2.9L to 4.0 Swap Problems

[bigkylewhite]

Hey guys, 1st post (been lurking on here for a while). Thanks for the forum.

Long story short: Bought a '90 Ranger with a bad 2.9. Decided to do a 4.0 swap. Did our research (I thought). Bought a 4.0 with the wiring harness off of a guy and rebuilt the bottom end. The guy told me the 4.0 was out of a '92. Turns out it is from a '94. The wiring harnesses are totally different between my '90 and the '94 harness I have. The '90 has a distributor, the '94 doesn't. Plugs don't match up. So now I'm stuck. What are my options here? Did I just rebuild the bottom end of a 4.0 that I can't use?

 

[BlackBII]

The 4.0 never came with a distributor.

What harness came with the 4.0? You are going to want the entire engine bay harness. It goes from the large round plug on the drivers side firewall, up and over the engine, and then down through the passenger side firewall to the engine computer inside the cab.

 

[broncobuckinaround]

get a harness from 94 explorer or ranger with the 4.0 you will need the computer too.

 

[bigkylewhite]

The harness that came with the engine has the large white round plug that connects to the firewall below the brake booster (same as my truck). On that harness, the computer is situated very close (~6") from the white plug. The computer is attached to a long skinny rectangular mount that looks like it probably was meant to go through the firewall (my truck doesn't have a hole like this). On my truck, the computer (for the 2.9l) is tucked inside the passenger's side kick panel and the wiring for the computer goes through a small grommet below the fan blower. Also, on my truck, all of the solenoids, battery, relay box, etc. are on the passenger's side. The 4.0 wiring harness has all of that stuff on the driver's side.

Good info on the 4.0 distributor. I was not aware of that. On another forum, it said that the '90-'92 had a distributor and '93-up has the electronic ignition.