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akdriftr
06-28-2016, 03:54 PM
Recently acquired a cherry 1991 Mighty Max 4x4 with the 3.0 and 5 speed got it for free not running (burnt up ecm). Traced the problem to the Idle Air Control Module going bad which in turn fried the ecm. Got the ECM rebuilt and a new IAC but Im at a loss since the previous owner removed what ever else relay wise while trouble shooting that was near the ecm behind passenger kick panel. It looks like I have 3 plugs just dangling, only info I can find is a fuel pump relay possibly as well as an auto 4x4 module but these arent definitive, any help would be greatly appreciated!

Jeff V.
06-28-2016, 06:39 PM
There should only be 5 connectors in the passenger kick panel. 3 for the ECU, one for the MFI relay, and one for the 4WD indicator box. There's also a ground lug that attaches to one of the bolts that holds the ECU in.

If you've got one of the really rare trucks with power windows and locks, there will be two more connectors over there for the door harness.

I've got a 92 V6 4x4, and factory service manuals. Let me know if I can help.

akdriftr
06-28-2016, 08:01 PM
thats exactly what I count, 3 for the ecu and a ground lug, I have a 9 pin plug which the book calls the engine control relay? Im having issues finding one right now unless I should be looking for a different named part.....there is also a 6 pin plug which must be for the 4x4, do I even need the 4x4 indicator control? Thanks for responding!

Jeff V.
06-28-2016, 09:03 PM
The 4x4 box just causes the light on the gauge cluster to come on. It doesn't do anything else. The 4WD is entirely mechanical.

Looks like there's 2 different MFI (engine) relays for the V6. One for 1990, and then an updated one for 1991-1995. You should be able to get the later part number (MB906016) from a 88-90 V6 Montero, or a 91-94? 3.0 Montero. Looks like RockAuto has them for ~$65 if you can't find a used one.

akdriftr
06-29-2016, 11:04 PM
Awesome!! Thanks for the great info!! Found the relay you mentioned on ebay and should have this thing on the road soon!! These are pretty cool little trucks!

Jeff V.
06-30-2016, 08:03 AM
I'm glad to hear that. Good luck with the repairs. Mine is absolutely beat to hell, but it's still a fun little truck. I'm looking forward to making it into an interesting project.