Hi,

I'm running an '87 XJ 4.0 that just tonight I see the fuel gauge is beyond pegged pointing due East. Just tanked up yesterday so this is fresh.

Did a quick search through my manuals, and wiring diagrams and with just a cursory look, I didn't find much useful yet.

Question is, is this a wiring issue, or a fuel sender issue? I wouldn't expect it would peg like this unless something shorted maybe?

Or, might it be a gauge issue?.



fuel gauge pegged Eastward

 

Sounds like your sender is shorted to ground. That makes the gauge peg past full like that. Check the wire at the sender first it's probably pinched or rubbed through. If the wire's good, the sender unit itself is likely bad. Easy fix.

 

Excellent, that's what I was expecting. I was just puzzled that it pegged so far over.

It'll still probably take me a few days to get at it.

Thanks

 

So Fuel Gauge Calibration on Renix is the opposite from '91-'96. Level at Full indicates an Open Circuit.

 

Well, intermittent.

This morning. after I started up, the gauge dialed right in. Good thing, as it's way too wet up here in the PNW to be crawling underneath.

This is going on my to-do list.

And yeah, the rig has been on a lot of dirt roads, and has hauled a lot of dog. Pardon the dust.

 

Is that odometer reading those numbers on the original engine?

 

Sure is. Only one head-gasket as far as engine work. Otherwise, just the usual, starter, alternator, waterpump...
The one value of living in the PNW, it's not a bucket of rust either. Just sunbleached.

 

IMO Renix engines (and 91-95 but Ive never owned one) are WAY more reliable and less prone to major failure than a newer one. As these jeeps got more "Chryslerized" the quality of the engine and components went way down and so did reliability. As usual, Chrysler took a good product and ****ed it up in the pursuit of profit.
I could rant for hours about this lol.

 

Yeah, ask any of my friends, I'm exceedingly proud of my old girl. I figure it's got to be one of the oldest 4.0 XJs on the road.
I had a Stellantis "jeep", only because this XJ got rear ended. While I was lining up a repair the XJ got stolen, and recovered 3 months later (can't sleep in a rig with the tailgate jammed is my reasoning). No additional damage, repaired the XJ, and still running strong. Sold the 2019 after 10 weeks in the shop in 2 years of ownership. I called it my "yellow jeep" because it was a lemon.

It would probably have close to 550 on the clock if I didn't have a pre-GM '92 Saab convertible that gets the nod on sunny days.

BTW, there's been at least 5-6 additional attempts at stealing the XJ. I've implemented a number of theft prevention since.