MAF PEGGED or NEED CUSTOM CHIP

[CONCRETEWARFARE]

Hi guys, I can not get my car to have really any power down low. I need to constantly run high fuel pressure, about 60psi vacuum on. If I try to set it to 39-41psi it either wont idle or will pop through the intake when I rev it. Once I start to get into the power band of the cam the car turns in to a rocket. Its just the low end torque is not there and there is always a miss down low. I was told by a shop that used to tune mustangs that I probably need a custom chip becasue the MAF is pegged. Do you guys agree? He says he can make the chip by me telling him everything done to the motor and program it from there. What other problem might cause this condition for the car?

 

[vristang]

Start by setting your fuel pressure with the vac disconnected, to 38-40psi.
The vac line needs to be off.

Let us know how that works, and we'll go from there...


jason

 

[CONCRETEWARFARE]

yea i tried that from the beginning. I finally got a hold of ed curtis and he said it sounds like it needs a chip and gave me a place to go.

 

[vristang]

Ed Curtis is from FTI, correct?


Did the problem start with the new motor?

What MAF are you using?
A pegged MAF will not cause idle/cruise issues.


Unless the FTI cam is just monsterous, I don't see you needing a tune that bad. Then again, all I know about your setup is what is in your sig...

I would hate to see you take the car to shop, pay for dyno time, and still have a crappy running car...

jason

 

[CONCRETEWARFARE]

Sorry my comp has been down for a few days. vristang then what do you think it could be? It has basically no bottom end and has a constant miss.

 

[vristang]

Timing and vac leaks seem common culprits.
Ignition timing can definately cause the issues you are describing.

There are others here who can help diagnose better than I can,
I just don't see anything in your combo that should REQUIRE a custom tune.


jason