Rough engine

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Sep 23, 2005 | 08:54 AM

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Rough engine

Been searching through the archives for an awnser to a couple of my questions but havent exactly found what i am looking for. The engine is running rough slight noise from back passenger side to back middle just sounds off no rattle or anything. Car was disconnected from the battery while i put in subs/amp and after i reconnected it it hasnt run well since. I was wondering if it takes a certain amount of driving for the ECU to remap how it should be running ie(timing, Air/fuel mix)I have cleaned the MAF no change thinking of doing the ECT sensor which i got a CEL for 2 months ago but never returned and maybe a TB clean. Idle when first start is about 1200 then settles when warm down at 800rpm. OBDII says MAF readings in 2nd gear max out at about 65g/s at 6krpm. Any response would be appriciated.

Thanks

Sep 23, 2005 | 09:00 AM

Solaris

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From: NC

Did you do a throttle body alignment? After battery disconnects, you're supposed to...

leave the key in the on position for about a minute before starting the car.

Sep 23, 2005 | 09:38 AM

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Yes

Sep 23, 2005 | 09:59 AM

BigEd

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You need to do VAG TBA. The batt disconnect method doesn't always work. Get a hold of

someone with a VAG-COM. The procedure is short and simple.

Sep 23, 2005 | 10:11 AM

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Would this be causing the MAF readings to be so low?

Sep 23, 2005 | 10:38 AM

BigEd

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I don't know. But the fact is that the problem appeared after batt disconnect ...

And the first thing you do after batt re-connect is VAG TBA in order to sync ECU and TB.

Sep 23, 2005 | 01:36 PM

Ray993

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Three ideas

1) Throw in a can of Techron fuel cleaner.
2) Then fill up the tank with Sunoco 93.
3) Then take it out on a back road and give it a nice "Italian tune-up" for an hour or so.

Can't help with the MAF; I haven't played with OBDII output. However, if you haven't had an engine CEL come on would guess there's nothing physically wrong with the engine. I DO frequently do the above tune-up on both the 95 Porsche (91K miles) and 98 A4 (102K miles) and notice either an improvement in smoothness/performance or else (at a mininimum) no engine degradation.