Hey:
went from a 3.9 to 5.2 and kept the original trans 42Re for now- got a 46Re waiting in the wings to rebuild,. Its a 2000 Dakota SLT club with 503,000 k on it. Third motor original rear end and trans and a lot of other parts. Wondering where I can get a code programer for the used 97 5.2 enigine cpu at. The idle is about 160 rpms over where I think it should be.(650rpm? presently idling at around almost 825). Iam thinking it needs to reprogramed to acomplish that. Gas milage is the same or better than 3.9 at 20+ mpg. with shorty headers and newly lapped valves and ported stock 5.2 heads. Cant imagine going back or even why they put a 3.9 in these trucks.So the 2 main issues are a high idle and it cranks to start a bit after running for a while after letting it set for 20 mins which I dont understand. I think it still goes back to the computer needed to be reprogramed. The only one I was able to find that would integrate with my dash was a 97 Dakota 5.2
Any help would be much appreciated.

 

I bought a '93 Sport new in 1993 and a few years ago had a 1996 extended cab 4X4 with manual transmission. Both had the 3.9 and were quite capable. If I wanted to race, I rode sport touring bikes back then. I never had a shortage of capability with the 6 banger.

 

The long crank is probably the fuel pumps check valve. They are a common failure point on these trucks. If you don't want to do the pump you can install a check valve in the line somewhere.