High idle problem?

[MIKESTANG_SVT]

This has been one hell of a day. After I get my shrader valve problem taken care of I run into something else. My idle is getting hung up around 1000-1200rpm's. After starting it up it sometimes it stays around 850-900, then if you hit the gas it goes up and then comes back down and stays at 1000-1200rpm's. I can get it to idle normal if I let the clutch out slowly while in 1st gear. It thens stays there till I hit the gas again. I recently had the car tuned and was told it was my iac, so I replaced it with no luck. I also checked for vac leaks and didn't find anything. I'm still using the stock tb/plenum with a stage 4 port and 2.76 upper. Other mods in sig. Anyone have any ideas?:shrug: My maf is in the fenderwell, I'm thinking about giving it a cleaning. Not sure if that will help?

 

[MIKESTANG_SVT]

ttt

 

[spincobra03]

check the tune, maybe the trims? Does it hesitate or surge at all during driving? Call your tuner would be my suggestion. GL

 

[MIKESTANG_SVT]

check the tune, maybe the trims? Does it hesitate or surge at all during driving? Call your tuner would be my suggestion. GL

No hesitation or surge while driving. Just has that annoying idle at 1000rpm when I come to a stop. The tuner told me they tried to fix it in the tune but they couldn't. My old iac did show some ware on the inside.

 

[FaYgOkRiS]

My cobra has always idled at 900 - 1000 rpms, never thought anything of it.

 

[MIKESTANG_SVT]

My cobra has always idled at 900 - 1000 rpms, never thought anything of it.

1000-1200 is were it gets hung up at. At normal idol,it is around 850-900 range. I've been using the search, but don't find any posts on the solution unless it involves an acufab tb or bad iac.

 

[MIKESTANG_SVT]

I disconnected the battery overnight and just gave it a try. It still gets hung up around 1000 but if i give it a little bit of gas, it idles nicely at 900rpm. It seems to be getting a little better. Maybe the computer has to relearn after disconnecting and changing the iac:shrug:

 

[Hockeyman48]

Check voltage on TPS

 

[MIKESTANG_SVT]

Check voltage on TPS

Thank you:beer: I'll start using the search button now. I'm going to need a new one of those next.

 

[xenodragon]

Whats the TPS

 

[MIKESTANG_SVT]

Ok. I checked the tps and it's at .98. I can't get the damn thing to move enough to get to .99. I'm not sure if the .01 is giving me the hanging idle or not? I'm thinking about taking the tps off and using a small file in the holes to give me a tad more movement to get to .99. Anyone feel free to chime in!

 

[MIKESTANG_SVT]

Whats the TPS

I think it's throttle position sensor but I'm not positive:shrug: I just found out about it yesterday

 

[jm@ReischePerf]

Even 900 is a bit high for a warmed-up idle, do you know what your idle target speed is set at in the tune?

 

[MIKESTANG_SVT]

Even 900 is a bit high for a warmed-up idle, do you know what your idle target speed is set at in the tune?

I think somewhere around 800. I just set the tps to .99 and it runs way worse than when it was at .98. Now it bounces from 250 to 750 then stalls out. I'm ready to give up and trade the pos in:fm:

 

[Juruense]

Clean MAF, reset PCM

 

[MIKESTANG_SVT]

Clean MAF, reset PCM

I have cleaned the maf, but I did notice something. I just disconnected the battery for 20 mins. then re connected and started it up. The damn thing idled perfect and drove perfect for 15 minutes. Then the pos went back to getting hung up at 1000rpm's.:shrug: I have the battery disconnected again.
Could the MAf be bad?

 

[Juruense]

Hmmm, try doing the below in the exact order:

-clean MAF
-reset PCM
-use procedure in owner's manual to relearn fuel trims

Also there is some weird multi-step procedure for learning fuel trims with Accufabs with idle issues. Maybe a search would find it I know people have posted it several times... You have an Accufab right?

 

[xenodragon]

Mike you have like the exact same setup as me, and the same issues as me....ever since i got the port and the tune my idle is a little higher than normal...like 1000-1200, eventually it drops back down to 900. But on a cold start up after it has sit over night for instance, the rpms will shoot up way high then drop allll the way down to like 500 and stall out.

I am pretty damn sure its a fuel issue (obviously and if my tuner would call me back I could possible figure it out)

Please let me know if you figure out the problem because we might have the same problem.

Have you checked your FRPS? Does it smell like gas when you start the car up? Right now thats what i am thinking is my problem but no one is calling me back to help me so I am lost.

 

[MIKESTANG_SVT]

Hmmm, try doing the below in the exact order:

-clean MAF
-reset PCM
-use procedure in owner's manual to relearn fuel trims

Also there is some weird multi-step procedure for learning fuel trims with Accufabs with idle issues. Maybe a search would find it I know people have posted it several times... You have an Accufab right?

No acufab here. It's kind of ironic now. I didn't upgrade to one after reading all the problems people had with adjusting there idle. I had know idea I would have an idle issue anyway-lol. I don't have a manual to relearrn the fuel trims. What exactly is the fuel trims? By resetting the PCM, is that just disconnecting the battery for 15 mins?

 

[MIKESTANG_SVT]

Mike you have like the exact same setup as me, and the same issues as me....ever since i got the port and the tune my idle is a little higher than normal...like 1000-1200, eventually it drops back down to 900. But on a cold start up after it has sit over night for instance, the rpms will shoot up way high then drop allll the way down to like 500 and stall out.

I am pretty damn sure its a fuel issue (obviously and if my tuner would call me back I could possible figure it out)

Please let me know if you figure out the problem because we might have the same problem.

Have you checked your FRPS? Does it smell like gas when you start the car up? Right now thats what i am thinking is my problem but no one is calling me back to help me so I am lost.

A couple guys at work think I have a fuel issue also. I did upgrade to 60lb inject. but kept the stock fuel pump. I tried checking my FRPS, but I don't know if I did it right? I just unplugged it while the car was running and idling at 1000. It never changed the idle at all. At this point, I'm ready to just replace any little thing I can to narrow it down. I've had the battery disconnected since last night. I'm going to clean the MAF one more time and pray it just goes away. I will def. keep you informed on what is going on. I have contacted my tuner as well. They have been helping me a lot. They are 2 hours away so I'm trying my hardest to fix it myself.