I have a 94 Bronco that had a 302 I swapped it for a 96 351 w. It drove ok for a week but then it slowly started having shifting issues and would not accelerate. My mechanic didn't switch the harness or computer. Do I need to swap the harness and computer to make it work properly?



I have a rebuilt E40D 4x4 tranny

 

From what i hear..you need to switch computers

the 302 computer is set up for a 302.while the 351 isnt.

but thats just what ive heard

 

So the 5.8 motor has the original 5.0 engine harness on it? If so that is what you want. Pull codes to see whats up and if you get an all clear(code 11 or 111) then check the basics, fuel pressure and timing.

 

302 and 351w had different firing orders. That could be your problem. The H.O. 302 used in mustangs had the same order as 351w motors.

Jess

 

some 94 model 302 bronco's had mass air while others still ran speed density. which efi is on the bronco?

if speed density, the plug wire firing order is all that is necessary.

if mass air, the injector harness must match the 5.8 firing order if running the 5.0 computer along with proper plug wiring order.

i suspect you installed the correct 5.8 flexplate for the e4od.

Conanski has sound advice

 

Conanski (Paul) always has sound advice.

 

The more you know.....*

 

Mass air in these trucks only came with engines using the 351/HO firing order.

 

thanks Paul, i had forgotten about that