Can I put a TJ fuel sending unit into my 89 4 banger gas tank? I am doing a 98 4.0L swap and I need the fuel regulator in tank. Figured this is cheaper than buying the whole tank. Only reason I think it is possible is because I heard that a MPI fuel sending unit for a 4.0 will work in the pre 90 4 banger gas tanks. Just trying to confirm this. Can dorfs answer this? he seems to know his S**t.

Are you using a donor vehicle? or parts?

If it's a donor just swap the tanks... if its being peiced together from parts, I assume if the sender fits.. and is the correct size, and the gagues are either '98 4.0 or compatible, it should work.

But why not just swap tanks.. heck of alot easier.. you have to drop it out to get the sender/pump in anyways.

I don't think so, at least without some modification. The sending unit for a TJ comes into the tank about a 45 deg angle. And a YJ's come in from the top. I have a new module for a '98 TJ in the garage someplace. I can look.

I agree with changing the tank. The tanks from any Mopar in that same year will work real nice. XJ's, WJ's, and ZJ's have a tank that will fit in your bed. If you wanted to keep your YJ tank, I would think about changing the fuel rail, and hook up a return line. I have a rail you could have, for freight. You would have to change the pressure regulator on it, or shim it up to 50 lbs. I should get you by.

Somebody had a nice article on raising a tank on a TJ. I want to get my axle back, and the tank is in the way.

well i suspppose putting the whole tank in is not a problem. My biggest concern is with the wiring harness. I'm terrible with wiring and the wiring that came with my salvaged 4 banger was not..how do you say...useable.assuming the everything but the new engine's harness is toast, I need to know what is the best solution to get my engine in there along with all my guages and behind the dash gismos like ignition, turn signals etc... is it possible to get a new wiring harness from a newer YJ or possibly TJ(including fuse box) that will plug into my engine harness and I could just use the wires that I need to get the guages that I need working(getting new ones of those too). Im just trying to figure out wether I need the Hesco wiring harness or not. I figure, since im replacing the entire vehicles wiring anyway, do i really need to buy the engine harness too?

PS thanks dorfs for the offer on the fuel rail, but im going to just go with the tank idea. but i would like to know how to modify the regulator to get it to 50lbs. dont need to know, just would like to know for future reference(if needed).

The first thing you need to determine is what will pass your local/state emissions law. In Colorado, you can have it certified to any year newer. If you call your Jeep engine a '95, or a '98, you will need an opernational "check engine" light. The "ref" will pull a sensor, and verify the light will come on. Doing this with a '95 sbec, the check engine lamp driver is in the pcm. A simple keyed light grounded to a certain terminal will make it work. If you use a '98 jtec controller, the check engine light is driven by the ccd buss. You will have to tear apart a '96 or newer Chrysler dash, and remove the driver. Or simply install the complete instrument cluster.
If you don't plan on hooking up your check engine light, the newer jtec should work fine. Hooking up the check engine light on one of these systems will probably keep it on all the time because of fuel tank emissions (evap system, and purge canister). This is why swapping the tank may be benificial.

As far as the dash wiring, You won't have to do anything other than stock, you can wire the injection seperate from it. Hooking up the newer ccd buss dash is super easy. On the newer jtec systems, all air and coolant temps, rpm, oil pressure, speed, and all data is sent down the ccd buss. A simple two wire hook-up. The whole dash on a JZ only has a 10 wire connector. one each for L & R signals, one for hi/lo beam, a couple of grounds, a couple of powers, some back ground illumination and the two wire buss.

so let me get this straight.if i get the harness from a TJ from the firewall back, use the instrument cluster from the TJ as well, then its just a few plugs and everything is ready to go? I would still have to splice in the ignition? Another question. the ccd buss is the computer or harness or something? the JTEC is the computer? I'll understand pretty soon. thanks

The ccd buss is just a pair of twisted wires that carry info. between the dash, the pcm (jtec controller), any body computers, tranny controllers, and air bag controllers. It is just a way for the different components to talk to each other. It also goes to the diagnostic test connector.

The ignition is already wired into the harness. It isn't just plug and play, but can be done with out too much difficulity. The physical dimentions of the tj's dash may make it hard fit into a yj. One from a '96 and newer zj would probably work easier. It is square, and the plastic can be cut to make it flush fit.

If you picked up the power dist. center (relay center) with the other "gray" connector for the pcm, you would have just about the parts to wire it up. You may also want to pick up the data connector and mount it inside.

How much of your dash is missing/destroyed?

all the guages are trash, the underdash wiring is so complex I dont know where to begin(the vehicle was stolen and striped and the guy I bought it from who bought it from the police pieced it together from another vehicle that had an engine fire. the engine fire toasted the rest of the electrical so im figuring that the electrical harness under the dash of mine was the stolen one. also the fuse box appears to have grease in it. Many of the plugs are also not even pluged in so i have no idea where they go. The dash itself is OK, but It looks terrible from sitting out in the sun. I'd like to do a custom dash and just mount some auto meter guages in there, but im open to ideas, like a zj guage cluster.