4.0 Head and MPI Swap runs for 2 seconds only - Need Advice

[DirtyB]

So I went ahead and did the swap. I'm really frustrated because it runs great for all of about 2 seconds and then kills itself. I NEED HELP!

I took the head, intake, wiring, and sensors from a 1994 Jeep Grand Cherokee. I installed on a 1981 CJ-8. I used the crank shaft position sensor from Hesco on the balancer, and it appears to be working OK. I also bypassed the security system by tieing the white and purple lines together. I grounded the Park switch to fool the computer. I installed a new Grand Cherokee generator (alternator) with a V pulley.

It's running great except that the computer is killing the system. I'm very confident that it's the computer doing it as the fuel pressure is good. When I monitor the voltage to the coil and the injectors, they continue to have power even for a split second after the engine has completely stopped turning. However, if I monitor the ground on the injectors and coil (controlled by the computer) it goes open and stays open approximately 2 seconds after starting.

Does this have anything to do with the cam shaft position sensor in the distributor? I ask this because there's some diagnostic sections in the shop manual that talk about certain voltages staying on for only 2 seconds. It has something to do with the cam shaft position sensor

Am I going to have to cough up some bucks and have my computer flashed?

I've never worked with fuel injection before, so I'm lost...

[DirtyB]

Got it! Bad computer. Runs like a champ now except the fuel pump sounds like it's not keeping up or maybe it's sucking air.