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redwoodkp

16v idle problems

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I know its a well talked about topic but having searched i cant find anything to solve my problem.

 

It all started friday night when i pulled up to my drive after 20 mins tops driving home. Idle just fell to 500rpm no noises or anything just dropped. Started it up the following morning and it ticked over sweet as a nut, even let me move it off drive with no problems. Half an hour later i came to go out, started her up with no apparent issues and went to reverse off the drive again. As soon as i got the bite on the clutch the car stalled, started her up again with few extra revs and stalled, started again and just sat at 500rpm as if it was in default mode just enough to tick over on autopilot or something. I left it running for a couple of mins at 500rpm and unplugged the idle valve it never changed a thing. Could this be the idle valve then?? Left the car all day and yesterday and tried again this morning having changed the idle valve incase that was the problem. Same again happened although i left the car running on start up five mins and then gave it some revs. As soon as it dropped from the first rev it went to 500rpm again.

 

Any ideas?? Is it the idle valve or idle screw??

 

Many Thanks

Kieran

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if its been running fine with the idle screw as is i wouldnt touch it. have a look round the engine bay and check for any air leaks, to test if its the isv just unplug it and run it for a day without it plugged in see what happens. is the performance of the car any different or is it literally its idle?

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if its been running fine with the idle screw as is i wouldnt touch it. have a look round the engine bay and check for any air leaks, to test if its the isv just unplug it and run it for a day without it plugged in see what happens. is the performance of the car any different or is it literally its idle?

 

Car runs like a dream normally no problems. Even on start up on the coldest of days it needs no throttle help to get going just fires straight up to 1500rpm and settles when warm to just under 1000rpm. Thats why im bit confused to whats going on. Will check for air leaks but i renewwd most of the connections a while back to make sure there shouldn't be any problems in that department. Only other thing to check is the air filter (K&N) but wouldn't have thought that this would cause such a big difference if not workign properly.

 

Gonna get another ISV to try and see if it makes a difference. The spare i had isnt exactly trusted and is 037 906 457 C. I looked on vagcat and the oem is 037 906 457 D.

 

Cheers

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it shouldn't idle at 1500 when cold and only drop to 1K when warm, it should pretty much idle at 1K all the time if everything is in order, perhaps someting else is dodgy, thermotime switch, warm up regulator etc. I can't remember off the top of my head, but the golf and passat haynes manual that covers the 16v engines describes the basic checks for these components.

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When i put idles at 1500rpm, i meant it fires up on a cold day to there but pretty quickly settles to 1000rpm. It never runs at that high otherwise i would definetly being tearing my hair out!! Sorry for the confusion.

 

Cheers for the reply david. I've got a golf/jetta haynes that covers the 16v kr engine to a certain degree will have a look through the morrow to guide me. Will definetly be changing the ISV for the right one just to make sure its not that.

 

When the ignition is on though are you meant to hear the ISv buzz when your sat in the car with the doors shut and bonnet down or should you only be able to hear it buzz when your under the bonnet?? Just thinking if its anything like the fuel pump the louder it gets is a warning to its on its way out??

 

Many Thanks will keep you all posted

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The items that I had to address to solve this problem:

 

1) Replacement fuel metering head (2nd hand) as the car wouldn't start at all (or cut out straight after starting)

2) Cleaned the ISV with carb cleaner as it had a really rough idle

3) Replaced a fuel injector as the car wouldn't start if it was already warm (weeping injector was flooding the engine)

4) Engine re-tune as it would cut out after about 15 minutes of driving and not restart until it had cooled down (GCS charged me £45 for this)

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...

When the ignition is on though are you meant to hear the ISv buzz when your sat in the car with the doors shut and bonnet down or should you only be able to hear it buzz when your under the bonnet?? ...

 

nope :lol: it's just a little electro-magnet, if you take it off the car and short it to the battery it should click shut with 12V applied, but that doesn't mean it isn't sticking in normal operation a bit.

 

When mine went dodgy it would tend to hang on to revs a bit high when idling in traffic, sometimes a blip of the throttle would bring it back to 1K, they do eventually go beyond cleaning it seems.

At the moment I have a mk3 one on there, not quite the right fit for the pipework on the KR 1.8, but close enough and it controls the idle just fine.

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Right i've tried three different idle valves now to determine whether thats the problem. Only one of them actually starts the car now but still only runs at 500rpm just about ticking over. I adjusted the idle screw so the car was idling at 1000rpm then gave it a few revs and it settled back down to 1000rpm but wasn't very smooth like a few days ago. I decided to unplug the valve to see if it changed the running of the car but it stayed exactly the same!!

 

This now means potentially all three of the isv's i have tried could all be shot or is it an electrical problem to the isv??

 

Just done a bit more searching and boostmonkey has a post that mentions the relay no.42 and the idle control unit?? Worth changing both of these??

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