Hi guys, my 96, 4.0 auto HO, sport, limited (man...what a mouthful)
has just started something new. When she starts she climbs on revs, almost like you put yr foot on the gas, and then she settles down to about 1000/1100 rpm. I have noticed that as she warms up, she settles at 900-1000rpm. This seems a tad high still? Ive checked vacuum lines and I cant find anything obvious, I replaced the line to my MAP sensor (just in case) and that didnt change anything. Ive checked the accelerator cable, cant seem to find anything sticking there. I have no O2 sensors, and no CAT so ive been told this thing runs in open loop mode? what else could be doing this, and how do I get my revs to drop to 800-850 ? Oh, it is winter here in South AFrica, and she does sleep outside, and it has become quite cold...........

 

iac or the tps is probably your culpret try tamking them offand cleaning them just use some carb cleaner or something similar there are a few writeups on how to do this just search here or google you should be ok

 

Ok Cool....umm.....what is a iac or tps...?

 

not 100% bout the HOs but they are sensors on the throttle body

TPS-throttle position sensor
IAC-idle air control valve(or in the picture he has it labled AIC)

 

yes they are both located on the throttle body they are held on buy 2 screws each on the iac make sure to save the gasket or get a new one