Xfi 2.0 question on lt1

[L.Fite]

Got it...
Kinda what I suspected...
Is it tied physically to the throttle shaft or just lean/rich the mixture via controlled air leak?...

A friend resto-modded his street car with an LS-X and it hunts at idle...
Doesn't really seem to run like I would have expected a computer controlled car to run.
Seems rich all the time too...

Sorry for the questions but I really don't know anything about modern fuel injection.
Trying to learn.

If it ain't got pills or jets I'm lost!...

[Jeff Niceswanger]

Originally Posted by L.Fite

Got it...
Kinda what I suspected...
Is it tied physically to the throttle shaft or just lean/rich the mixture via controlled air leak?...

A friend resto-modded his street car with an LS-X and it hunts at idle...
Doesn't really seem to run like I would have expected a computer controlled car to run.
Seems rich all the time too...

Sorry for the questions but I really don't know anything about modern fuel injection.
Trying to learn.

If it ain't got pills or jets I'm lost!...

Its hunting because its not adjusted right, but big cammed cars and IAC are a challenge. The IAC has to be timed and adjusted to match up with the basic fuel map. The IAC is a little stepper moto or servo. It has a pindle, basically a big needle like in a needle and seat of a carb. It screws itself backward and forward seating, unseating, screwing just a little bit out, or a lot out. The farther it backs out, the more air it allows to "Go Around" the throttle body plates which in turn increases or decreases rpms. Thays about it, their isn't much to them

[L.Fite]

Originally Posted by Jeff Niceswanger

Its hunting because its not adjusted right, but big cammed cars and IAC are a challenge. The IAC has to be timed and adjusted to match up with the basic fuel map. The IAC is a little stepper moto or servo. It has a pindle, basically a big needle like in a needle and seat of a carb. It screws itself backward and forward seating, unseating, screwing just a little bit out, or a lot out. The farther it backs out, the more air it allows to "Go Around" the throttle body plates which in turn increases or decreases rpms. Thays about it, their isn't much to them

Thanks
Makes sense.

Can I PM you some day with more questions?
(rather than stepping on this thread)

[Jeff Niceswanger]

Originally Posted by L.Fite

Thanks
Makes sense.

Can I PM you some day with more questions?
(rather than stepping on this thread)

Sure, anytime

[Dave Gantz]

Originally Posted by L.Fite

Thanks
Makes sense.

Can I PM you some day with more questions?
(rather than stepping on this thread)

Start a new thread. I'm learning. I've had an 87 5.0 Mustang since new. I still know carbs better. lol

[john corcoran jr]

I've never been called the brightest bulb in the box so being a newbie to actually running a computer car, I took an EFI class. In the class we talked about the IAC. How many racers back in the day had controlled vacuum leaks on their cars in an effort to get more air into the motor? The IAC is a CONTROLLABLE vacuum leak and you can fuel around with it. Another thing I learned was do NOT unplug the IAC while the power is on. It will blow the circuit board in the computer and yes, Fast is aware of this glitch. I know, it happened to my motor while it was on the dyno and I wasn't anywhere near it. It is amazing what we can do with these computers compared to an OEM unit.