I have an 81 bronco that has a 5.0 EFI from a 92 mustang. It is currently not running. I would like to drop in a 5.4 but I don't know if the motor mounts are the same. what potential problems could I run into in the process of doing this swap? The 5.0 motor that is in it now has a bad ring. also....one day I went to start it but it wouldn't. the fuel pump wasn't turning on and giving it any gas. I jumped the fuel pump and it works fine. could it be a computer issue?

 

Which 5.4 are you referring to? Are you meaning the 5.7 (351) V8 that came in the Broncos? Or are you meaning the 5.4L that comes in the new F-trucks? ('99+)

If you're referring to the newer one, that's a lot of work, since the bodies and engine bays are very different. Not to mention all the sensors and electronics that go with it.

 

I am thinking about buying a 95 ford f150 that has a 97 5.4L with 40k on engine. I want to put that in my 81 bronco. I will have the wire harness and sensors off of the donor truck I just need to know if the hardware will line up in the bay.

 

If that's the case, it sounds like someone's already done the work for you. The 95 has the same engine interior as your 81. If they've already modified the 95 to accept the 97 engine, it should be a direct swap with all the mounts, harnesses, etc.

 

There's a very good chance somebody is mistaken here and that truck actually has a 5.8 in it, it was still being produced in '97 for the HD trucks, the modular motors are completely different, and there are no "swap kits" to put one in an older truck. This would be a completely custom job with a lot of fabrication.

 

Like Paul says, I seriously doubt that truck has a 5.4L in it.

Unless your engine is physically broken, it would be much easier to fix the engine that's in it rather than drop a new motor in.

 

If you jumped the the pump and it started it probably isn't a computer issue. And if it's a seldom issue, i would aim at the relay rather than a fuse.