Hey guys just looking for a little guidance here. This has happened to me twice in the last 3 days and I am starting to get a little concerned. As I am driving down the road at a steady spped (55) the rpm's start to drop off and I start to slow down, this lasts for about 5-10 seconds then it seems to clear itself up and then continues to run great. Like I said it happened the other day as I was going to work. I put two bottles of the chevron fuel additive and I thought that cured it but it did it again today. It seems like it is not getting fuel or something, sputters a few times, then runs like nothing was ever wrong. Is this enough info to investigate or do I have to wait till it dies????

 

Possibly could be water in the gas. I'm not sure if the Chevron will disperse the water like some of the gas anti-freeze products that are available. Check the label on the bottle to see if it says it is to be used to remove or disperse water.

If I remember right, a bad fuel pump will act worse when you have less fuel in the tank, because it has to work harder to push the fuel to the engine. If you can pull the codes with the ignition switch or go somewhere to have the codes read, that would be a good place to start to find or rule out other components.

 

Both times it did this I had at least a half tank of gas. I can't pull the codes but I will go somewhere that can and see if there is any code to pull. If the truck throws a code is there any light or anything on the dash that says it threw a code??

 

When it sputtered, were you still running on the same tank of gas, or did you stop and get more gas in between when this happened?

A code may be set, but it may not always cause the check engine light to come on. If your check engine light (CEL) stays on after the truck has started, then you definately have a code. I've heard that Autozone and other auto parts stores will check codes for free. On many vehicles, if you turn the key on and off three times in a row, it will cause the computer to go through a self check and display the codes, either by flashing the check engine light or by displaying the code in the digital odometer. I'm not sure how it will work on your year of truck.

If you have no codes and are sure the problem isn't water in the gas, then I would do some a search on fuel pumps. There is plenty of good discussion on this site. From what you described, it does sound like a fuel or fuel delivery problem.

Some other things to think about. Does it idle smoothly? How is the acceleration, does it stumble when you stomp on it? If it seems to have other symptoms, post back and that might help others come up with a diagnosis.

 

I was not running on the same tank of gas I did add gas when I added the fuel additive. It idles smoothly and it does not hesitate when I jump on it. There is really no other symptoms to add. It is a 5.9 with 118k on it. I have really had no problems what so ever with the engine. Thanks for the help.

 

Well on my way home tonight from work the check engine light came on. I will check with auto zone tomorrow to see what the code is.

 

Well I just pulled the codes by doing the key on/off 3 times and these are the codes that I got. A 33 (AC clutch relay circuit) and a 42 (Auto shutdown
relay circuit) any ideas what to do with these. I am not the most mechanically inclined individual either.