99 XJ fuel tank to a 93 harness

I have put a 99 fuel tank in my 88 mj that has a 93 engine and harness . It seems that the 99s had the wires run through to the computer first , then to the gauges the 93 does not . I am in need to get this wiring resolved asap , if anyone can help It would be greatly appretiated

So here I am stuck waiting to finish my flat deck because of this last little prob , after 8 month project and one of the biggest runs of the year just days away

The pump wires are the same. They are the orange and black wires (positive and negative, respectively.) Things you're going to run into: higher fuel pressure, built in regulator and filter (the fuel rail on the 93 engine has a regulator as well, you may have to do some modifications etc.) Also, the fuel level sender is reversed - the old dash gauge will expect resistance changing one direction, the new tank sender changes the other direction, so your tank will read empty when full and vice versa. 96 is the odd year out on that, the fuel level sender and gauge cluster are wacky on a 96, you dodged the bullet there.

info sources - putting this same contraption into a 96 XJ (used a 98 tank+pump+sender), 95 FSM, Joe Peters

Thanks , any wiring diagrams , I hate wiring !

Not really... I just kinda winged it (electrical engineer here.) The heavier black wire (should come out of the same rubber bushing as the orange wire) is ground, connect that to whatever frame ground you want to. The orange wire is fuel pump power, connect that to the wire for the fuel pump, I think it's orange and green on an MJ but I really can't remember. The other two wires should be the sender, I don't think it matters which goes to which since it's just a variable resistor sender, if it doesn't work, try swapping them. It should work fine without connecting the sender at all, I've been driving mine for nearly a year that way now since my 96 fuel gauge expects a completely different setup from what the 98 sender has on it and I've been too lazy to make it work right since it runs and drives.

Turns out that was already tried. I am not wiring it. Anyone else ?

scottanchee said:

Turns out that was already tried. I am not wiring it. Anyone else ?

Click to expand...

Plenty of people have put the 97+ tanks in the earlier XJs, to my knowledge no one has yet found a workaround on the fuel gauge.

I had high hopes for Kastein coming up with something, when he gets around to it.

This, however, is an option: http://autometer.com/cat_gaugedetail.aspx?gid=2456&sid=1