Fuel issue or what?

clark grizwald · April 8, 2016

So I have a 2002 crew cab 4x4 6' bed 6.0 with about 180,000 miles on it. I had the fuel pump replaced about June of last year. Then in early January of this year I was having a fuel gauge issue. It was showing E when I had gas and would move sporadically etc. So I took it to a different shop than the one that put the pump in. They discovered the sending unit was bad and put a new one in.

So everything has been fine for 3 months now with regards to the fuel gauge. I'm driving to work this morning and the gauge says I have 1/4 tank full. I'm on the highway doing about 60-65 and the truck starts shuttering. Every time I step on the gas pedal it doesn't accelerate hardly and and the sputtering gets worse when stepping on the pedal. I've run out of gas 2 times in about 13 years, once in this truck and another on a car. Both times I can remember it felt and sounded just like this.

Thankfully I made it off of the highway to a gas station. I put the pump in and let go of it to auto fill. It shut off at 20 gallons. I thought this had a 26 gallon tank? Maybe it shut off prematurely and could have went to 26? I was so mad and late for work already so I wasn't thinking clearly. So I got in and looked at the fuel gauge. Without putting the key in it was now reading 3/4 full. I know for a fact that the gauge never reads anything but E until you put the key in and turn it. So that leads me to believe that the sending unit that put in is acting up/bad. By that I mean when it was reading 1/4 when leaving the house it was actually E. Now without even turning the key it's reading 3/4.

So I start it up and now the needle is reading F. I let it sit for a minute or two and then put it in Drive. I left the gas station and got back on the highway and everything seemed fine now. No sputtering or shaking and the engine responds when I step on the gas with no issue at all. I made it into work and called the shop who did the sending unit at the beginning of January. They are going to take a look at it tomorrow morning.

In the meantime, I'm wondering if it's the sending unit??? It would have to be right? It's obviously not reading properly because it moved while not even having the key in the truck. I presumably ran out of gas this morning while it was reading 1/4 full right? The one thing that's throwing me off is this; if I was on dead E and sputtering into the gas station, why did the pump cut off at 20 gallons as if it was full? Was it just the pump and maybe I should have kept pumping? Shouldn't have been at least 26 gallons? Why is it now reading F if it was in fact short of 26 gallons? Should I not pay attention at all to the sending unit and what the gauge is reading?

I did go ahead and reset the trip odometer to 0 and will use that mileage based off of the 20 gallons I put in. I'll just figure 11 gallons per mile to play it safe until I can get it to the shop tomorrow morning. Don't see driving more than maybe 75 miles between now and then. I'm just racking my brain as to what it could be between now and the time the shop will look at it. From what I've explained, what do any of you guys think? Thanks

clark grizwald · April 8, 2016

update I forgot to add because I posted this in another "unfriendly" forum and this happened yesterday.

So I make it into work. I get off yesterday afternoon and start the truck up. Everything seems fine, going through the city at speeds of around 30 to 35, get to the on ramp to the highway. Still, everything is fine. I start to get on the on ramp an start to accelerate to get up to 60 or so. The problem starts again! A lot of sputtering and shaking and the truck will hardly accelerate when stepping on the gas. I just keep it at 60 with even pressure on the gas pedal praying I can get to a different shop near my house. This is the shop that replaced the fuel pump last March. I make it there about 10 miles away and pull in. The truck was doing this issue the whole time there. Go in and speak to the guy and left my truck running for about 10 minutes.

Go back out and he has me step on the gas a few times hard while in park. No notice or indication of any sputtering or failure to get the RPM's to jump up. So we go back in for another 15 minutes or so and I left the truck running. Planned to drop it off Friday morning and he said the fuel pump and sending until was under warranty. They will run a pressure test, etc. to see if it's possibly the fuel pump.

So I leave the shop and get back in my truck. I go to leave and accelerate and the truck runs FINE. Not even the slightest hint of a problem. All the way home about 4 -5 miles and got up to 45-50. I park in the driveway and leave it for about 5 hours. Go out about 8 pm to drop it off at the shop last night for them to look at today. The whole way up there from my house the truck drives fine AGAIN! No issues at all...I drove slow, hit the gas hard at least 5 times, got up to 60-65 no issues. Stopped at lights and accelerated no issues at all.

I am totally baffled as to what this is.......Maybe the fuel pump is in the process of going bad and that's why this is happening intermittently? Then it crossed my mind......Could it have been water in the gas/bad gas and it's working it's way through the system? I always fill up with 93 at a BP station. Never off brand and NEVER anything under 93.

Just trying to put the pieces of the puzzle together. So at first I though the sending unit was bad and the 1/4 full showing on the gauge was really an E reading but then it took 20 gallons to fill it up. If I have 26 gallon tank and it only took 20 to fill up, then maybe the gauge was really right and I did have a 1/4 tank and running out of fuel wasn't the problem. That would make sense. I'm also kind of throwing that theory out because after putting in 20 gallons of fuel, it started doing the same thing yesterday afternoon while leaving work.

If it was a bad fuel pump, wouldn't it be doing this every time I started the truck? Or, if it's just starting to act up would it really be intermittent like it's doing now? I thought maybe it only happens at highway speeds and heavy acceleration like getting on an entrance ramp but I disproved that theory last night on the way to the shop by heavy acceleration and getting up to 65.

I mean, now I'm leaning to water in the gas or bad gas. What do any of you guys think after reading all what I just wrote?

clark grizwald · April 8, 2016

Well, no word from the shop yet. No news is good news?

clark grizwald · April 9, 2016

So no one here could give me a guess or any insight as to what they think?

00Silverado4x4 · April 11, 2016

Just as a guess I'd say you may have water or crud in the bottom of your tank that is being pulled from the bottom. You may also have a fuel pressure regulator problem as well.

davester · April 12, 2016

check fuel pressure at the rail, see if you can rig it so you can see the gauge while driving. It seems like your fuel pump can't keep the right pressure when you are at high speed. could also be the fuel-pressure regulator at the fuel rail.