Im doing a motor swap. Im putting a 94 speed density motor in a 96 obd 2 truck and i cant get it to start. It runs if you pour gas down the throttle body but thats it. Everything worked %100 percent on both trucks before the swap started. I used the engine wiring harness off the 94 and i used an obd 2 mass aired 351 ecm and massair flow sensor. Its got fuel pressure but nothin comes out of the injectors. Am i gonna have to buy a whole 96 351 obd 2 engine or just a different engine harness?

 

if you arent gettin fuel, start there and work your way back. sounds like you have it set up about right, so start givin the fuel system a good once over.

 

Back probe an injector or two and see if it's getting signal from the PCM, if the injectors aren't getting the go ahead from the PCM then they won't open. You could use a noid light, but they only tell you there is some power getting there, not the nessecary voltage to actuate the injector. Find out the specs on the voltage and test with a multimeter.

 

you have to swap computers (and re pin some of the connectors. if i'm not mistaken)

WHY would you swap out the mass system for the speed density?

 

Well basically im putting a speed density motor in a mass aired truck and converting The 351 to mass air

 

all you have to do is reuse all the old parts off the old engine, the long blocks are the same.

 

You can't use an OBDII computer with OBDI wiring. Use a different computer or different wiring.

 

The old engine was a 4.9. And i cant use a different computer cause the obd 2 computer has 4 rows of pins instead of three like the others. If i put in a obd 2 engine wiring harness will there be any extra sensors that werent on the obd 1?

 

Yes.

 

to quote the movie meet the robinsons

I dont think the plan was very well thought out.