hey guys...i was wondering if there is a idol adjust screw on the throttle body? i have an 04 ranger with the 4.0 4x4.......dudes at the dealership told me its all computer controlled, is this true? my truck idols at 600 they said its a normal idol for the rangers...i'd like to get mine up at around 800-850 range....what ya guys think?

 

should be one, idk tho, take off the little 4.0 cover and look.

 

There is no idle screw, it is all controlled by the computer.

 

Your computer is "commanding" a idle speed. Stock on your truck should be 704rpms for both free idle and when in drive. It could be 650 or maybe 750.. I don't know for sure. (My 2006 is 704rpms)

The computer does this several ways. It's adjusting the timing first and foremost for the finite adjustments. Then it's operating the IAC & fuel injection pulses to balance the a/f.

If your idle is smooth but just low.. I'd think the computer is getting some wrong signals.

I'd start off by checking for vacuum leaks. Then clean the MAF wire. Then clean the IAC. A MAP sensor could cause this too.. but I don't know how to check one other than to look at it's readings with a scanner.

*IF* you could adjust the throttle with a screw the computer will be trying to adjust it back to what it thinks is 704rpms. So it'll most likely reduce timing, close the IAC somewhat, and start adding fuel. I would'nt be supprised at all if the idle got worse if you could do that.

Rich

 

on any fuel injected motor nomatter what it is you should never mess with the idle set screw. even tho some models come with it they arent sopose to b messed with unfortuniatly

 

^^there is NO idle screw on the Rangers nor any other computer controlled fuel injection vehicle.....idle screws are on carb'd engines....

the Rangers idle is set in the computer.....the ONLY way to change that is to reprogram the computer......and you can change the idle via programing by using a XCalibrator 2......i have my idle bumped up to 1048 RPM's....

 

My 02 has a screw that looks like an idle adjustment screw. I don't know if all fuel injected Rangers have them but it is used to adjust the throttle plate at idle. If the throttle plate closes to far at idle , it can hang up on the throttle body and cause sticking.

This screw should not be used to try to control idle and will not unless you adjust it too far open.

 

That screw should ONLY be used for setting the TPS voltage, NOT the idle speed!!!

 

Not true. Not only is it not true.. but sometimes it is actually there to adjust the amount of air entering at idle. It also keeps the blades from touching the body. That does two things. The computer adjusts for this and trys to get the idle back to the commanded rpm. And it prevents debris buildup where a ridge might form from the two touching.

If you want proof.. I can post a pic of my stock Lightning TB.

Rich

 

did not realize that.....i always thought that the screw on the TB was the flapper thingy adjustment.......which shouldn't be used for idle control...

 

Where did I say it should be used to adjust the idle speed?

 

You didn't, I'm sorry! I should not have quoted you!!

 

i've done it before on fuely motors..thats why i asked...i think wydopnthrtl
is right..it controls the butterfly and the TPS will refig itsself...IMO if ya reprog any computer on a vehicle it will work its bugs out.(figure its own system back out) im not talking MAJOR differences...cuz it wont refig itself on huge changes. im going to check mine out and see