I just finished the e40d to zf swap. My truck is a 1995 F350 with the big 460 gas. I didn't have one whole donor truck so my parts came from all directions. I am very happy with the result except for one thing. When I push the clutch to shift up to the next gear the rpms just hang there around 2000-2300 for about five seconds and then drop off very slowly. Is this because I kept the ECU that was already in the truck? Has anybody encountered this before? It seems that when i am just sitting in the yard in neutral if I rev the engine it returns to idle normally, but when I am driving down the road the rpms don't want to drop between shifts. I assume I could just pop in an ECU out of a junked manual trans truck of the same year and same engine right? Would that fix the problem? I have called three or four Ford dealerships and nobody seems to be any help. They said they may or may not be able to reprogram my ECU because everything is based on VIN numbers. Any ideas?

 

Don't know if this will solve the problem, but if you still have the manual lever position switch from the E4OD you could try connecting just the switch to the harness plug and try fooling the PCM by placing the switch in the neutral or park position. Don't know if it will work , and I don't think you would do any damage to anything. Let us know if it helps.

 

Here's a thought...My 1988 Ranger 2.9 V6 w/5 SP manual trans would keep the RPMs up between shifts or if I put it in neutral while moving at road speeds. My 2004 Freestar with auto tranny does the same when I put it in neutral while rolling at road speeds. It's possible that with the advent of ECU's the ECU knows that the vehicle is moving (Speed Sensor) and keeps the RPMs up so that everything remains at speed lessening the shock to the drive components when the vehicle is placed into gear.

I know they're not like your truck, but it's the only thing that popped into my head at this time, but it's something to ponder.

If you're lucky, somebody with a F-Series and ZF tranny will read and post...