1996 Lumina 3.1 fuel filter

[jeffcoslacker]

Originally Posted by Schurkey

The wire harness on the sending unit--inside the gas tank--is a known and common problem for many GM vehicles. New fuel pumps often come with replacement wires for the sending unit harness. Be sure to inspect the sending unit harness visually and with an ohmmeter.

You know, I hadn't thought about it, but I wonder if this is actually the problem I've been hearing with aftermarket pumps on these older GMs...I haven't experienced it, but been advising on several at a distance where they put in an Airtex replacement and it still wouldn't run, or failed very quickly, then replaced with a GM OE type and the problem was gone. Wonder if the harness was actually the problem, and the Airtex didn't include that? Hmm.

[Schurkey]

Originally Posted by jeffcoslacker

You know, I hadn't thought about it, but I wonder if this is actually the problem I've been hearing with aftermarket pumps on these older GMs...I haven't experienced it, but been advising on several at a distance where they put in an Airtex replacement and it still wouldn't run, or failed very quickly, then replaced with a GM OE type and the problem was gone. Wonder if the harness was actually the problem, and the Airtex didn't include that? Hmm.

It probably varies with the application. I originally bought an Airtex 3210 for my pickup. (The Camaro TPI pump is often substituted for the low-pressure pump originally specified in TBI applications.) The 3210 has the four wires of the harness included. I decided I would not install a Communist Chinese pump, so I sent it back and got the AC-Delco EP241, which at least at that time was made in the USA and only about ten bucks more than the Airtex. The Delco pump also included the harness.

As I said, the harness is a common but not predictable issue. My truck was JUST STARTING to melt the power wire to the pump, and it's got 300,000 miles on it (I put 125,000+ on it, I don't know the service history prior to 170K)

[conflag98]

Here's a trick I learned while dropping a gas tank by myself. The two hoses that lead into the back of the tank, one the filler tube and one I guess the overflow tube, are very hard to get off. One, the filler tube, looks like a radiator hose, and the other is smaller. They are nearly impossible to get your hands around to twist free once the clamps are loose, and of course you are blocked trying to move the tank forward so they can slide off. I was afraid to just let the tank drop and hope they popped off for fear that they'd actually break off the tank with the connections still intact. Those things were DIRTY and were very stuck. Here's what I did: I took an old Buffalo screwdriver with a thin blade and bent it 90 degrees about an inch from the tip. (I'm sure they make a tool for this but I didn't have one) I had just enough room to get the tip between the hoses and the tank connection and break them loose at least an inch in. I slowly lowered the tank, a little at a time, then returned to the back of the tank and kept pulling on the tubes every time I did it. The large one came right off as I lowered the tank, but the smaller one was very long and very stuck and wouldn't slide off. I was also thinking of the job I was going to have lining up both of these tubes, in addition to the two vacuum lines on top of the tank, while still lifting and securing the tank on re-installion. There is a hole in the cross member of the rear suspension where the smaller tube is exposed pretty well. I reached up through there with large cutters and snapped it in half and the tank was free after a couple more lowerings and some more pulling on the filler tube. Once I got the tank past the exhaust this was easier, as I could also move it slightly side to side. When I went to put the tank back in, I put a new piece of line on. (with a clamp, which it didn't have, and I was also afraid it would fall off while I was putting it in) I left the line deliberately long, so when I put the tank back in all I had to do was stick it through its space and let it hang. Once I got all the other tank lines reattached and bolted the tank back up, I went to the back, lined that smaller piece up with the metal piece it connects to, cut it to the length I needed and clamped it. There might be an easier way to do it yourself, but I couldn't figure it out and thought I'd share this. Thanks for all your help!