I have a Good 1991 4.0L Explorer engine which I want to swap into my 1994 Explorer which has a knock in the motor. Is this going to be a straight swap or are there going to be some problems that I may encounter?

I'm thinking it should be a straight up swap.

any comments welcome.....


My swap: http://home.comcast.net/~kmfrederico/

 

Nope shouldnt have any problems,that engine should drop right in.

 

Cool!!! Thought so, but it's always nice to have comfirmation.

 

Phyiscally sure it will fit but your EFI system is different. If it's a fed 1991 engine it's MFI and all 1994's are SFI. This is really no bid deal since the injectors are the same and the wiring harness should work OK. But also in 1994, all cars had EGR where a Fed 1991 will not. So you can swap exhaust manifolds and all the EGR stuff, or live with a CEL on all the time due to EGR codes being thrown if you don install the EGR system. Other thing, 1991 Fed car wont have a cam position sensor...I think. Check Autozone's web page for the wiring shcematic. If this is not present, swap the one out of the 1994 or the spark control wont work right. Brainfart - there's something else too but just slipped my mind....I'll try to remember.

 

Oh yeah. The 91 cars had a BAP - barametric air pressure gauge. 1994 did not. Since it's not attached to the engine, it won't make a difference with this conversion.

 

I have both vehicles so I will use the 94 sensors, etc on the 91 engine. Hopefully it will all work out.

 

I like the Three Mile Island Nuclear Plant joke on your website