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2001 - 2500HD - 6.0 Liter - Fuel Gauge is Wacky and Long Starting issues

10K views 3 replies 4 participants last post by  BiggWebb 
#1 ·
I have a 2001 6.0 Liter 2500HD, that is now giving me some problems. History of the vehicle it has about 180,000 miles and was bought from a wholesaler about 2 and half years ago with about 150,000. Not sure of the history prior to that point, but immediately after purchase I changed every fluid to have a fresh start and have maintained a religious PM schedule. The fuel filter was changed about a week prior to the problem #2 showing up.

1. For about 6 to 9 months I have noticed the fuel gauge reading full one minute and empty the next, this happens more following a fill up. This will continue to happen until the fuel level reaches about 1/4 to 1/3 full and it will stop. Other than being annoying, it does not seem to be a problem, because I reset my trip-o-meter and use that to determine my next fill up. Just in-case the fuel gauge is not accurate. (I think that is the sending unit going out.)

2. The next problem started about a month and a half ago, and could possibly be associated with problem #1, and it is that I am having an increasing starting period. What I mean is that a month and a half ago when this started I noticed that my truck was not starting, when I held the key for the normal starting time period, and I thought that maybe I was not holding the key long enough. By the next week this starting period had increased to 1 to 2 seconds, and with each passing week it appears that another second or two is added to the starting time. If I attempt to start the truck and left off the key and then retry the truck starts normal, but I have noticed this week that does not even appear to be working and the second attempt to start the truck is taking a second or 2. If I have been driving the truck around, and stop for only a few minutes, and return to start the truck the engine will start normally. (I have been thinking that it is the fuel pressure regulator, but I changed that last night and still having the same problems. Have also recently changed the spark plugs, but still the same distributor.)

Any thoughts....

Thanks,
 
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#2 · (Edited)
More than likely a fuel module, which is the pump and sender together. Whats probably happening is after the vehicle is shut off the fuel pressure is bleeding down so it takes longer to start. Next time, cycle the key a couple times before cranking, then crank it over. If it starts up right away then it is most likely losing pressure.

The sender gets corroded over time and certain spots have excessive resistance or are open so the gauge goes to E when it encounters one of those areas.

Of course, that is something fairly easy to diagnose at a shop, but thats what I would put money on.

Oh, and the 01 doesnt have a distributor anymore, it has a coil on ignition system.

edit - I just re-read your post and missed the regulator part. Some of the fuel modules have the regulator built in to them, rather then up at the fuel rail.

So that changes things a bit. Does it run rough for a few seconds after it starts? It may be an injector leaking fuel when shut off which can cause low pressure at start up, then the fuel in the cylinder could cause it to run bad until it clears out. It could also still be a fuel pump. If the "vanes" of the pump are worn and not sealing the pressure in, or if the flex hose is cracked from the pump up to the top of the module, it would allow that pressure to bleed down.

Anyway, there is a fuel shuot off tool they use to isolate the source of the leak down that generally makes it a snap to figure out. Of course it could be something other then fuel related, but that is the most common cause for extended cranking. The first thign to do is check fuel pressure with a gauge. If it isnt dropping, then it is something else, like crank signal issues or something ignition related.
 
#4 ·
I have a 2001 gmc 2500hd as well it has 98000 miles on it and i have exact same problems you do, if i sit in the truck while its running the gauge goes back in forth, but gets going good when i drive. also i changed my fuel pressure regulator and it helped a tad bit on my startup problem, i honestly dont know what to do with it now i have a exhaust manifold leak too. any ideas may be a fuel pump problem?

And did you find a solution that may help me with my problem?
 
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