So far, I have a small fortune into fixing this / related problems. I’ll state what we’ve done and what is currently happening. I’ve taken it to my normal mechanic several times, I’m looking for additional opinions because they basically have no idea. This is on our 2003 Chevy Tahoe, my wife’s daily driver, and what my kids are normally riding in. It only has about 60K actual miles on it and is a flex fuel model, if that matters.
Originally, the truck would have trouble starting. Cranking, but no ignition. Waiting a a few seconds, try to crank again and it would start up. This went on for about a week and then it stopped cranking cranking at all. Had it towed to our mechanic. PCM B fuse was blown. Replaced PCM B Fuse (20A) and it blew again after starting. It died while trying to idle. They did some voltage drop tests, seemed good. I’m not sure they did any current tests at the fuel pump which is on that fuse. Ended up there for 4 days (yes, lots of labor) and leaving with no real clue, but a 25A fuse would work.
A week later,we were still having problems (but my memory is a bit shady). The mechanic did some pressure tests and bleed tests and said that our fuel pump was outside the specified pressure and needed to be replaced. Dropped tank, replaced pump and sending unit with a new AC Delco, replaced fuel filter. Took it home, it seemed great.
Then my wife called me and said her truck was dying at every stop sign. When she got home, I verified, the tank read 1/4 full, truck would die at almost every stop. Truck would die slowing from 45 to 20 mph to make a left turn. This was dangerous, took it back to mechanic. Mechanic couldn’t find an issue, but figured it was the sending unit. Replaced the part under warranty, didn’t charge me any labor. They thought that we were really empty at 1/4 tank and had a bad sending unit, but that doesn’t seem to be the case now.
I know, TLDR, sorry. Here’s the basics of where we are:
Truck runs fine when above 1/4 tank of gas.
Truck suddenly dies when stopping or slowing down when the gas gauge reaches 1/4 tank. Starts right back up with no struggle, otherwise runs fine when tank is low…
Tank never empties. We can get a maximum of 16-17 gallons in it. The tank is 26 gal, and we previously have filled it with as much as 24+ gallons in one filling. The gauge needle barely touches F when full, and basically the car is underivable when it reaches 1/4.
I’m really stumped on what the cause may be. I’ve given up on theories and looking for opinions, theories, research papers, or GPS coordinates of a good cliff. TIA.