1996 vw golf vr6 lumpy idling

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Wed 24 Nov 2004 20:23
1996 vw golf vr6 lumpy idling - ammo
ive recently renewed the brake servo vacume pipe, HT leads, air intake pipe, airfilter & airfilter housing on the vehicle. Ive noticed the vehicle doesnt idle as smoothly as it used too. Ive have thorougly checked over the work many times to make sure everything is tight and secure. I cant see where i have gone wrong. Someone did mention whether i had left the engine running while any of the parts i.e. airfilter/air intake were removed & replaced. As far as i can remmeber, the engine was accidently left running for approx 5mins without the airfilter & air intake connected. There is no spluttering or the rev needle moving erraticly, but there is a frequent "bump...bump" sound when the engine idles. Any help appreciated.
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Thu 25 Nov 2004 09:42
1996 vw golf vr6 lumpy idling - DP
This might sound daft, but did you disconnect the battery? How long have you run the car for since, and have you driven it?

I remember disconnecting the battery on my old 306 and it ran like a bag of nails afterwards. The KAM (Keep Alive Memory) settings in the ECU get wiped when the battery is disconnected and the system resorts to its default settings until it "re-learns". To do this you need to take the car for a good 15-20 minute run with a mixture of stop/start, high speed and steady speed driving.

I only mention this because I was horrified at how the 306 ran. After this varied drive, it was fine.

The bump bump could be something rattling if the engine idle speed is too low or erratic. Does it disappear if you open the throttle at all?
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Thu 25 Nov 2004 19:19
1996 vw golf vr6 lumpy idling - ammo

i did at one point disconnect the battery. Its been 1 week now since ive had this "slight" lumpy idling. I drive to work and back everyday (15 miles). I was advised to carry out the following procedures if i experienced lumpy idling after fitting new parts:

-disconnect battery for 10mins & reconnect.
- turn on ignition, but do not start the engine.
(a buzzing sound will be heard for 30 seconds near the air intake. This is the ecu adjusting for new settings).
-once buzzing sound has gone, turn off ignition completly & start up engine.

This really made no difference.

i usually get the bunp bump sound, after ive had the throttle fully open.

Ive also noticed the engine seems to idle at 800rpm instead of 900 rpm.

The lumpy idling is present when i start the engine from cold but becomes obvious to me at normal operating temperatures.



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Thu 25 Nov 2004 19:20
1996 vw golf vr6 lumpy idling - ammo

sorry!
The lumpy idling is not present when i start the engine from cold but becomes obvious to me at normal operating temperatures.
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