So now that I've driven the truck for several days since the swap I'm starting to worry about the computer compatibility. Obviously, all the the transmission related codes popped up (I knew it would and I'm not worried about it), but none of the left them check engine light on (which I'm glad about). Now the problem... When I have the truck in gear, and release the clutch, the engine drops to about 200 rpm and almost stalls, but catches itself and goes up to about 1000 rpm and then back down to the normal 600 and idles fine. At first I wrote it off as the computer had been reset cause I had the battery unplugged for a week. Every time the computer reset itself in the past it took it a day or two before it "re-learned" the truck and ran right, but it's been 5 days now that it's been running and it's still acting up (although it is running much better than the first couple days). I'm wondering if theres a program in the computer that tells it how to drop to idle when the weight of the automatic transmission is on it, and now that it isn't, it can't figure out how to compensate. Does anyone have any thoughts on this?

 

hummm. not sure. i know the manual and auto have different part numbers and stuff but i am not sure of the exact differences. i was reading an article on muscle mustang and fast fords where i guy swapped a 6 speed into his lightning and he said they were able to reflash his old computer with a new setup, but again it did not say what it entailed. will do some digging and see if i can find something.

 

The mopar performance computers are made for both autos and manuals. You might want to check them out. The easy things to check of course are the IAC and MAP sensors. I had the IAC go out on me again. These are always getting stuck, or working slow. It was casing my Idle to drop when I put it in gear. And that sounds like what is happing with yours.

 

wait that's not supposed to happen? I put mine in drive and the idle drops from 800 to about 400.

 

Thanks Crazy! I replaced the IAC valve today and it fixed it. I guess the computer is ok to keep using (except the check engine light gets tripped every so often and it has all the transmission codes stored).