I have an 86 S4 NA. When the engine is cold it runs really good. But after a couple of minutes I can't keep the rpms at a constant speed between 1200 and 3000 rpms. Between 1200 and 3000 the motor gains a couple of hundred rpms and them loses them. Over and over. Above 3000 rpms it runs fine. Below 1200 it idles great.
I checked the TPS and I checked for vacuum leaks. The timing is OK. I've searched and searched. Has anybody ever had this happed?

 

Well, from my understanding, there's no real way to adjust the TPS on the S4's, so it may just need replaced.... but, I don't remember....

 

Yes, you CAN adjust the TPS on a s4.

Vac leak or faulty TPS, or a number of other things. Read teh FAQ!

 

and this is why I drive an FD

 

You're a little lost in the FC section then!

 

way wrong,

You should refrain from answering /posting if you don't know

 

yep... I agree...

TPS or vac leak.

Check the TPS at the ECU or at the diagnostic plug, rather than at the plug for the TPS.

 

Yeah, that's good advice checking it at the ECU, I've noticed a lot of people who check the TPS itself and it's perfect, yet nothing ever works, then finally they check the ECU and find their wiring is so bad it has resistance of it's own, or simply doesn't show up!

 

Checking it at the ECU solved it on the last one I fixed that on.

yet the wiring was flawless, less than .002 resistance between the two ends.

 

Thanks guys, I'll check the TPS at the ECU.

 

Thanks for the advice but the FAQ doesn't cover this.

 

:wall: I was an FC owner, just trying to be nice

 

lol, FD more reliable..lol

 

 

The FAQ has the FSM, and the FSM covers this!

 

If that's you in the avatar, I'd be glad to come down and adjust it for you, I live pretty close

 

 

Yep, thats me. Not a very good pic though.

 

A chick that digs trying to figure out what's wrong with her own vehicle and looks like that? I'll hump her leg if she lets me

 

Gdhsf....

 

^ agreed, i hate when people do this. someone wants some help and this crap just drives them away, i personally appologize for that!

 

Try adjusting the BAC valve. Thats what did it on my rx. First, try turning it clockwise.

 

Dude, it was a joke.. lighten up... besides, the answers were already posted at the beginning of the thread...

****, you talk about driving people away, It's a suprise that there are as many members in the 2nd Gen community as there are. Considering how rough they get treated when they post a simple question that's answered with SEARCH and all this other ****.

I've just recently started to get a little more involved and feeling more comfortable posting around here. Thus, I was goofing off a little bit. The only people driving others away are those of you jumpin other people over stupid ****. Get a grip. Would you have rather I attacked SonicRat for posting a dog humping a person's leg or just gone with it?

 

GO WITH IT, wow, calm down man. i to hate it when i get slammed for asking questions already answered. for the longest time i wouldnt post anything and just either pm someone or READ.the way i see it, its gonna happen no matter what so*shrug*