TheLlamaGod

1.idle runs rich sometimes between 11-12
2.when i start the car and its already warm it sometimes idles at around 350rpm
3.in gear with out giving it gas the afr is jumping from 13-16. engine isnt decelerating as good when that happens and a lot of backfiring happens

vacuum lines were all replaced and venturi delete.

i even had a shop check out the car and they couldn't get any of the symptoms to show. they also said it was one of the more mechanically sound 944s that they've worked on.

vacuum lines were all replaced and venturi delete. new idle screw. adjusted properly

so i was wondering if anyone has any ideas as to what it could be. it really starting to bug me because it has been like this for a while now
TIA

CyCloNe!

Check FPR, TPS, ISV, AFM and maybe the injectors... Double Check to ensure your vac lines are correct, especially around your FPR and Damper on the rail. Hope this helps

Also check clarks-garage.com to do the test on those sensor's if you haven't already.

Darwantae951

MAF? MAP? AFM? What are some of the details of your set-up?

TheLlamaGod

the injectors where recently cleaned by witchhunter
everything is pretty much stock.
951max chips,LBE, 3.0 fpr

m73m95

Car runs normal everywhere except idle?

Coolant temp sensor..

Also, check the barn door isn't stuck in the AFM.

To rich is easy to diagnose. There are only a few things that can do it. Lean is the bitch to find.

TheLlamaGod

ill check the afm if i have time tomorrow.

car does run fine everywhere else.
where is the coolant temp sensor?

CyCloNe!

there are two, i think, check around where the intake manifold bolts to the engine. Should be one at the front of the engine straight across the firstspark plug wire. The second is around where the ISV is,under the intake manifold.

m73m95

Only one controls the DME. The other one is only for the gauge.

Its right in front of the engine, on the top above the BS roller (ish location lol).... Just look for the blue connector.

CyCloNe!

That's right, forgot that... that's for the reminder

TheLlamaGod

how would i know if its bad?
or are they cheap and just worth replacing for peace of mind?

m73m95

Yes, it is cheap, but Clarks garage has testing procedures as well.

Pull your air filter out, and stick a screw driver down the AFM, and see if the door is stuck open or moves freely without sticking anywhere.

I'd still bet on the coolant temp sensor, but checking the AFM is to easy to check to ignore it.

TheLlamaGod

is this the right sensor?

http://www.pelicanparts.com/cgi-bin/...89),%20Each%20

951Tom

This sounds like TPS or it's not adjusted properly for the idle switch. If I lift off the gas in gear, my a/f meter goes blank due to the decel fuel cut-out.

TheLlamaGod

it doesnt happen all the time. i thought it could be tps but i dont want to spend the money on a new one if its something more simple.

Tom M'Guinn

TPS is pretty darn simple to replace, at least compared to other things it could be. Having said that, no need to chase the problem with new parts. The TPS is easy to test with a multimeter -- go to clarks-garage.com and follow the test procedure he has. It will tell you if the TPS is good or not. If it only happens sometimes, that can sometimes be harder to find, but persistence in testing will ususally catch it. Also, the TPS might be adjusted poorly so that sometimes it closes the idle switch and sometimes doesn't, depending on how hot things are, etc. You might want to start by testing it and, if seemingly good, then adjusting it so that it clicks as late as possible -- i.e., so that the throttle plate can move as much as possible before the TPS clicks. That way, you have the best chance of always having the idle switch close when you let off the gas.