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Guellermo · Joined: 04 Jul 2004 Posts: 4 Location: Wellton, Arizona

Started a month ago slightly and is becomeing worse. It starts well and misses until fully warmed up. Sometimes longer. After that it runs like a scalded cat. 78,000 miles. The motor has not been professionally tuned since new. Not just sure where to start, although electrics have so far been my only problems. Appreciat any ideas to troubleshoot my problem.

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911's in the rear veiw mirror.

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

Sounds like you are just needing a basic tune up. Plugs, wires distributor cap and rotor for starters. May also try running a good injector cleaner though a tank or two of fuel.

Dennis
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81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

Smoothie · Posted: Sun Jul 04, 2004 1:43 pm Post subject:

Yes, could just need a tune-up like DPW said. If that doesn't fix it,
then I'd suspect a vacuum leak. Could be a split in the rubber boot that connects the air metering unit with the turbo inlet, or any of the many vacuum lines, elbows or the well-hidden line from the turbos' pop-off valve to the bottom of intake manifold runner #1. You'll also have a line from the back of the intake manifold to the DITC box below the dash and behind the radio.

If the tach's needle's flopping around while the missing's occuring, then the problem would be with the 12 pin connector at the DITC box.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Guellermo · Joined: 04 Jul 2004 Posts: 4 Location: Wellton, Arizona

Thanks for the help. Have changed plugs dist cap etc. Must be leak in vacuum line. Sounds like trouble to find!
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911's in the rear veiw mirror.

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

Don't rule out a partially plugged injector. Have you tried the fuel injection cleaner yet? A vacuum leak at the intake to head gasket could cause a miss, BTDT, but a vacuum leak before the throttle body will cause a high idle (small leak) or rough running at lower RPM's (large leak). Have you narrowed the miss down to a certain cylinder?

Dennis
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81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black