ok BJ,sunder.... and thos ei have forgotton .... I just bought a 4.0 efi to replce the tired old 4.2 carter carbed POS..... ok so i was doing some reading .... and i assume im gonna need a different fuel pump to accomodate the pressure needed for the EFI correct?? if so do i nee to change the tank too? or just change the lines and upgrade the pump.... i will be making the change this spring and want to cover all my bases... and yes its complete <img src="/forums/images/graemlins/nana.gif" alt="" />

Check here:

www.cjoffroad.com

They have a forum strictly dedicated to swapping in a 4.0L engine into a CJ. Do lots of research on that site as pretty much every single problem that has come up has already been posted and answered several times.

Good luck with the swap, you won't regret it, ever.

Chris

Another quick write up http://www.4x4wire.com/jeep/tech/engine/fi40swap01/

good write ups guys...pretty self explainatory.... but because i am using yj to yj motor swap i assume i don't need any of the adapters that was mentioned in the 2nd article... all i see that ill need is the new fuel pump,map sensor,CPS, o2 sensor,and speed sensor......... heres my other idea...my 4.2 has only 100,000 miles on it and runs fine if and when i can keep the carb from acting up... would it not be easier to just sawp heads and efi and be done with it.. or is the 4.0 swap just that much better... im not inna hurry but would like to have it running good before summer..... the big reason for wanting to go with my sencond option...1 for ease 2 id rather keep that 4.0 out while i save up to stroke it and then do an intire swap ..... what do you guys think <img src="/forums/images/graemlins/cheers.gif" alt="" />

i feal like i answered all my questions while i was typing HAHAHAHAA well id still like some input <img src="/forums/images/graemlins/nana.gif" alt="" />

Swapping heads will be twice the work. not only do you still have to set up the EFI, you also have to pull the head get some machine work done to it and put it on the 4.2. With the higher compression of the 4.2 you'd also have to run higher octane gas for it to run right. If you want it running well and soon just put the 4.0 in.

The fuel pump needs to able to supply a constant 40 PSI. You could either buy a 4.0 tank and pump, or put in an aftermarket pump.

thanks sunder that makes sence... ill go the other route <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/patriot.gif" alt="" />

When do you plan on going stroker? You are going to need to get at least the pistons out of the 4.0 which will require the head to come off. It might be to your advantage to just get it all done right now.

ok sunder its like this.... all i want outta the jeep right now is to run good... its hard to do with the setup i have thats why i bought the 4.0 donor... now down the road ... and i mean way down the road im gonna combine the 2 to make a stroker.... but as of right now it seems just swaping the 4.0 will suffice... im not a power junkie... i have never really needed more power from my jeeps(s) engines... just this is my 1st with the carter BBD and i hate the way it runs ... so this upgrade seems to be a smart move... allthough there are some different set ups going on.... i used to be that "rich" kid that never had to worry now "im the working man" that has to pay ..... i want to best result for what im doing or trying to do...... i have a 90 YJ with a carter.........and i have a 93 EFI from a YJ just sitting ... it came froma friends jeep thats still running<<< so yes its a good core... I just want to know whats the best optional upgrade ..... i kinda know what to do ... i just want my damn jeep to run..... i live in dallas and whilemi can go for a different carb it will not pass inspection... its not my DD but i still want it street legal <img src="/forums/images/graemlins/butwiggle.gif" alt="" />

If you want it to run well and dependable, put the 4.0 in it then keep it as stock as possible. The more you modify it the less dependable it will be.

thats the plan..... i never like to modify anything ... within reason .... no need to for what i do... just wondered if i should do the motor swap or head swap ... that is all <img src="/forums/images/graemlins/cheers.gif" alt="" /> ohh hey BJ im gonna tow the heep down and use your garage to swap!! thanks in advance <img src="/forums/images/graemlins/kewl.gif" alt="" /> oh yes ill bring the beer~~~!!! <img src="/forums/images/graemlins/cheers.gif" alt="" />