Operator

well, here we go again. My problem is an idle stumble + cutout.
when coming to a stop and pushing in the clutch sometimes my idle will drop to 0. the funny thing is, it wont just drop from wherever to 0, it will come down to proper idle level (~900) and then after 5-10 seconds it might cutout. sometimes it will recover. sometimes it wont.

so in chasing down the problem I finally cracked open my AFM yesterday and moved the wiper arm up to a fresh new spot on the ceramic strip, sealed it up, installed it, went for a drive today, and it still stumbles sometimes.

does anyone have any clever ideas? this is driving me mad. and it appears to be getting worse... half a year ago it was only ocassionally bad.. now it happens more often. help thanks.

Bri Bro

Spray some WD40 into the idle stabilizer. If that doesn't help, pull the intake and inspect/replace all the vacuum line.

Chris_924s

Simon, I agree. Rule out the vacuum lines first. THEN consider replacing the FPR. (A GUESS)

Pulling the intake is a hassle, but rule it out. if air is getting into the intake beyond the gasket some shadetree diagnostics will prove it. Try some carb cleaner at the intake and if it gets sucked in the idle willl rise....

Best of luck- Chris.

Operator

thanks guys. I see in older threads that the ISV is mentioned as well.
where is it?
any by "intake" you dont mean the tube going from the AFM to the engine?
The obvious stuff isn't so obvious to me

triscadek

The intake is bolted to the drivers side of the head, has the 4 tubes going into it. The ISV is under the intake manifold with some vac. lines running to it.

austin944

I had a similar problem where the car would sometimes idle low, and stall when pushing
in the clutch when slowing to a stop. I fiddled around with the vacuum hoses, and wiggled
the little round rubber piece on top of the throttle body, and the problem went away. Don't
know what I did, but I'm glad the problem's gone!

hosrom_951

First of all, does it stumble when cold or warm (that would rule out the ISV)

It could also be vacuum related.

Operator

it stumbles when cold and when warm. i know this for a fact, because i can get it to stumble right when i drive down the road to the first stop sign and i can almost always expect a stall after coasting off an exit ramp after a long highway drive.

i replaced my o2 sensor last year to remedy this problem because it was only happening in colder weather. but the problem came back.

austin944 can you show me a picture of this rubber piece you messed around with?

pete944

I had the same stumble and a new DME chip cured it completely. The good news is that the chip only cost me $25.

Here's the thread:
https://rennlist.com/forums/924-931-944-951-968-forum/168723-installed-new-chip-today.html

Operator

yea that would be amazing if it were the DME but I've tried swapping it. guess ill try swapping it again but I seriously dont think its the DME, because now its a little weirder.. after theAFM refurbish.. the way it dies.. I might have to crack that puppy open again and move the arm down instead of up this time.

austin944

Operator,
The small bolt in the middle in the pic is the thing that I wiggled.

triscadek

I moved the arm on my AFM, but apparently the bad spot was too big and either way doesn't help.