Are there any tell tale signs that the ISV has gone bad? I've been dealing with check engine lights and slight hesitation during take-off lately and it always goes away with an ISV cleaning. However, lately the check engine light has been coming on more often along with the hesitation and it's driving me nuts. I take the ISV out and clean it, and the car runs great again and the check engine light clears itself after driving around a bit. Couple hundred miles later, check engine light again along with some hesitation. Clean, and repeat. Going nuts.

I just cleaned the MAF as well and I don't suspect the MAF to be an issue. I can't seem to get my ISV 100% clean though...and I notice it's valve movement is kinda noisy when I'm cleaning it.

Do I need a new one?

By the way the check engine code is 1129 (if i remember correctly) - the one for the 02 sensors (which where already changed 30k miles ago).

 

When I was buying all of the "while you're in there" bits and pieces for my top end rebuild, Steve Weiner suggested that I think about replacing the ISV (especially since I was going with a lightweight flywheel for my '95). Although keeping it clean is important, he told me that it will eventually fail. I decided to hold off on replacing it until now since I was experiencing symptoms of a clogged ISV more frequently.

The new ISV arrived from Sunset Porsche yesterday and I'll put it in this weekend. According to Jeff at Sunset, the remaining ISV's for sale are warehoused in Germany so it may take a while to come in. Cost for a replacement is now around $330.

 

Connect the ISV to a 9V battery and check if it works.

 

Good info, thanks! Please do let me know how the new one works for you! How many miles do you have?

Should I be able to observe the valve turning?

 

104,000 miles

 

If you do need to purchase one, the best price (for now! stay tuned ) will be here:
http://www.autohausaz.com/search/pro...ontrol%20Valve

Still $281... but same Bosch part Porsche sells, just not sourced through Porsche for $330

Sorry Jason...

 

Awesome...but the "stay tuned" bit, don't leave me hanging! Would it be in my best interest to postpone my purchase of a new ISV?

 

hmm... sorry, maybe I shouldn't have said that. Could be weeks.

 

Yes, the valve will move.

 

just cleaned my ISV.when i took it out it was black inside and the valve didnt move.after spraying it with carb cleaner...i twist turn the valve and it moves...u will hear a clack clack clack sound.

 

whne I turn mine it makes more of a clatcheak-ukitakaught-ehkita sound when clean

 

The ISV failed on my car. It is a wear item.

GL

 

Cool thanks.

Yes, I've clean mine a few times, the problem now is I have to clean more often and I suspect the ISV has gone bad.

lol

Thanks, I'm pretty sure mine is failing as well. Did you get any check engine lights and if yes, do you remember the codes? Thanks.

 

No CEL because the RS had OBDI only. Was quite good really!

 

Oh, right! Duh!