VR6 high dipping idle with voltage drop

[Golf Houso]

I've been having a small problem with my VR6, where it occasionally develops a higher idle (780-800rpm) which rises and falls i.e. thrumm .... thrumm .... thrum and with that i have noticed that the voltage on seems to be dropping as the rpm drops as I can see from the dash and tacho's which dip slightly every time it falls.

Anyone have any suggestions to what it could be? I'm getting new leads this week, but I doubt they're related.

Cheers, Branko.

[The_Hawk]

Is it when you have the indicators on... and is in time?


Mine does that when the lights + indicators are on sometimes. The auto elec seems to think it might be like alot of BMW's with a sensitive voltage sensor, basically it senses a drop when the light blinks, so raises the revs, voltage goes up, the lights blinks off, voltage drop so so do revs... repeat...

does that make sense?

Everything seems to work fine and there is no dip in lights if I manually raise the revs so it sounds like he might be onto something.

Personally I think it might also be a battery in need of a good charge that doesn't help the situation too.

[Golf Houso]

Is it when you have the indicators on... and is in time?


Mine does that when the lights + indicators are on sometimes. The auto elec seems to think it might be like alot of BMW's with a sensitive voltage sensor, basically it senses a drop when the light blinks, so raises the revs, voltage goes up, the lights blinks off, voltage drop so so do revs... repeat...

does that make sense?

Everything seems to work fine and there is no dip in lights if I manually raise the revs so it sounds like he might be onto something.

Personally I think it might also be a battery in need of a good charge that doesn't help the situation too.

That does make sense actually Aaron, the battery is new though and I'll have another go at it later when I take it for a drive tomorrow. I honestly thought it was the voltage regulator on the alternator or something...

[MattyT]

800rpm is high idle? Mine sits at 1k no matter what!

[Golf Houso]

800rpm is high idle? Mine sits at 1k no matter what!

What the? Mines on a average idle of 630 and is very stable, except when it misses (new leads on the way) or when that volatge problem occurs.

You must have one seriously loud VR6

[skoota]

i have the same issue with my vr6.
would love to know what's causing it

[william]

600 is a low idle it should be 800 adjust your idle on the throtlle body there an adjustable 13m nut crack it and wind the tread up. If that doesnt fix it i would say you have a misfire most likely a dodgie lead bring it down il have a look at it

[Golf Houso]

600 is a low idle it should be 800 adjust your idle on the throtlle body there an adjustable 13m nut crack it and wind the tread up. If that doesnt fix it i would say you have a misfire most likely a dodgie lead bring it down il have a look at it

Oh righto, I'll have a look at it. I've got 3 dodgy leads, they're all going lol. Thanks for the offer though William !

[william]

Oh righto, I'll have a look at it. I've got 3 dodgy leads, they're all going lol. Thanks for the offer though William !

il have a look in the garage i may have some old black leads they would work better than your current ones.. new bremi ones from south yarra in alexandria are 200 odd have a look on the net also

[Golf Houso]

Ah ok, I've ordered some 10.3mm leads from the UK, they made them up last week, they were 135 posted, I'm pretty happy I'll see how they go anyway.

[william]

Ah ok, I've ordered some 10.3mm leads from the UK, they made them up last week, they were 135 posted, I'm pretty happy I'll see how they go anyway.

do the thicker leads fit the original slots in the plastic?? also be careful when you fit them make sure you spray the plastic with lube spray or wd40 bc the plastic cuts the insulation.

[Golf Houso]

do the thicker leads fit the original slots in the plastic?? also be careful when you fit them make sure you spray the plastic with lube spray or wd40 bc the plastic cuts the insulation.

Yeah they fit, I've seen pictures of them and they're apparently as far as you can go without causing problems, basically the same diameter and style as the Schimmel performance leads. Worst case I'll modfiy the brackets that hold the leads down on top of the motor...

Good point about the WD40 as well, I'll definately do that when I put them in!

[william]

[QUOTE=Golf Houso;312863]Yeah they fit, I've seen pictures of them and they're apparently as far as you can go without causing problems, basically the same diameter and style as the Schimmel performance leads. Worst case I'll modfiy the brackets that hold the leads down on top of the motor...

Good point about the WD40 as well, I'll definately do that when I put them


i sorta roll them in so they dont cut the insulation, also have you got the link for the leads you got??

[Golf Houso]

These, good for the money I think...

http://cgi.ebay.co.uk/Volkswagen-VR6-10mm-4-Core-Race-Quality-Lead-Sets_W0QQitemZ350188584584QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item350188584584&_trksid=p3286.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

[Tim]

600 is a low idle it should be 800 adjust your idle on the throtlle body there an adjustable 13m nut crack it and wind the tread up. If that doesnt fix it i would say you have a misfire most likely a dodgie lead bring it down il have a look at it

The standard idle speed on a VR6 after the innitial warmup is 650 RPM. The idle speed is controlled via the ECU.
Is it possible your car is revving the car up because its coming close to stalling? My vr6 used to randomly have a problem when you pulled up at the lights where the revs would drop to maybe 400 then all of a sudden the ECU would dial in a heap more revs. then it would fall too low again. And bounce back up. Would keep on doing that till i touched the throttle.

The problem went away after I installed the schrick intake manifold. I figured it must have been the ISV dampener causing the issue as that was the only part not used in the schrick install. Not sure if your later model VR6 has one of those though.