i've got a 1998 Ram with a blown 3.9 engine. Looking to swap in a 318 from the same generation. Basically aside from the engine what else do i Need?

I know the accessories swap over , and it bolts up to the 5-speed trans i have.

Most likely the donor engine will be an auto so can i use the V-6 5-spd computer somehow with the 318 by wiring in the 2 missing injector wires? Or is it better to use the 318 harness and computer?

Not too concerned with check engine lights or anything, i can manage that.

at the end of the day looking to do it all economically, it's a short box regular cab so should be some fun with a v-8 in it!

 

You will need to use the 318 PCM. And prob the harness too (or parts of it).

 

Ok. I found out the harness is all chopped up on the 3.9 anyways. I have a 96 Donor truck for all the ecu, harness, etc.

So I am pretty sure she'll run with the 318 Auto ecu. Are there issues between 96 and 98 trucks I need to be aware of if I am swapping in the harness from the 96 into the 98?

 

Yes. The 96 stuff won't work in the 98. Too many things changed. It isn't just a simple rewire job. You need the harness and PCM from a 98 or newer truck.

 

Ok. Great. Thanks. I heard different things that it would work but I doubted it. Is it 94-97 and 98-01 that are the same wiring wise?

Will a 318 auto ecu work? I suspect finding a 5 speed one might be a challenge?

 

94-95 is obd 1, 96-up obd 2. As HeyYou stated, 98 and up there were some major changes made to the electrical and the interior.

As for the pcm (or what ever you want to call it, lol) a 318 auto will work (with the proper year)... BUT you will have a check engine light. Only way around that is a tune or the proper computer. I'm not sure if a dealership can or will do the programing, but there are other options.

 

If i have a 98 pcm for a 318 is the wiring from it close enough to what is in my 3.9 98 truck that I can make it work . I am pretty good with wiring diagrams so if it's just a matter of wiring the 2 missing injector wires and possibly some other small ones that would easier than replacing the harness.

 

Nope. These motors are sequential MPFI. that means, it fires one injector at a time, instead of batch fire. (all on one side, or the other...) So, on the V-6 harness, you are going to be missing wires for two of the injectors.

You need the PCM, and harness from a 98 and up V-8.

 

^ and manual trans...