exploder idle issues

[AgPete139]

Hm.

• You could get a volmeter and make sure your TPS is at ~.90 - .99? (What you do is get 2 small pins, stick them in the TPS wires, and measure them with your multimeter device. Idle should be around .90 - .99 volts while WOT is going to be well over 4.00 volts.)

Also...

• Did you pull the automotive trouble codes yet?

So, I just thought about these:

• Could it even be oxygen sensors?
• Is it getting really cold where you are, and the motor is compensating?
• If you are absolutely sure there are no gasket leaks, and your vacuum lines are all hooked up, have you considered fuel?

We'll try and get you straightened out.



Pete

 

[85ranger302]

i replaced the tps, i pulled codes and all i got was dtc412 which is cannot control engine rpm during koer high rpm test, at one point i got 411 which is cannot control engine rpm during koer low rpm test, and 538 which is three codes in one, insufficient rpm change during koer dynamic response test, unvalid cylinder balance test due to throttle movement during test, and invalid cylinder balance test due to cid circuit failure. and i replaced the o2 sensor when i swapped out the transmission. i also know that the fuel pump sender needs to be replaced though cause my gas gauge is even more untrustworthy than they usually are. and i did the upper and lower intake gaskets about two months or so ago. and this is confusing the hell outta me

 

[85ranger302]

ok so now that it is getting colder my motor is pulling itself up to like 3000 rpm in park sometimes, but not till it reaches operating temp, and its really confusing me now

 

[84bluebronco2]

I wish i could tell you something but my 4.0 just seems to stall immediately after starting rather infrequently. Good luck and hope you get it sorted very soon!

 

[85ranger302]

yeah me too, its really confusing the hell outta me

 

[Nathan123]

Well my 2.9 bronco ii was having most of these syptoms. I had a 1/4" thick aluminum adjuster plate between the IAC and intake. I took that out, put a new IAC on. Still didn't work right. So I cleaned the TB and found that someone messed with the idle speed set screw. It was backed so far off that it wasn't touching the lever on the cable. So i played with it till I got a reliable return to idle of around 850 (like the sticker says) when idling in park (when warm), and even just when coming to a stop. Not sure if the 4.0 has that screw set up though. It seems to me like the truck was compensating for running all gummed up and now that it's new again, it doesnt know what to do.

 

[dorramide7]

pull the codes and see it the tps is the problem or something else, I cleaned my MAF with vinegar and what a difference it made, no more hesitation.

Louis

This happened to me once. I dunno that it's your problem, but my issue was that my TB had been so gunked up for so long that the computer had learned to deal with it by opening the IAC further. I went and removed the gunk and the computer didn't adjust very well. I had to go and manually reset my idle speed.

 

[85ranger302]

is there any way the transmission or torque converter could affect the engine idle? cause i think my converter is clunking whenever i shut the motor off

 

[Nathan123]

You can always check the kickdown linkage to make sure its in adjustment.
http://www.therangerstation.com/forums/showthread.php?t=92780

WTF posted how the kickdown is adjusted.

 

[85ranger302]

ok so i swapped out the tps last month and i think its bad, cause i keep getting the "throtte position sensor below minimum voltage" code, so im gonna put a motorcraft tps back on it.

 

[AgPete139]

Gluck.