LB7: Problem Shifting at 3000RPM

[03DuraMax4x4]

Hi,

I'm new to Diesels. I have a 2003 Silverado 2500HD DuraMax. Everything in it is stock. It has 153K miles. I recently had 4 of the fuel injectors replaced. The others tested out good. The air filter is almost new (about 3K miles - Fram ToughGuard).



Earlier today I was parked up a steep hill and had less than 1/4 tank of gas. To make a long story short, the truck died on my right after cranking and it took some work to get it started, but after adding fuel it finally cranked.



My question is this: After getting it started back up I drove the truck around and decided to test the acceleration. I noticed that when I'd floor it (at about 20mph) the truck would accelerate until it got to about 2900-3000 RPM and then act like it was choking out: It would sit at that RPM range and start loosing power. As soon as I let off the gas slightly and the RPMs dropped to about 2500 it shifted up and the turbo kicked in. This is the first time I have noticed it do this. I normally don't floor it (gradually accelerate and let teh turbo kick in), but this time I wanted to push it a little more and see what it had. My thinking is that it should have shifted up regardless of the RPMs. I had about 1/2 a tank of fuel when I was testing the acceleration.



Any comments / suggestions would be much appreciated.

 

[MeanDmax]

Change your fuel filter first, easiest thing to do.:thumb:

 

[03DuraMax4x4]

Thanks,

I'll do that. The guy that installed the new fuel injectors supposedly installed a new fuel filter, but it won't hurt to replace it to be on the safe side (I'm not very happy with the overall experience with him).

Will post later on with the results.

 

[sr23det]

hope the fuel filter helps....

 

[TheBac]

You could also be lower on fuel than 1/4 tank. Sometimes the gauge lies. Get some fuel in it, too.

 

[JoshH]

Sounds like you're dropping rail pressure.

 

[03DuraMax4x4]

Here is an update on the truck:

I went and bought a WIX fuel filter and installed it. I immediately noticed that the fuel that came from the old filter had a lot of dirt in it (see picture below). This is filter has been installed for only about 3 weeks now.

I primed the filter as directed in the owner's manual and the truck started right up. After about 45 seconds of idling the all of the sudden died out (RPMs started fluctuating right before it died). I was outside of the truck looking at the engine when this happened and my dad, who was in the truck didn't think to give it gas to try and keep it running. We tried priming the fuel filter (it kept loosing it's prime after each ingition attempt) several times and were unable to start the truck. We ended up running the batteries down and having to buy new ones because the failed the battery test at Advance Auto Parts.

Afte installing the new batteries I reprimed the fuel filter and after a couple of tries it fired up. This time I was at the wheel and smoothly pressed on the throttle. Everything sounded good, smooth, and strong all the way up to 3000 RPM. I slowly let off the throttle and it came to a good constant idle. I decided to take it for a drive. The truck died on me again only after about 400yds going about 10-15mph. I reprimed the filter and started the truck and continued to try and drive it. It died about 1/4 mile down the road. This was repeated about 10 times (the distance getting further with each time - this was Labor Day evening and I still had a 100mile drive to get home that night - I had to do everything possible to get it going). I did notice that the truck never died when I was accelerating; it always down on the deceleration (or lowering of RPMs after a shift point). By a miracle it started and kept going all the way home, but I had NO power (it felt like I was driving my parents' Camry).

I took it to the shop this morning and they are still looking at it.

Right now I think that it may be just a clogged line. The intersates in Clinton are extremely bumpy and I think all of the bumps loosened debris that had probably settled over the life time of the truck and clogged the fuel lines.

It is the only explanation I can think of for why the filter would be almost empty after it died every time, and why it only died on decelerations. I had the 4 fuel injectors on the passanger side replaced about 3 weeks ago and the mechanic also cleaned the fuel rails so I doubt (REALLY HOPE) that is not the problem.

 

[03DuraMax4x4]

*** The Verdict ***

And the verdict is:


2 collapsed fuel lines. They said that both lines had been completely collapsed. They are ordering the new ones and will install them.

 

[03DuraMax4x4]

Finally got my truck back and everything is running great! They figured out that the guy that replaced the fuel filter when he changed out the fuel injectors didn't remove the plug on top of the filter and that is what caused all of these problems.

 

[x MadMAX DIESEL]

Plug on top for the filter?

 

[dirty_725]

well im having the same problems with my truck.. didn't notice it untill i pulled out in front of some traffic and had to get on it a little bit. it was like it started to slip and the motor just stayed reved up, then i let off and it hooked back up and started accelerating again?

 

[03DuraMax4x4]

Plug on top for the filter?

They said there was some type of plug on top of the filter. I never saw one when replacing it, but they gave me back the plug that started all of the problems.

well im having the same problems with my truck.. didn't notice it untill i pulled out in front of some traffic and had to get on it a little bit. it was like it started to slip and the motor just stayed reved up, then i let off and it hooked back up and started accelerating again?

That is exactly what mine was doing when the problem first started. Keep me posted. Hope you can get yours fixed without all of the headaches I went through.

 

[JoshH]

They said there was some type of plug on top of the filter. I never saw one when replacing it, but they gave me back the plug that started all of the problems.

Can you post a picture?

 

[feltersnatch]

Are you talking about the bleed screw, or maybe a bad primer? The only thing on my filters are o rings.


X2 on pics or description of the "plug"!

 

[dirty_725]

ok my truck is def. getting worse. not good, lol now i don't have to get on it... i been driving the truck easy for a month now, and i can be crusing down the road 50-60 mph and ease on the gas to speed up and when i hit 2000 rpms or close it will start to slip untill i let off the throttle and it starts pulling again. i got a vibration now for a lil while, almost feels like a tire is outta balance but just had it done so i kno thats not it.

what ya guys think???

 

[dirty_725]

anybody got any thoughts about my problem?

 

[DAVe3283]

Can you get a video? That might help a lot.

That, or you need to find someone with EFILive and have them log your truck. That is the most reliable way to diagnose it.

 

[03DuraMax4x4]

I know we are past my truck issue and these are a bit late, but here is the "PLUG" that they said caused all of the problems.

 

[03DuraMax4x4]

anybody got any thoughts about my problem?

Have you had anybody else look at it?

 

[JoshH]

I know we are past my truck issue and these are a bit late, but here is the "PLUG" that they said caused all of the problems.

That is the seal in the center of the filter. I've had it stay on the filter head once when I changed my fuel filter. I couldn't even get the new filter started. I would be surprised if the place who changed your filter got it back on with that still stuck on there. If they did, they had no business working on your truck in the first place. I'm going to go out on a limb and say the place you took it back to took the filter off and the one from the filter that they took off is what they found.