Need help woth a 7mgte swap!!!

[robert.beltran91]

I'm having issues with my 7mgte swap!!! Well i have a 91 na body and have an 89 motor the reason i got the 89 motor with the 89 harness and ecu (all 7mgte) was because it was grey plug and according to everything i read it's supposed to all plug up and everythimg was supposed to be fine and dandy except the tachometer was supposed to not work, big deal msd tack adaptor would solve that issue, well eveything links up fine except this one rather large square plug and this other smaller plug, i tried searching and searching but can't seem to find the answer to my problem, i have the original ge plugs that i cut off and cut the gte harness square plug and matched color for color as many wires as i could but there were 5 extra wires left over. the car cranks but won't seem to fire there is no spark and no fuel, any ideas?

 

[Dan_Gyoba]

'89 is a special case. The plugs are grey, but they're the same as the earlier yellow ones in shape. You'll need a '90-'92 harness and ECU for that. It may involve changing out sensors on the engine as well. For later years, the knock sensors were different. I've got an '87 engine, harness and ECU in my '89 NA chassis, and everything except the ABS bolted up.

For the tach, if you get the driver board from the GTE car, you can retrofit it to the existing tach in your car (Or just swap the whole thing over) and it'll work just fine.

 

[robert.beltran91]

well i have an na 87... so it should swap into that car as far as the interior harness and engine harness goes?

 

[robert.beltran91]

btw i'm still new to this site i'm not too good at navigation sorry for any double posts

 

[Dan_Gyoba]

No.

If you have an '86.5-89 NA chassis, you can use an '87-'89 GTE harness. There may be some small things, but they'll at least plug in and it will work.

If you have a '90-'92 NA chassis, you need a '90-'92 GTE harness for it to plug in directly.

The harness can be fit to different years of engine, though there may be some sensors that will also have to be swapped over, or the connectors modified.