Spectra Fuel Sender

[Fast355]

I called dealer who I use through work for almost everything, they are one of the few dealers I know that is really fantastic. They are a little more than Rock Auto for a Delco unit, but they have it on the shelf and are 10 minutes away so I am going to grab it today.

The wiring on the Spectra unit seemed good, but the connectors are very cheap and were bending as I was messing with them. The power wire on it looked heavier than the replacement harness that came with the pump, and I cut the power wire to verify that it just wasn't heavy insulting, which it did actually have a heavier gauge wire. I used a Spectra tank which seemed really well built, I'm disappointed in the hanger though. I have a Carter pump from Napa which I bought because it is made in the USA. I already swapped the pump out under warranty, but I did notice the old pump had a bit of a growl to it and vibrated a lot more than the replacement I got, the design looks a just little different. Maybe it was drawing too many amps and melted it down.

Its more likely that it is bad wiring causing the pump to draw too many amps. To make the same power on less voltage the pump will draw more amps. I recently installed a new pump in the 97 Express. Found out that the pump was still not pumping enough fuel at WOT. The capacity of the pump should have been adequate for my engine. Checked a little closer and I was running at 3-4 volts under the alternators output. Added a Racetronix fuel pump Hotwire kit that powers the pump directly from the alternator via a 10 gauge wire and 30 amp relay and upgrades the fuel pump to chassis ground at the same time. With proper voltage I have more fuel than I know what to do with.

[BLG355]

Its more likely that it is bad wiring causing the pump to draw too many amps. To make the same power on less voltage the pump will draw more amps. I recently installed a new pump in the 97 Express. Found out that the pump was still not pumping enough fuel at WOT. The capacity of the pump should have been adequate for my engine. Checked a little closer and I was running at 3-4 volts under the alternators output. Added a Racetronix fuel pump Hotwire kit that powers the pump directly from the alternator via a 10 gauge wire and 30 amp relay and upgrades the fuel pump to chassis ground at the same time. With proper voltage I have more fuel than I know what to do with.

Which pump and how much pressure do you run? This is something I should probably do.

[BLG355]

The differences between the GM hanger and the aftermarket are totally amazing. I was hoping I wasn't overpaying, but it's worth the extra money for the GM one. I have found this with tons of things over the years, but I didn't think a fuel pump hanger would be that important. The ohms are acutally better too in the level sender. The Spectra would read 102-105(it varied each time I ran it up and down) full, 8-8.5 empty. The GM unit reads 90.8 full and .4 empty, so much better, especially on the empty side. The gauge of the steel is almost twice that of the Spectra and connectors, wiring, and terminals is all of real quality. I might do what Fast355 did and run a separate relay right off the hot post up front, but I am pretty convinced the Spectra is junk, especially after comparing it to the GM hanger. I took some pictures of both side by side, I will post them tonight.

[BLG355]

Back up and running!

[Roadknee]

Barry - did you end up buying a hanger for the '95 or '96? Have a P/N?

[BLG355]

I got it for a 95. P/N 19111396. Some websites says it works in various vehicles up to 99 but I know they changed in 97 to the plastic stuff. I just hope this one holds up better. Everything on it seems a lot better so I hope.

BLG

[Fast355]

Which pump and how much pressure do you run? This is something I should probably do.

I am running a Delphi pump for my factory application (1997 G1500 Express 350), upgraded the fuel lines from the crappy OEM hard plastic to AN and run the marine regulator at 62 psi.

[BLG355]

I finally got around to finishing my fuel pump. I replaced the pump, and the hanger. I ran a 10 gauge wire back to a heavy sealed Hella relay. Out of the relay I got a 12 gauge wire going to a weather pack adapter harness I made, which then steps down to the 14 gauge wire that feeds the pump itself, which the 14 gauge and 12 gauge wires might be 2ft long total...my main goal was to have the main 10 gauge all the way back to the relay. It don't think it would be worth messing with the original harness on the hanger because it was so short, and we don't stock 10 gauge wire terminals at work for weather pack, but I think it will be fine.

So now the old main power line that used to fed the pump triggers the relay, the gauge sending unit wire are straight through, it was fairly easy to make, including the relay, I have maybe $35-$40 in it. I also upgraded some of the ground wires that run to the frame and engine, I think I am going to make a new ground wire coming right of the battery. Right now it still has the original 20 year old cable, which is only 4 gauge that runs to the engine and then a 10 gauge or so that goes to the fender. I want to run a 2 or 4 to the engine, and the frame, and maybe a 6 or 8 to the body. it's probably overkill but I always like heavier cables than needed.

Thanks again for everyone's input!

BLG

[355chev]

I had a bunk sending unit as well that was causing all hell. Replaced it with a Dorman and also made dedicated grounds to chassis, and put a Quick Fuel Hotwire kit in it.