IDLE PROBLEM - DRIVING ME CRAZY

[imranp 0]

I have a 94 2.0l 16v - i bought it from a guy who assured me it was a slight idle problem. i have always wanted a rado having driven GTI's and i think the adrenaline got the better of me, anyway to cut a long story short i bought it with the problem thinking i will be able to fix it but as the days turn into weeks and weeks to months i am beginning to loose patience :censored: and just want to get shot of it cos the wife keeps chewing my ear off about spending money on a car.

 

I have seen plenty of threads on here that mention this problem. i have checked the hoses for air leaks cleaned the throttle body the ISV looks a few months old and changed the temp sensor.

 

when i bought it, she was hunting/kangeroing but now it has started to rev between 1000-15000. i cant seem to locate the problem and any help would be appreciative. it also appears to be burning more fuel could that be because it is idling higher then it should??

 

i am based in Birmingham if anyone local can also help. i have enlisted the help of my trusted mate who works on volkswagen's but we seem to have hit a giant idling wall.

 

imran

[Jim 2]

Have you outright replaced the idle valve? Well worth hunting down a working spare to rule it out. My valver had endless idling problems and I cleaned the ISV out several times and it didn't make a shred of difference.. changed the idle valve and its been great ever since (3 years ago!).

 

A new one is prohibitively expensive (around £200 I think!) but second hand ones crop up regularly for anything from £10-£50. A VR6 one will also fit....

 

e.g. This Slightly Pricey eBay Item

 

:)

 

Could also be lambda related possibly. Does the car run ok for the first 5 minutes or so when cold, and then get lumpy / rough?

[davidwort 0]

also, consider getting it to an MOT tester and get them to check the CO and lambda values, they'll do a part throttle lambda test to see if the lambda value wavers around, sure sign the sensor is shot or dodgy. 2.0 16v engines can have really bad idle problems with dodgy lambda sensors. non VW pattern ones can be as bad as worn out genuine VW ones, NGK or Bosch ones should be OK.

[mimjed 0]

Video of idle would be helpful. Mine was hunting quickly, turned out to be inlet mani gasket.

 

Was found by a smoke test, but prob cheaper to just replace the gasket if youre spanner friendly

[krnau 0]

quick one, have you tried to pull the accelerator pedal towards you? This may look a bit of nonesense but my car used to have this issue and that was (one of) the faults.

 

does the isv microswitch (located in the TB) get in contact with the throttle body when it's closed? If not, try to untighten the accelerator cable; if still not, try to adjust the switch's mount so that it gets in contact with the throttle body. You'll understand this when you see the switch.

 

 

Hope it helps :wave:

[imranp 0]

thanks for the advice lads i will look into the suggestions as soon as i get a chance i have some videos of the idle but it wont let me any ideas what format they have to be in. just so you know i tried the accelerator pedal thing that was suggested that hasnt worked. i have also changed the inlet manifolds but no luck.

[imranp 0]

does anyone know if this hunting can cause the car to run rich. i filled up 30quid and the car has dun 130 miles and i need to fill it up again. thats 22mpg.

[krnau 0]

what about the microswitch? did you find it?

[easypops 8]

Is the 5th injector(cold start) plugged in........mine was faulty and on constant.........unplugged it and it was never a problem after that

 

more reading for you on idle issues

viewtopic.php?f=1&t=95553&hilit=2.0+16v+idle

viewtopic.php?f=1&t=95205&hilit=2.0+16v+idle

 

lots of links inside the threads :D

[imranp 0]

i havent located the microswitch. havent had a chance really is it in the actuall tb or on the out side by the accelerator cable? also i havent looked at the fifth injector but will do that tonight once im done working.

 

thanks again for your comments

[krnau 0]

i havent located the microswitch. havent had a chance really is it in the actuall tb or on the out side by the accelerator cable? also i havent looked at the fifth injector but will do that tonight once im done working.

 

thanks again for your comments

the switch is on the tb itself, in the face that looks towards the radiator

 

I would also try disconnecting the 5th injector electrical connector, and if the problem's still there, I'd take it out when the car is hot and look for any leaking issues

[imranp 0]

so the fifth injector thing didnt work, but i have a day off wednesday im guna meet up with a mate and try and locate the problem, will post again on wednesday

[imranp 0]

so iv been gone a while trying to find the fault my mate found a working 2.0l 16v and switched some parts over he switched the i s v valve,ecu no joy then changed the metering head and injectors no luck. the big rubber boot had got split in changed that made it better but still got the problem the throttle body

needs changing but im begining to think that its lamba related and just to change the sensor and take it from there. i changed the gaskets on the inlet but still no luck but there is a slight blow coming from the inlet mani its an aftermarket one fitted by awesomegti. any ideas cos im all out of them?

thanks lads

[Jim 2]

Have you not swapped the throttle body yet? It's a real doddle and if you've got a donor 16v to take it from it really isn't a difficult job to swap them out :)

[imranp 0]

the throttle body off the donor didnt do it but it cud be cos its off an older 16 v the guy who owns the donor car has a throttle body feom a later model thati want to try first that he needs to find if this doesnt do it on to the more expensive job i.e lamba sensor.

 

thanks again for all ur input

[imranp 0]

So i have finally solved the problem :clap: it was a wiring loom problem, it was missing to live connections from the metering head to the ECU. I have had the wiring loom replaced.

 

on my travels in repairing the idle problem I also found that the engine was guzzling oil like an alcoholic. i found the head gasket was on its way out had the engine replaced by this real cool guy in brum. He fabricated a custom exhaust for me and now she purrs like a cat. loving it.

 

thanks for all you comments.