Just did the swap Monday. Upon startup when cold it rpms at 2100 then drops down after a minute
Will this hurt the engine? It's supposed to be 5 when I leave tonight
We re used the iac and Tps from the 2.5
Ground the tab on the 4.0 tb off
New gasket for the tb
Anyone have this experience? I've driven about 20 miles since the swap
More power but the high rpms bother me
Also it seems my temp is running hotter now
I'm concerned that it will hurt the engine upon start up
I had the exact same issue several years ago, if I recall I cleaned things up really well, and I used the same parts as you did to remedy the problem. Make sure everything is sealed nicely and that everything is clean and working proper.
I just cleaned them really good, and I reset the computer as well just in case, mine would not idle down for the longest time. In fact when I first swapped it all over the idle ran straight up to redline. Clean everything up, while doing so disconnect the battery to let the computer reset. It was when mine jumped to redline that I realized I had to swap some of the 2.5 parts back over.
I put the 4.0 on mine for awhile and did exactly everything you did. Same thing happened. Idled high for awhile when first starting it after it was warmed up and then it would go back down. That drove me bat$hit crazy cuz I could never figure it out. Threw the 2.5 body back on and it works fine. Wonder if it has something to do with the diameter of the intake not matching the throttle body. I'm assuming you didn't mill the intake for for the larger throttle body right? That was the only thing I could think of that might have an effect on the idle?!?!
Crazy, Cuz that is exactly what my 2.5 needs. Right now I have to keep the throttle on in the mornings to keep it running, then, once it warms up I can let off the throttle and it will ease on down to about 1,000 rpm. Maybe I should do a 4.0 throttle body and it sounds like all that will be automatic
Hung like Einstein and smart as a horse...
have you tried using the 4.0 IAC? Interchange them see what happens. I did this 4-5 years ago, and I know I sorted it out with the parts and sensors from the two throttle bodies. It turned out great and gave me a little more pep. However moving to the Seattle area at sea level made just a little more difference.