carburating my 89 4.0 xj

well my pats jeep is just sitting at my dads shop and its in good shape other than a few dings and it being completely stripped. well he wants it out of there and i was thinking of carburating it and deleting the ecu. im almost too far gone on putting stock parts in and i dont really want to since it will never hit the road again. my question is would it be easier to swap a 258 intake on my 4.0? or can i modify my intake for a carburator?

First off, you will never pass smog. It would probably be easier to go to a JU and pull a full wiring harness and ECU and swap it over. Carbs suck on the trail. Around here we have too much altitude change on trails and too many off camber obstacles.

I don't need it to pass smog. And its not going to be a trail vehicle. Its 2wd 5 speed. I don't want a computer tho. There is no messing with the renix years ecu unless u have thousans and are a genius. I'm not too sure wat the use is gonna be for it but I know I'm not gonna climb rocks in it I already have one for that.

^ you sir are a moron.
Everyone always complains about the renix jeeps and I've owned three, they are dependable and easy to figure out. All you need is a volt meter and a spare CPS in your glovebox and they will go 300K plus

that being said its your jeep do whatever you want. IM sure you could make an adapter plate for the stock intake and stick a carb on it, you are going to need a different fuel pump and probably a hole cut in the hood but sure go for it

2wd jeep not ever driven on the street or offroad? What the hell are you going to do with it?

He said it doesnt need to pass smog. That doesnt mean it wont be driven on the street...

"Since it will never hit the road again", guess he did say that?

Alright. First of all I'm not complaining about reliability or anything I have a 88 xj that has over 300k this is my parts jeep I just wanted somethin simple as hell and I would be able to make my adjustments with a turn of a screw rather than having a untuneable computer.I'm not sure wat my use is for it yet I might even put my spare front axle and transfer case in for rally.

The Renix system is pretty simple and out performs a carb in every aspect.

Also keep in mind once you get the carb bolted to the engine you still need to find a different distributor since the computer runs that too.

Well I guess I don't really have a reason to want it other than doing it to work on with my dad since he literally won't touch anything that has crazy vacumn lines and sensors on it. I don't really have a problem doing it since i literally stripped everything off this jeep and put on my 88. Well should I go with a 258 intake? I understand I need a new distributor and a low pressure fuel pump. But I was wondering wat would be done with the crank sensor?
And stop thinking I'm so crazy carbuerators aren't horrible. Nascars don't have any electronics in them.

You'll have to pretty much engineer the entire fuel system on the engine as well as the ignition system. Personally, I'd be very happy to never run a carbureted engine again.

the forum is pretty strict on not removing emmissions equipment, this would fall under that category.

Have a buddy with a Cj-7, who just converted to FI, he loves it and he is one of those old school carbs forever type guys.

If you insist on moving forward, treat it like a 4.2, & tune for the displacement difference

IIRC, 2011 was the last year of carbs in NASCAR.

If you put on a carb and old school distributor the crank sensor will no longer be needed.

just seems like a lot of work for backwards results, but to each their own

what in the...? :wow:

There's a lot of :gee: logic in this thread. I guess it would work, but I think you really should just pull the drivetrain, suspension, and axles, then use angle iron to attach the body to an old chevy blazer frame with a 350/350 combo on it. That'd be more in line with what you seem to have in mind.

If the engine is a runner, put it on a dolly and save it for the someday when you need it.

All the smog issues aside...

Not sure how many of the 4.2L parts would swap.

You could make an adapter from the intake to a Carter BBD to take care of carburation.
And you still need to full the injector holes so you don't get a vacuum leak (drill/tap/ pipe plug).
Then make linkages to the throttle, and kickdown for the automatic if it's so equipped.

Then there is fuel delivery. Carbs take 6-7 psi max at the fill valve seat. Any more than that and they overfill, so your fuel pump will need to be changed to a 6-7 PSI unit.

Now on to ignition. You will have to get a distributor with either a points setup with vacuum advance (Standard coil), or a reluctor and vacuum advance (Electronic ignition) to make this "old school" (aka up to 85' or so ).

In the end, you will end up with a 4.0L that runs like it's that time of the month.
Best off to trick the old system into doing what you want it to. There are folks running 12's in "Stock" XJ/MJs in NHRA competition, so it can be done; I've witnessed it.

As for the Dad problem I know the feeling. I had an Uncle like that with radio. If it wasn't tubes, he was confused. You just have to encourage him to keep up with the times if he wants to do much more than add fluids. Even an oil change isn't simple anymore. The new cars you need to reset the oil timer and even the folks at Quicky Lube don't know what to do with that one since it seems like they are all unique to the Make/Model

Good Luck!

kastein said:

what in the...? :wow:

There's a lot of :gee: logic in this thread. I guess it would work, but I think you really should just pull the drivetrain, suspension, and axles, then use angle iron to attach the body to an old chevy blazer frame with a 350/350 combo on it. That'd be more in line with what you seem to have in mind.

Click to expand...

Bingo!