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Discussion Starter · #1 ·
Working on another issue in another thread, I wanted to confirm what's going on with my fuel level sensor. Kinda crude, but I took out the fuel pump / sending unit assembly, then hooked it back up. When to key on, the fuel gauge goes immediately to full, (like it always had).

However, if there is a little pressure held on the rheostat, the fuel level reads completely accurate. Since the sending unit is in the trunk area I can directly watch the gauge as I manipulate the level of the sending unit.

Looks like on the rheostat there are these little prong / fingers that ride along the brass detents. Any ideas on how to make it tighter so it doesn't lose continuity? If it has a slight wiggle on it, the prongs leave the brass detents and that's when the fuel gauge jumps to full+. If I hold a little pressure against it, the gauge reads whatever level the sending unit is at, working like normal.
 

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Discussion Starter · #2 ·
Actually I was able to pop out the rheostat and gonna try bending those fingers down so they have better pressure against the rheostat.
 

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Discussion Starter · #3 ·
I can't believe that crap worked. For the first time since 2003 my gauge is actually reading correctly. Maybe anyone who is having similar fuel reading issues could give this a try before replacing the sending unit, if it's gotta come out anyway check those brass fingers are making good contact on the rheostat.
 

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Not having a working fuel gauge would bug me, even though I use my trip meter to decide when to buy gas (usually around a half tank or 100 miles).
So, for me, I'd do whatever it took to get the current sending unit to make contact.
I'd try to take the plastic float arm off the sending unit assembly. Then make a slight bend in the metal prong/finger that rides on the flat piece.
If I was able to get the float arm back on successfully, then all that I'd need to buy is the pump itself. While it was apart, I'd clean any corrosion off where the contact is made.
If I couldn't get it back on, or if I saw I couldn't get it off without destroying it, I'd look for a complete new fuel pump/sending unit assembly.

Some posters here recommend Bosch brand pumps, others have their favorites.
I have a mechanical pump on my 4.2, so I haven't needed to buy an in-tank pump.
Perhaps other more knowledgeable posters will chime in with their experiences.

Good Luck, L.M.
 

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Doggone, I went to get a glass of iced tea after I read your first post. That and I type slow.
If I had been quicker, I could take credit for advising you how to repair your gauge.

I'm glad you got it fixed. Great minds think alike.

Good luck, L.M.
 

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Discussion Starter · #6 ·
Doggone, I went to get a glass of iced tea after I read your first post. That and I type slow.
If I had been quicker, I could take credit for advising you how to repair your gauge.

I'm glad you got it fixed. Great minds think alike.

Good luck, L.M.
Lol I'm still giving you credit since you volunteered to put your 2c in 🙂

Also it's funny you mentioned it the fuel pump installed is a Bosch, gonna take a run over to Napa to see what they have in store I've always had good dealings with Napa.

Also I'm jealous of the YJ's with the external mechanical pump, seems like such a backwards move to put an electrical one in.

I'm so excited about the fuel gauge working now I don't have to wait until it starts bouncing chaotically for a signal for me to go get gas ASAP lol.
 

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External fuel pump is antique technology, usually found on carbureted vehicles. It's a "puller" for the greater length of the fuel line.
In-tank fuel pumps are usually found on fuel injected vehicles. They're "pushers" and generally produce a lot more pressure than a mechanical pump.

That said, I had a Cadillac Seville many years ago that was a diesel motor car when it was built. A PO had installed a GM small block gas engine. It had an in-tank fuel pump that appeared to work well with a carbureted engine. Some vehicles with in-tank fuel pumps that run carbs need a fuel pressure regulator.
There seems to be exceptions to most situations, but in general, a FI motor needs a lot more fuel pressure than a carbureted one.

Good Luck, L.M.
 
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