hi all, i am a mechanic and have my own shop. its small, just me and my tools. i consider myself to be very good at what i do so this one is really hurting my pride. i am working on a high school buddys 03 gc sport 3.8l. a couple months ago he said it died and then wouldnt shift (limp mode) but it came out of it and hadnt done it again till a few weeks ago. when it dies, it will fire and die, dire and die, and so on till it runs rough for awhile then clears up and runs fine. sometimes it will be in limp mode not always. the pcm had a 0700 code and the tcm was a 0725. i put a ckp in it, no luck. then a cmp and fuel filter (just cause it had never been done--145K) still no luck. when my scanner (genisys) wasnt helping, i tapped on the pcm while van was running and it stumbled. any time i tapped the pcm it would make the motor miss. so i got a reman from acx in florida. still acts up. i figured out that when it doesnt start, if i unplug the tcm, it will start right up. thinking i had it this time, i got a reman tcm from acx, and the stupid thing still acts up. on a tip from another mech, i replaced the solenoid pack, still dies. i have wiggled and twisted any wires i can, no luck. checked all connections, flipped the fuse/relay center and checked, no corrosion. if anyone has some insight, i would greatly appreciate some help. right now, i dont have a direction to look.
thanks again, john
btw, i have gone through almost 100 pages in this forum searching and havent found a solution.

 

Welcome to DF
One of the problems that most of the members are seeing, is the wires going around the power steering reservoir and the rear cylinder head. Open the wire harness and inspect the wires. There could be some wires melted together. The P0725 code is for turbin speed sensor. Input and output speed sensors.

 

thanks mt, my scanner told me that the 0725 was an "engine speed sensor" or ckp. i have ordered both the input and output sensors from rockauto and will get them tomorrow. till then, i will take a close look at the wires you mention (i have wiggled and pulled and twisted all of them i can reach) but i have seen this melted wires thing on a similar van (02 t-c)