1989 audi coupe q 5cyl 7a engine...

ok... not long ago I cleaned the ISV, all the little pipes, everything (ISV is pretty new too).. and I just put a new oxy sensor in it a few days ago. Tonight the idle seems to be sticking in EVERY gear, and even in neutral.. i mean it goes up REALLY high. When we were at a stop light, it was in neutral, my wife pushed the clutch pedal all the way down, as if she was going to put it into first, and the idle started to rev up from around 900-1000 rpm to a little over 3000 rpm, without her touching the gas. It has never done this before. Then when switching gears, it would stick at a high RPM for awhile and finally go down to where it was supposed to be. Sometimes when stopped after the car revs up really high, it goes back down to around 900 rpm or a bit lower, and the car seems to almost be stalling out. What is going on here?? I wanna get that fixed since i was hoping to get better gas milage with the new oxy sensor, but all this reving is not helping Any help would be great!!!

 

http://images.google.co.uk/imgres?im...l%3Den%26lr%3D

check the pipes going to it they get clogged up with carbon

[IMG]local://upfiles/12092/2BD3F325084249ED874115BC5B723116.gif[/IMG]

 

Check you throttle linkage to make sure that it is not sticking, Also check the dashpot, most CIS equipped cars have one.

[IMG]local://upfiles/1095/5D4EEC1706CF4EF5ACE97FF93784E0C3.jpg[/IMG]

 

Thanks for the info.. the aux air valve is the ISV then right? I can take it out again.. i HOPE thats what it is.. but i took it out about a month or 2 ago and it was clean clean.. i guess it wouldnt hurt to check it out. thanks

could it be anything else?

 

item H

[IMG]local://upfiles/12092/5AD5A366F9A244C18868AB92B5DD7BA5.jpg[/IMG]

 

OK i will check that out. The item H aux air valve is like my ISV. I have seen another 5 cyl version with that same thing. I will also check out the linkage.. would i lube the cable up with some kind of grease? (pet jelly or something like that).

Could low tranny oil cause it too?? (i have to get a side seal replaced bec its been dripping lately)

 

I use WD40 for lubing grease tends to go hard with the heat

 

Low trany oil in manual gearbox, no?

You either have an ISV or Auxiliary Air Valve, not both.

It can also be a vacuum leak.

I wouldn't use WD40, I found out the hard way that once it evaporates it leaves a sticky and gummy residue. Grease would be my choice.

 

I ment gear oil when i said tranny oil (sorry hehe). Yeah I suspected a vac leak for sometime.. but i didn't find any holes or anything in any tubes that go to the ISV(yeah i definately have an isv). The only tube i suspect is the BIG one that goes from the TB to the air mass meter. Where the crankcase vent tube goes into it from the underside, the hole is more oval now, and i think maybe some air is gettin in there. I dunno where else there is a vac leak. This is the worst the idle has EVER been.. so I dunno.. thanks for the help. I will do some inspecting tomorrow morning.

 

just one point the ISV is called the IAC (idle air control valve) there are two types a rotary or solenoid type