ISV for KU engine

Ringmaster · 04-09-21, 04:27 PM

Folks,

My ISV continues to give stalling issues. Cleaning, even with cellulose thinners, only seems to improve the symptoms temporarily. New ones are difficult to find and will be expensive.

There are plenty cheap Chinese valves on the Web, but I found this on fleabay and decided to chance it based on the seller's reviews...It corresponds to OE no: 035133455F.

https://www.ebay.co.uk/itm/254804704...sAAOSwQVFeyMsZ

It looked like the Chinese items but the seller is apparently a German producer. The valve only took 4 days to get here from Germany. I installed it and it works!!!

The only thing is the engine idles at 1150rpm, not 800 rpm. I will need to do some fettling. My engine hasn't been tuned in ages...

mikes2 · 04-09-21, 05:22 PM

It's a bit of a juggling act.

You need to set the idle current to 430 mA.

You also need to adjust your mixture and set the timing.

Changing one impacts the others so takes a while to get it correct.

The rev counter typically over reads slightly so your 1100 on your dash will be closer to 1000. Still on the high side.

It shouldn't stall now if that's your idle.

Ringmaster · 04-09-21, 07:15 PM

Thanks for the advice, MikeS2 ... I'm a novice to the subject....

Ringmaster · 29-09-21, 03:06 PM

My mechanic had a go at fettling the ISV with limited success.

The engine now idles around 1000 rpm and hunts. At least it is not stalling.
Maybe it is a cheap part after all.

He is going to put my old ISV in his cleaning apparatus and see if that can be resurrected.

Ringmaster · 08-06-22, 06:58 PM

Having replaced the rubber bellows on my engine due to the vacuum leak it had, I thought I had cracked my problems. The engine was running much better but still a little rough.

Then it happened again. The car just kept stalling. Swapped in my spare ISV and that seemed to do the trick, but I wasn't happy as I had been here before... The engine still ran a bit rough...

The next time I used the car it stalled within 5 minutes of starting from cold. It re-started well and behaved for the rest of the day. This scenario continued day after day. I had no idea what to do.

I thought I may as well change the dizzy cap and rotor arm while I had my head under the bonnet. The rotor arm turned out to be the wrong part so I just replaced the cap and fired her up.

Stone me, everything seems to be working just fine now....

Duffy3074 · 08-06-22, 07:13 PM

Result!

Baggee · 06-07-22, 03:10 PM

Quote:

Originally Posted by Ringmaster

Having replaced the rubber bellows on my engine due to the vacuum leak it had, I thought I had cracked my problems. The engine was running much better but still a little rough.

Then it happened again. The car just kept stalling. Swapped in my spare ISV and that seemed to do the trick, but I wasn't happy as I had been here before... The engine still ran a bit rough...

The next time I used the car it stalled within 5 minutes of starting from cold. It re-started well and behaved for the rest of the day. This scenario continued day after day. I had no idea what to do.

I thought I may as well change the dizzy cap and rotor arm while I had my head under the bonnet. The rotor arm turned out to be the wrong part so I just replaced the cap and fired her up.

Stone me, everything seems to be working just fine now....

If only things were always so simple in the end but a great result

04-09-21, 05:22 PM	#2
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	It's a bit of a juggling act. You need to set the idle current to 430 mA. You also need to adjust your mixture and set the timing. Changing one impacts the others so takes a while to get it correct. The rev counter typically over reads slightly so your 1100 on your dash will be closer to 1000. Still on the high side. It shouldn't stall now if that's your idle. __________________ 1991 90 quattro 20v sport 1991 90 quattro

04-09-21, 07:15 PM	#3
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Thanks for the advice, MikeS2 ... I'm a novice to the subject....

29-09-21, 03:06 PM	#4
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	My mechanic had a go at fettling the ISV with limited success. The engine now idles around 1000 rpm and hunts. At least it is not stalling. Maybe it is a cheap part after all. He is going to put my old ISV in his cleaning apparatus and see if that can be resurrected.

08-06-22, 06:58 PM	#5
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Having replaced the rubber bellows on my engine due to the vacuum leak it had, I thought I had cracked my problems. The engine was running much better but still a little rough. Then it happened again. The car just kept stalling. Swapped in my spare ISV and that seemed to do the trick, but I wasn't happy as I had been here before... The engine still ran a bit rough... The next time I used the car it stalled within 5 minutes of starting from cold. It re-started well and behaved for the rest of the day. This scenario continued day after day. I had no idea what to do. I thought I may as well change the dizzy cap and rotor arm while I had my head under the bonnet. The rotor arm turned out to be the wrong part so I just replaced the cap and fired her up. Stone me, everything seems to be working just fine now....

08-06-22, 07:13 PM	#6
Duffy3074 4 ring whore! Classic Audi Club Member Join Date: Aug 2015 Location: Dalgety Bay, Fife Posts: 2,078	Result!