HELP! -Mass-air conversion.

[11secGT]

Need your advice folks; helping a buddy do a Mass-air conversion on his '885.0L convertible
(5-speed) and we used a 1991Mustang 5.0L HO 5-speed harness and 1989 "A9L" computer
and everything plugged in fine except the airbag stuff of course but the fuel pump won't come on when we try to start,turns over but no fuel??? Ideas??

[zac_f83]

the air bag and MAF/ engine wiring is separate... IIRC no?

[TWR2003]

1991 EFI harness is NOT compatible with a 1988 body harness set.

[COLD]

Your gonna need an 89 mass air harness.

[Dean_T]

11secGT,

Did you modify the wiring at the 8-pin green connectors and how did you interface the '91 SEFI main harness brown 8-pin connector to the '88 Mustang's 8-pin grey and 8-pin black connectors next to the power brake booster?

If you can help me, I think we can sort out which wires go where.

The '91 SEFI main harness connectors are similar to the '92-'93 SEFI main harness. BUT they are not exacty alike. Could you use my diagram of the '92-'93 SEFI main harness connectors and tell me what your '91 SEFI main harness has for wire color and location.

Reference the connector by looking at the open end of the '91 SEFI main harness connector and read the pin wire color from left to right and from top to bottom.



Now, please do the same thing with the '88 grey, black, and green 8-pin connectors and use the following chart as a guide. Remember you're reading the vehicle's connector and not the '88 SEFI main wiring harness so you'll have to account for the mirror affect.




The above is for an '89 so it won't match your '88 in wire color or even wire location.

Thanks!

Dean T

[86capriASC]

Why didn't you just use the '88 harness and add the mass air wiring? It would have been much easier.

[gt pony]

Why didn't you just use the '88 harness and add the mass air wiring? It would have been much easier.

+1

[11secGT]

Figured '90&'91 harnesses would swap right over since the fuel pump relay is still under the seat in those years but not in '92/'93; I've converted an '87 harness to MAF before so I guess that's what I'll do again.-Thanks all!