my i6 will not run properlly, i swapped in an excellent running, dayly driven 300 straight six from a 94 f--150 xl,reg cab,long box,auto,4x4; into a 95 f-150 xl,reg cab, 5.0L(cracked block), long box, 4x4,with a 5sp/OD. i have replaced the 5.0L computer,with the one from the 4.9, but it still will not run properlly,also the ballast plug in below and behind the drivers headlight, it will start up, but runs very poorlly and then stalls, i replaced the large fuel line with regulator , that runs into the fuel rail thinking that it was fuel pressure problem but there was no change in performance!!!,it has new wires,plugs,cap,rotor, good vacumm from booster, fully charged deep cycle batt., i also changed the connector end relay box under the dash, both fuse panels look identical, i used the harness from the i6-300, and plugged it directlly into the power distribution box, everything seems to be in place properlly, but it still will not run past the initial hard startup; has anyone completed this particular engine swap successfully ; and had similar running difficulties?? are the fuel pump pressure's the same for a 4.9L, as they are for a 5.0L???

 

For my behalf only, I'm going to try to condense your thread.

Removed a blown 95 5.0L engine complete with harness and computor, replace it with a 94 4.9L engine complete with harness and computor. Is that correct, Yes or No?

Nest question, define doesn't run right.

 

hi bill.yes i removed the 95 5.0l, harness(up to the power dist. box),and the comp., i replaced it with the 94 4.9L, with harness, and comp: by not running right, i mean; it will start up, but it will not idle, or accellerate at all!!, it just rough idles for 5 to 10 seconds, and then stalls, if i feather the gas pedal, i can keep it running, but it just chugs and sputters and will not climb past 1500 rpm. im still running the fuel pumps from the 5.0L setup, and im not sure if they have the same pressure as a 4.9L fuel pump, but they look identical, and both trucks had the dual tank set up!!, this motor(4.9) ran like a brand new engine when i pulled it and i drove it dayly for three years, with regular oil changes and maintenance, and i never had a single problem with it, till now!!

 

Good morning, the swap performed sounds right on track to me. Am not experienced with doing this type of swap but can't see why it wouldn't work. Double check all the vacuum hoses and electrical connections, perhaps something was induced by your efforts. Erase the computor codes and run it as best as you can and recheck codes.

A member, Just call me Sean, has a ton of knowledge with the 4.9L, send him a PM and tell him whats going on. Good luck and keep us informed.

 

thank u for your input, i really appreciate u taking time to help me adress this problem, im going to recheck all my connections again(elec&vac ), and ill proceed to erase the computer and go from there!

 

Sounds like a bad IACV.