Author Topic: Cleaning the ISV  (Read 11498 times)

Offline Goops

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Cleaning the ISV
« on: 10 January 2009, 18:00 »
Hey Peeps,

Been having issues recently when driving...
If i pivot heavily on the accelerator/throttle, the rev meter seems to bounce up and i loose power.
Also I set the idle to approx 900/100 rpm when the car is warm but after a journey it seems to idle higher everytime..  :huh:

I plan to clean the idle screw and throttle bits tommorow but pulled out the ISV unit as well..




I am assuming cleaning this can help?
I have some carb/injector cleaner spray lying around, is this sufficient?
Shall i just spray into the 2 inlets and leave overnight?
Not sure how to clean this baby from the inside!

Thanks in advance  :smiley:

Offline raks.2008

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Re: Cleaning the ISV
« Reply #1 on: 10 January 2009, 19:40 »
Cleaning the ISV with Carb cleaner does work sometimes but often if totally buggered then it will not work. The best way to check if it is working is while the car is idling pull off the black hose that leads from it going to the air intake. The car should stall if it is working...


Offline Conker

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Re: Cleaning the ISV
« Reply #2 on: 11 January 2009, 10:58 »
Cleaning the ISV with Carb cleaner does work sometimes but often if totally buggered then it will not work. The best way to check if it is working is while the car is idling pull off the black hose that leads from it going to the air intake. The car should stall if it is working...




Another test is to turn the ignition on but not start the engine - The ISV should be making tiny tingly vibrations (ooo err!) if you touch it.


I wouldn't leave carb cleaner in the ISV overnight as thats a bit too harsh IMO. I use WD40, spray a load in one of the holes, cover it with my thumb and shake it a bit. Empty and repeat until the WD40 runs out clear. Repeat for the other hole.

I think someone on here has buggered up an ISV by soaking it in too harsh a cleaner.

Remember that after cleaning your ISV, the idle will not be perfect for a little while (say a few mins of engine running) until its dried out etc.


Offline Goops

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Re: Cleaning the ISV
« Reply #3 on: 16 January 2009, 22:27 »
Thanks Peeps!
After a week in bed battling the damn flu, i got outside to the beast! :smiley:

The cleaned ISV in, and went for a quick drive, still got the power loss/over rev issue!  :huh:
I am going to try new spark plugs and HT Leads tommorow..
Anyone used leads from GSF before?? or should i go with dealer item?

Offline Conker

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Re: Cleaning the ISV
« Reply #4 on: 16 January 2009, 23:04 »
Anyone used leads from GSF before?? or should i go with dealer item?

Dealer leads are megabucks as you have to buy them separately! (When I last checked anyway) I bought mine from ECP and there okay (had one faulty set). Beru leads are supposed to be good from http://www.vwspares.co.uk/


Offline Goops

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Re: Cleaning the ISV
« Reply #5 on: 17 January 2009, 23:55 »
Cheers Conker,
Rang the dealer - £109 for a set of leads  :laugh:
Got a set with spark plugs from GSF, car seems to run cleaner but there is still a slight misfire/power loss..
Rotor arm and dizzie cap next week i guess!

Offline dTEA

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Re: Cleaning the ISV
« Reply #6 on: 23 January 2009, 18:15 »
mine got cleaned with some fuel left to soak...thats what i got told was the best  :huh: dunno if that was right :undecided:

Edition 30 / T5 T32 Kombi

Offline Goops

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Re: Cleaning the ISV - "Misfire" UPDATE
« Reply #7 on: 14 February 2009, 22:13 »
Just an update,

Did the dizzy cap and rotor arm in the morning.
The rotor arm was glued on and had to gently be broken off, not sure if an adhesive should be used on the new one?
 :undecided:

Anyway, story so far:

- Cleaned ISV
- New Sparks
- New Ignition Leads
- Dizzy Cap
- Rotor arm

Car was still misfiring higher in the rev range, so went to a local mechanic to get the timing done..
Followed the kr timing guide and did it from gearbox end with the 6BTDC lined up with timing light..
Took her for a spin and was pinking slightly, adjusted dizzy to get about 5 degrees instead of 6, runs better but still got the misfire. :sad:
Gave up and asked the mechanic to take her for a spin... after 2 mins he said it is definitely the clutch that is gone/on way out and is slipping on the higher power curves  :cry:

This is not a job i could possibly do on my own so it has to be dropped to a garage.
Anyone know what a fair price for the labour involved would be??

Ta,

Despondent G


Offline OakeyDoak16v

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Re: Cleaning the ISV
« Reply #8 on: 15 February 2009, 00:55 »
Sorry to hear that. It's just one thing after another with these cars. I just had to spend £60 on a bonnet latch today because the old one gave up on Thursday.
Sorry i have no idea about labour costs, if i had to hazard a guess i would say your looking at 4 hrs work possibly, at £45 per hour (thats what my garage charges)
Good luck! :smiley:

Offline Conker

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Re: Cleaning the ISV - "Misfire" UPDATE
« Reply #9 on: 15 February 2009, 15:14 »
...after 2 mins he said it is definitely the clutch that is gone/on way out and is slipping on the higher power curves.


Do you really trust/respect the mechanic?  I'm no expert on clutches, but I would have thought a knackered clutch would feel very different to a miss-fire??