4 cyl. to v8 swap what wiring

[jeremey thomas]

on a 4 cyl to v8 swap,fuel injected,do i just swap the engine harnesses and computer or does all wiring have to be changed?need help and advice

 

[jeremey thomas]

nobody knows how to do a fuel injected swap!

 

[TC93]

Mainly just the engine harness needs to be changed and add the 02 and injector harness. But depending on what year car you have and what year harness, a dash harness may need swapping.

89 engine harness are compatible with 87-89 dash harness. Have 2 plugs(grey & black) where it connects to the dash harness behind D-side strut tower.
90 engine harness will only work with a 90 dash harness, Also has 2 plugs (grey & black) where it plugs into the dash harness, but also has white plugs for the air bag sensors.

91 engine harness will only work with 91 harness. Has one plug (reddish-brown) where it connects to the dash harness.

92-93 engine harness will work with 92-93 dash harness. Also has one (reddish-brown) plug where it connects to the dash harness, but also has the fuel pump relay close to the mass air meter plug.


The 90 engine harness looks like the 89 but has (white) plugs for the air bag sensors. One will be by the mass air meter plug and one on the side by where the headlight harness plugs in. It will plug up to 87-89 dash harnesses but won't work without some re-wiring. Trust me learned the hard way, tried a 90 engine harness in an 87, and had no fuel pump action. Soon as an 89 harness was swapped int he car fired right up. Has to do with 90's and the air bag set-up.

91 only works with 91, because of location of the fuel pump relay. In 92 it was moved from under the driver seat to the engine bay. But the 91 engine harness look the 92-93 harnesses. There is only one plug where it connects to the dash harness behind the driver side strut tower.

 

[bullitstang1313]

You also need to check the alternator connector, I don't remember what years were different off hand, but some of the alt connectors were different. Or you can just upgrade to a 3rd gen alt now and eliminate the need if you decide to go with an electric fan, stereo, etc.

 

[NFGTragedy]

You also need to check the alternator connector, I don't remember what years were different off hand, but some of the alt connectors were different. Or you can just upgrade to a 3rd gen alt now and eliminate the need if you decide to go with an electric fan, stereo, etc.

The alternator wire will need to be extended as on the 4cyl its on the drivers side and on the v8 its on the passenger side and it will not reach over the top of the v8. It did appear to be the same connectors from 4cyl to v8 on mine though. I just did the 3G upgrade with a piece of harness off the 3G setup and spliced it in behind the ac unit and ran the new hot around the front like how the v8's are run. It works great.

 

[TC93]

The alt wires can either be extended or swap the harness out for a V-8 one. When doing a 4-8 swap years ago, we just lengthened the wires and never had a prob.

 

[MrKwik]

The alt wires can either be extended or swap the harness out for a V-8 one. When doing a 4-8 swap years ago, we just lengthened the wires and never had a prob.

I just extend them for carbed 5.0 swaps. If memory serves, the alternator wiring isnt in the main engine harness but in the harness that has your headlight wiring. You would have to swap that too if you didnt want to extend the alt wires. The connectors from a 4cyl alt to a v8 is the same though.

 

[afast93stang]

The alt wires can either be extended or swap the harness out for a V-8 one. When doing a 4-8 swap years ago, we just lengthened the wires and never had a prob.

I did the same thing with my swap back in 2002 and this car is my daily driver. I also used an 89 donor car and had to get a 93 engine harness. It can be done!

 

[TC93]

I also used an 89 donor car and had to get a 93 engine harness. It can be done!

It can be done, but allot simpler just to get the year hanress needed, IMO. Heard all the is needed is some moving of pins in the EEC connector, but not sure which ones. I never really got into that when doing swaps, but would like to know though. How didi you go abput using a 93 harness with the 89 dash harness???