4.0 swap engine ID please help.

[yodaman1151]

Got this 85 with a 4.0 OHV swapped in and started tearing it apart having to fix the alternator wiring and some other stuff. Well it will run fine for about 10 minutes till it gets warm (I think) then it loads up and chokes itself unless you give it throttle. Now I went to the JY today to look at motors cuz mine has what I think is a cam sensor in the back wher the dizzy should be but the wiring harness didn't have a plug. Well the behind the motor harness was behind the radiator and I found a plug that didn't fit anything. Figured out that was for a MAP sensor? Looks like one anyways. Plugged that in and runs crappy almost always. And I can't plug the IACV in or it will idle at 2k rpm. from what I gather is the motor and wiring are not from the same vehicle. The motor is at least a 93 and the wiring is prior to that. And no I haven't checked the ECU.

My question is: Should the motor run without the cam sensor if the wiring and ECU don't need it? Basically can you run an older harness on the newer motor? Any suggestions are very appreciated and really needed.

Thanks

 

[DangerRanger94XLT]

Have you also checked the MAF? My 3.0 would run fine and then it would idle rough and soon die because mine was warn out.

 

[holyford86]

Pics would be nice, Have you scanned for DTC codes yet?

 

[yodaman1151]

Maf I believe works alright cuz it will pretty much just die when unplugged. Plus it's like the third one that has been in it. It has issues randomly. It was cold this morning so I started it. Ran crappy for a while then die so I kept starting it. Randomly it started up and ran fine one time... I don't get it. drove it around for bout 30 minutes ran pretty good but just had a slight miss here and there.

Not sure if the DTC is hooked up or not. I'll research it and find out if it has codes

 

[yodaman1151]

Checked the maf and voltage all looks fine. Tried to check codes and it apparently isn't functioning cuz I didn't get any codes to come out of it. Found that the motor has to be from a 93-95 cus it has a cam sensor but the wiring has to be from earlier cuz there is not a plug for the cam sensor. Not positive it's the right computer so I'm gonna get a complete wiring harness, computer and dash from a vehicle that has the same motor and trans which is proving to be very difficult since I'm searching for a 93-95 4.0 OHV manual trans without egr or dpfe... I have the most elusive 4.0 ever I guess

 

[Snoranger]

What computer are you running?

It sounds like you have figured out the approx year of the engine and wiring, but never even glanced at the year printed on the computer. Did you know the early '90 4.0l used 16lb injectors and newer ones used 19lb?

For the most part, a newer engine will run fine on an older computer and harness. (I'm running an '01 SOHC on a '95 OHV computer, so anything can be done.)

 

[yodaman1151]

I did not know the injector thing. I wonder if that's the issue cus it runs stupid rich all the time and I'm wondering of they aren't sticking cuz it misses a little but new plugs and all are Gettin spark. Does anyone know where to look online to figure out what year my computer is out of?

 

[F150hybred]

This might help you in your search... it does have a lot of information in it.. most is irrelevant to the 4.0. But it should help you.

http://www.oldfuelinjection.com/

This page should help explain what's happening and why.

http://www.oldfuelinjection.com/?p=3

And this one should help identify what computer you have or need.

http://www.oldfuelinjection.com/?p=17

 

[Snoranger]

I did not know the injector thing. I wonder if that's the issue cus it runs stupid rich all the time and I'm wondering of they aren't sticking cuz it misses a little but new plugs and all are Gettin spark. Does anyone know where to look online to figure out what year my computer is out of?

What is the part # on the computer?