What's the difference between 91 and 93 4.0

[junkb2000]

Currently I have a 1991 4.0 out of an explorer in my BroncoII I also have a 1993 explorer sitting in the yard with a bad tranny. Th e motor in my BroncoII has a tap that keeps getting worse. What I want to know is can I unhook all the electronics from the 93 and drop it into my truck with the harness that is in my B2, or will I need to swap ecu's and harnesses what is the difference between the 2 if it is gonna be to much hassle I am just gonna get rid of the 93 and find another 91

 

[MAKG]

It's never advisible to cross electronics between model years; at the very least there may be calibration issues. It's technically (and perhaps practically) illegal to do it that way, as well. I see two reasonable choices here:

1. Swap the whole emissions system.
2. Swap the long blocks.

Either one should work well and be completely legal, though your state may require some (minor) hoops to get #1 legal.

 

[junkb2000]

I will probably keep the long block as you said and hope everything works out

 

[AllanD]

The only things actually different on the 1993 Vs the 1991 are:

The 1993 engine is intended to run with Dual HEGO sensors
(but the HEGO sensors are mounted to the Y-pipe)

The 1993 has DIFFERENT (not necissarily better) injectors

SO... if you just swap your 1991 injetors onto the 1993 engine
everything else on the engine will work fine

I would recommend swapping out the Alternator bracket and water pump pulley for the different pieces used on thw 1994-up 4.0's

the early tensioner is harder to remove and replace the belt than with the later bracket and tensioner.

As for the Power steering pump bracket? Use the 1993 piece instead of
the 1991 piece.

the 1993 will have tubular dowel s between the bracket and the A/C compressor
these locate the compressor more positively.

AD