Help

I swapped in a 94 5.8 into my 92. ECM was changed out to the 5.8 one. Air pump deleted with egr still hooked up and vacuum solenoids plugged in but no vacuum lines hooked up.

It runs REALLY bad. Idle is around 600-800. Missing really badly. If I try to gingerly rev it up it will only go to 1500 rpm......

1,3,7,2,6,5,4,8..... New wires, cap, rotor, and plugs. Fresh gaskets from headgasket on up. New set of roller lifters (94) OEM. Timing marks are on 10 btdc with grey plug out over by module.

Both trucks ran great before the swap. Just my 92 had 400,000 kms and finally threw #5 out the side.

 

Did you use a distributor for a 92 5.8? I think there is a difference in the ignition control modules, bit somebody smarter may come along and correct me. But to start try this

 

Mudsport is correct about the different ignition control module.

The '92 uses a grey one and the '94 and up use a black one.

Yes, they are different, not just because of color. Subford has noted this many times and most Ford parts guys will tell you there is no difference. There is.

Disconnect the battery, swap them out, and be sure the power has been disconnected long enough to clear any residual power from the PCM so you can give it another shot.

 

And hopefully you didn't use any wiring that came with the 5.8.

 

My guess on this is that if he didn't go mass air the 94 roller cam. I was under the impression on mine that I needed to stick with the flat tappet 92 camshaft or risk pissing off my Speed Density computer.

A side note, I had no difference in the way mine ran between the 5.8L wiring harness and the original 5.0L harness. I just did the same swap but to a flat tappet motor. Mine has a slight miss but I think its the old injectors I used. Everything else is new on mine.

 

No the 351w roller came in Speed density trucks and run just fine. My 95 F250 is a 351W speed density.
Trav

 

If both trucks were SD and the same year or close then the engine wiring harnesses were the same. In the OP's case it's possible the '95 truck was MAF(if it was a 1/2 ton) and that engine wiring harness is not at all the same as the original SD harness in his truck.

 

Yes, I agree with that completely. I was more thinking maybe the roller cam is from a MAF vehicle and not speed density specs.

 

Same OE camshaft, unless replaced.