P1SC Idle Problem

[D1_PROCHARGED]

I've installed a P1SC with the 3 core intercooler on my friends' car and I'm having some problems with the idle and half throttle.

The car is a 1999 Mustang GT and has:

P1SC with the 3 core intercooler 10 PSI
2003 Cobra Fuel Pump/Tank
FMS 42# injectors
01 90mm Lightning mass air meter
AWSF 22C Spark Plugs gapped at .35
JMS Chip

I can't get the idle to be stable even after rotating the MAF 360 degrees, it flactuates between 850 rpm and 1000 rpm!!!
Also, it will hesitate with the part throttle. Under WOT condition it shows full boost and a steady fuel pressure of 45-50 PSI and pulls hard. Sometimes it will buck while decelerating.

What do you think the problem is? Is it the MAF? Go for a universal, if so well I need a reburn for the chip? Or is it the burn of the chip in the first place?

Your help is appreciated and thanks in advance.

[WA2FAST]

It's really hard to say. It sounds like either a meter or tuning (chip) issue to me. Have you tried running the car with out the chip in just to see what happens? I wouldn't suggest taking the car into boost, but I would be curious as to what happens at idle and also at part throttle. Also, have you tried a different meter? Same thing... if you can, I would give a different meter a shot... but I would first try with out that chip, it seems more and more often, people are having problems with 'over the counter' chips... one reason no matter what any kit comes with, custom dyno tuning is more valuable than anything... a VERY important piece of the puzzle.

[RACINJASON]

IF YOU RUN THE CAR WOTH OUT THE CHIP DON"T GO INTO THE BOOST I JUIST BLUE MINE O2 UP BY NOT USEING a chip.

[D1_PROCHARGED]

Thanks every one for replying. I was out of town for a while. I contacted the person whom I got the chip from and he will talk to JMS. Hopefully they can make something. I will keep you updated.

[D1_PROCHARGED]

Hey again!

I got the reburn from JMS. He leaned it out a little from idel to 3000 RPM, the car drives a little better but still idles kind of funny.

Overall, there are improvements in the drivebelity and the idle.

Here is the quistion, they recomended reading the MAF voltage, how can I do that? Is there a specifec device to do it?

Thanks in advance.

[WA2FAST]

Tap into wires C&D on the harness that go to the meter... I beleive if you are looking at the meter, right side up with the plug facing you, it's the left two pins. Tap those wires and that will give you the refrence voltage that the computer is seeing. You can get the wire color and tap it inside of the car at the computer if you would like to see what it does as you drive. I'm sure they just want what it is doing at idle though.

[D1_PROCHARGED]

Thanks for replying WA2FAST.

Do you have an idea what range of voltage I should be in? i.e. at idle, full throttle, max voltage.

I'm just trying to get away with this maf, otherwise I have to get the Pro M Univerasal maf.

Thanks

[WA2FAST]

Well, if you are following my other post... the Pro-M Univer is a great concept, but is strictly a tuning piece... it is not a true bolt on, your car will run out of the box better with your meter probibly than the Univer. My Univer is completely out of range, as most of them are (mine is quite a bit worse than others, completely un-acceptable to be honest with you). Anyway, I am not sure if all meters are supposed to be the same or not, but I know for a fact that my acceptable voltage range (#42 Blow Through callibration 3.5" Univer) is between .600 and .900 volts at idle with .700 to .800 being optimal. Again, I am not sure what the voltage should be for your meter weather it would be the same or not, but maybe someone on here will know better. If not, you can call up Pro-M and ask them.