso
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have you changed the battery or disconnected it recently? it may need the throttle body re calibrating,

Steve.

Reply to
Steve68s

"jprusso" wrote

Have you tried cleaning the throttle body?

Pete

Reply to
Pete

i have had the throttle body cleaned 3 or four times. this happens very speradically. audi service department says there's nothing wrong.

Reply to
jprusso

j, OK, so you have an Audi.............. If it's a 5k/100/200, I can tell you it can be vacuum leaks, injector leaks, temperature sensor problems, vapour lock, bad gas, fuel pressure problems, check valve leaks, etc. etc. etc. Try:

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Cheers! Steve Sears

1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
Reply to
Steve Sears

"Steve Sears" wrote

Steve,

I guess you didn't catch the beginning of his thread. It looks like he's got a '99 2.8, which I'm guessing would be an A4 or A6.

Cheers,

Pete

Reply to
Pete

A4 2.8 quatro

Reply to
jprusso

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