Little bit of trouble [Archive] - Audi Forums

: Little bit of trouble

04-25-2011, 07:55 PM
Hello fellas I just bought a 1990 Audi Coupe Quattro and I am having a couple diff issues that I would like to figure out. So if u guys could possibly point me in the right direction. Ok so the car starts and runs fine down the road but as soon as u put the clutch in it searches for idle or dies is the first issue, and the next one is both window regulators are shot. Was wondering where could possibly locate. Thanks in advance,


05-20-2011, 11:34 AM
Hey Jason...Greg here. First off welcome to the forums....glad to have you aboard. Well these cars are very common to carboning up. If it's wandering for idle, you need to remove the ISV(idle stabalizer valve) located on or near the MAF which both are on the intake boot. Take the ISV off and clean the ever lovin' @%#$ out of it with throttlebody cleaner...again and again and agin until there is nothing but clean liquid coming out. Then....clean it again and again. After your ready to throw it against a wall...(lol) shoot alot of WD-40 in it to lube the actual valve in side then re-attach. It wouldn't hurt to remove the intake boot and fire a @%$#load of throttle body cleaner into the intake itself while the car is running. Good luck and let me know how you make out. Cheers!

Oh and for the window regs...ya you'll have to search for people parting these cars out to find those as they are NLA.

weekend in whistler
05-28-2011, 06:38 AM

BG Company (

I'm not a big believer in the "mechanic in a can" but check out these products. If you click the home screen you can punch in your postal code and find a BG shop close to you. if you have a rough idle or your Audi is close to stalling out or is stalling but the no codes are present then I would take your car to one of the garages close you that carries these products.

Ask for the decarbonization/fuel system treatment. It should be around $150 (that's what we charge for it) and then a can of BG compression restore (part #109) then an oil change.

the service needs to be done outside because these are very strong chemicals but man does it ever clean out the intake system and valves and the compression restore cleans the carbon deposits off the piston rings. Make sure you have your oil changed right after as chunks of carbon will drain out. Most of it will burn off out the tailpipe though.

these products cannot be purchased at any parts stores (as far as I know) because they are so strong but they really work.

Have you ever heard of "sea foam"? Napa carries this product. This treatment is like that times 5...

weekend in whistler
05-28-2011, 06:40 AM
As far as the window regulars I know where there is an 88 quattro that I have been picking parts from that I could greyhound you...

05-30-2011, 12:27 AM
Ummm ok...I've owned 4 coupe quattro's a 90 quattro 20v and 2 coupe gt's and yes the products you speak of can be bought at selected parts stores but those products don't ever come near the ISV valve or MAF on these 20v 7a engines. Trust me Jason 9 times out of 10 the wandering idle issue on these 20v 7a engines has to do with gunk build up in the ISV valve causing the valve to stick. Yes you can put these high concentrated high cleaning agents into the intake but I don't recommend it at all. But it's your car and your call. I'll never put anything other then throttle body cleaner or WD-40 into idle valve which also have many sensors actached. And no;s not a mechanic in a bottle.


weekend in whistler
06-01-2011, 09:00 PM
jason / greg,

greg is right for cleaning the sensors and ISV. I misread what he had written. what i was talking about was for cleaning the carbon build up that can build up on the butterfly valve and intake / exhaust valves.

Greg - all i meant by the "mechanic in a bottle" comment was all the products out there that say their stuff will make the engine run like it was new again... Very few actually solve the issue and I've been quite impressed with the BG line of products. We carry their full line at the shop along with the tools and have been quite surprised to see them actually work.

Anyways greg, just wanted to let you know I had misread what you wrote and thought you were talking about the intake/exhaust valves.


06-07-2011, 05:57 AM
Cheers Jon...No harm no foul!!