4.0 swap with fuel injection

[resqjeep]

I am begining the collection of parts for my head swap and fuel injection conversion. Cash for clunkers has put alot of good parts out there. Everything I have read seems nobody is swapping OBD2 fuel injection, and I was wondering what the issue was? I have a line on a 96 XJ that would work perfect for the swap, but nobodys using that new of a set up. Is the computer just not willing to accept it or what? I don't want to pull the trigger and run into huge problems that others have hit too. Anybody have any advice that tried this before?

[addicted]

It is a lot more complicated then the OBD1. I am still contemplating using it in my '97 XJ powertrain swap or going with the parts from a '93 I am parting out. The OBD1 only requires 5 wires to get it running the OBD2 needs a lot more and has a whole lot more harness to thin out. If you can wait for an OBD1 do it unless you want the challenge of making the OBD2 work.

[tgreese]

No personal experience, but I recall you can work around it.

You might try searching/asking here http://cjoffroad.com/forums/forum.asp?FORUM_ID=24 - this forum is about swapping the 4.0L into CJs, but they will know about the OBD-II engines. You can also try http://www.jeepstrokers.com/forum/ - these guys are well informed on this topic.

You could skip the Jeep computer entirely and use the Megasquirt board...

[fivepack]

No personal experience, but I recall you can work around it.

You might try searching/asking here http://cjoffroad.com/forums/forum.asp?FORUM_ID=24 - this forum is about swapping the 4.0L into CJs, but they will know about the OBD-II engines. You can also try http://www.jeepstrokers.com/forum/ - these guys are well informed on this topic.

You could skip the Jeep computer entirely and use the Megasquirt board...

Almost all of the literature for the CJ swap will relate to a FSJ swap.

[resqjeep]

Fuel injection and pick up ques?

I was hoping to use the OBD2 for the diagnostic ability, but I am not dead set on it. I have heard the OBD1 was easier and I may end up going that route. I like a challenge so that doesn't scare me to bad. I have been reading some of the other post and will go back and check them again to see if I missed something. Thanks for the advice and i will keep you guys updated as the process continues. Finishing my brake work and ready to run new fuel lines soon. Going with the biggest line I can use, anyone know if the v8 pick uses a different size line then the 6?

[Chevelleguy]

V8 used 5/16 supply, 1/4 return. Don't know but it is probably the same as the 6cyl fuel line.

[addicted]

I was hoping to use the OBD2 for the diagnostic ability, but I am not dead set on it. I have heard the OBD1 was easier and I may end up going that route. I like a challenge so that doesn't scare me to bad. I have been reading some of the other post and will go back and check them again to see if I missed something. Thanks for the advice and i will keep you guys updated as the process continues. Finishing my brake work and ready to run new fuel lines soon. Going with the biggest line I can use, anyone know if the v8 pick uses a different size line then the 6?

That is the same issue I am having and I have one of each here to use and looking at the entire OBD1 harness on top of the engine I pulled the other day and the much larger mess from the OBD2 makes me want to run the OBD1. But I am still very undecided and will be until I have to do that part of my entire power/drivetrain update. If you want a CEL for the OBD2 you will need to find a place to stash the instument cluster in your Jeep as it is needed to communicate with the PCM and turn the light on.

[tgreese]

V8 used 5/16 supply, 1/4 return. Don't know but it is probably the same as the 6cyl fuel line.

Yes, 232/258 is the same as the V8s. All Jeeps are the same AFAIK - 5/16" supply and 1/4" return (if so equipped) - except for the 134cid CJs and maybe other early models which used a single 1/4" line.

[resqjeep]

Okay, so what I may have to do is take a new sending unit and modifiy the fuel pick for 3/8. I was looking at what the EFI requires and how much the pump supplies and how much friction loss I would have with the 5/16 line. I would like to make it simple, but I am a firm believer of trying to do something right the first time. Has anyone else that you guys know that did the conversion run into a problem with the 5/16 line? I know the OBD2 system needs 40 psi at the regulator so thats my goal.Back to work next week so maybe I'll find time to drop the tank then.

[addicted]

The factory fuel line from the '97 XJ my powertrain came from is 5/16" OD so I don't think there will be a problem.

[resqjeep]

Thats the answer I was hoping for. I can start making lines when I drop the tank. Thanks for the help.

[Zorm]

any up date on this? what 5 wires are needed for a OBD 1 again? I'm about to do this swap, actually the entire 4.0 engine. I have a 2000 intake and injectors I would like to slap on as well. I also have the entire incab wire harness from the 92 Cherokee, was thinking about using the newer cherokee gauges in the FSJ gauge cluster. Anyone tried this?