Fox idle issue...

[V8tt]

When the car is at a stop the rpms will flux between 900 and 750. It will idle to 900 for about 3-5 seconds and then drop to 750 for about the same amount of time and then go back up. If I turn the ac on it will go to 1000 and stay there. Is this something I should be concerned about? I just picked the car up as it sits a couple of weeks ago. Below are the specifics that will help you gurus:

BBK headers
Flow Master muffler
polished Paxton Novi 1000
polished Cobra intake
polised intake tube
cobra heads
lunati cam (dont have the cam card so I don't know exactly the duration and separation)
msd wires and cap and rotor
electric cooling fan(flex alite)

Thanks guys. When I get past being a complete retard and figure out how to post pics I will get some up.

[jnobles06]

i wouldn't worry about it too much since it's a 5.0, that is cammed, and blown. if your are really worried though i would check for vacuum leaks, check the tps voltage, and check the IAC valve.

[V8tt]

i wouldn't worry about it too much since it's a 5.0, that is cammed, and blown. if your are really worried though i would check for vacuum leaks, check the tps voltage, and check the IAC valve.

Cool..will do. Thanks for the info.

[TEAMJACOB]

When the car is at a stop the rpms will flux between 900 and 750. It will idle to 900 for about 3-5 seconds and then drop to 750 for about the same amount of time and then go back up. If I turn the ac on it will go to 1000 and stay there. Is this something I should be concerned about? I just picked the car up as it sits a couple of weeks ago. Below are the specifics that will help you gurus:

BBK headers
Flow Master muffler
polished Paxton Novi 1000
polished Cobra intake
polised intake tube
cobra heads
lunati cam (dont have the cam card so I don't know exactly the duration and separation)
msd wires and cap and rotor
electric cooling fan(flex alite)

Thanks guys. When I get past being a complete retard and figure out how to post pics I will get some up.

I don't think anyone could begin to diagnose the problem without knowing what all was polished

[TENGRAM]

stock (manual trans) tune calls for an idle of 670rpm. Disco the IAC valve and set your throttle stop screw so that the idle is below that. Reconnect the IAC, shut the engine off and restart it, and then give the ECM time to learn.

[jnobles06]

stock (manual trans) tune calls for an idle of 670rpm. Disco the IAC valve and set your throttle stop screw so that the idle is below that. Reconnect the IAC, shut the engine off and restart it, and then give the ECM time to learn.

i was going to suggest to reset base idle, but i figured it was pointless with cam and blower; especially with a big cam.

[jnobles06]

I don't think anyone could begin to diagnose the problem without knowing what all was polished

i noticed that too. lol. to each his own.

[Dacotua]

On my old h/c/i forced induction fox, I did the following.

Disconnect the iab. Get a buddy to start the car. Adjust the throttlebody blade stop until the car runs about 800 rpms.

Turn off car, unplug battery, reconnect iab, reconnect battery.

Never had a issue after i did that