Warm Idling issues? Need opinions.

[pslinux]

So I finally got my fuel pump in and everything back together.

Test Drive time. I let it idle in the driveway maybe ten minutes before I left and everything was fine. Drove in about 5miles to the gas station, drove great. Parked in front of the gas pump and it was still idling fine.

Turned it off, filled her up, started just fine but as soon as it gets to idle rpm it falls flat and dies. I can keep it running with the gas pedal and it still drives fine but no idle what so ever.

Drove it home like that, only one stop light so it only cut off once on the way home and still pulled nicely. Got home, parked in the driveway and then it was magicaly idling fine.

Now the car does have a procharger and hasn't been tuned. Just the chip that came from procharger with the kit. I'm leaning towards it being a tune issue. I checked for vaccum leaks and it was steady at -20psi or whatever the unit.

Anyone have any ideas?

 

[9Terminator6]

Def. A tune issue!

 

[STAMPEDE3]

Could just as easily be the IAC sticking.

 

[mwolson]

The IACV is easy to test. Just put 12V across it and see if it clicks. It is either open or closed, and the PCM modulates the air flow with Pulse Width Modulation (PWM).

 

[pslinux]

I thought it was the IAC as well but I put a new one on it. Didn't change anything, although I could have gotten a bad one.

 

[Bright Blue Cob]

Cleaned the MAF?Tried taking off the belt for the supercharger?

 

[pslinux]

Cleaned the MAF?Tried taking off the belt for the supercharger?

Negative. I will try that.

The car seems to act overheated when I try to start it right after getting to my destination. As soon as I get driving into clean air it will idle fine again at the next stop. Temp gauge (stock) reads fine though. I'm going to datalog with my buddy's tuner when it starts acting up. What should I look for? Also seems to do better now that I'm driving it around.

 

[pslinux]

So I went to try and datalog during the issue and had problems connecting through the laptop. But could log on the hand held itself.

Anyway, I tried looking up my STFT and it just showed Invalid. I don't know if my procharger piggy back chip could interfere with this though. Also when trying to connect with the laptop, the parameters came up in livelink as if it were a diesel truck. Wierd.

 

[mwolson]

Yes, a chip will interfere with datalogging.

You need to get an OBD2 "blocker cable" to be able to datalog a PCM with a chip. SCT used to sell them, but I haven't seen them on their web site recently. You should search their web site and/or call them to see if they still sell the blocker cable.

 

[pslinux]

Well...

I'm kind of in the middle of piecing together a way to get rid of the chip and the FMU. So far i'm working on either 39 or 42 lb injectors and maybe a new MAF and then ditch the chip and FMU. Then start a remote dyno tune with someone that knows what they're doing. Or get the car running well enough to drive to a shop. There aren't any I know of close to by.

 

[mwolson]

Well...

I'm kind of in the middle of piecing together a way to get rid of the chip and the FMU. So far i'm working on either 39 or 42 lb injectors and maybe a new MAF and then ditch the chip and FMU. Then start a remote dyno tune with someone that knows what they're doing. Or get the car running well enough to drive to a shop. There aren't any I know of close to by.

Making those kinds of changes will require a complete new tune. Since you will be starting from scratch, you might as well not worry too much about trying to fix things.

You could test the IAC like I recommended above, and it wouldn't hurt to clean the MAF. You don't need a new MAF unless you peg the old one. You could check for metered air and vacuum leaks using a cigar. There's a video on Youtube that shows you how.

After you have the ability to datalog, it will get easier to diagnose issues.