My 2004 LLY has been in the shop for two weeks going through diagnostics.


The truck will not go past two thousand RPMs after approximately 5 minutes of driving. If the accelerator is pressed quickly it will surge until it reaches 2000 RPM. If you slowly press the accelerator it will smoothly reach 2000 RPM then stabilizes, but will not continue past 2000 RPM.<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />


The initial fix performed by the dealer was replacement of the fuel flow sensor switch, but this was not successful. The dealer and the GM tech reps are not sure what the problems is, but they have ordered a new set of injectors.


Idles great, no smoke.


Any ideas?

http://www.dieselplace.com/forum/smileys/smiley4.gifYou might post this on the "Ask the Tech's" forum as well. JJ

Do you have an edge Juice in the truck?

Quite a few people have seen the same thing runing the edge in level 5. There hasn't really been any real answers yet.

No, everything is stock.

Just curious what injector replacement will solve? Keep us posted!

I'd flow test the fuel system. I take it you've checked the fuel filter
for restriction. Perhaps there is a kink on a line somewhere.

5 new injectors didn't fix the problem.


Dealer will begin replacing fuel pumps (understand there is more than one)...will keep advised.

Lott4240 where are you in VA?

Northern Va...Springfield area

Hello, I was wondering if you have more info on this? Mine
started this a few days ago. It will run perfectly normal at
first, then slowly it will keep lowering the max rpm it will run at
until 2000rpm is the max. This takes my truck about 20 minutes of
driving to get it to that point. Its like the power just shuts
off. It will run hard until that point and then nothing.
I'm bringing it in tomorrow for the updated AC/PS bracket, so I'm going
to have them look at this problem also.



Thanks,



Craig

With all this computer stuff, is it possible that something in the cruise control circuit or the 'high idle' circuit, could be 'limiting' the rpms?


Also, I thought the Allison had some kind of "Limp Home" mode, if there is a problem with it. Just some ideas from a layperson.

Got the truck back last week after all injectors were replaced. Dealer was happy they had finally fix the truck.


On the way home it began again...truck is now back at the shop.


Will keep you informed.

Tranny slipage or faulty signal??

I would take a look at the transmission, and its possibly engaging into limp mode. If you cannot activate the Tow/Haul button, that is a sign there if a problem there.

Arn't these trucks "drive by wire" stuff? If the pedal is on the floor, what's the signal look like? What does the TECH II say while driving? Is there a fuel restriction at the filter or in the lines? Maybe it's just that loose connection with the switch that everyone has been talking about? http://www.dieselplace.com/forum/smileys/smiley5.gif





Burner----------------&gt; http://www.dieselplace.com/forum/smileys/smiley4.gif

Dealer just called...will replace the fuel pump.


Hopefully this will work.

Why not get some trained techs at the dealer?http://www.dieselplace.com/forum/smileys/smiley19.gif





Sounds like all you need are parts changers.





Guess logical troubleshooting would take too much time to correct the problem quickly and professionally the first time.





Might have to tell them righty tighty and lefty loosey. They sound like they stink as a technician.Edited by: jefro

I think they are waisting their time on the fuel system end of it. I would be looking at electrical/electronic components. I seriously doubt it is a fuel system issue as many others have had the same problem when running the Juice and it is too precise to be fuel related in my opinion. What are the chances that a restriced fuel flow would limit it to exactly 2000 rpm in every instance? No very likely.

My 2004 LLY has been in the shop for two weeks going through diagnostics.


The truck will not go past two thousand RPMs after approximately 5 minutes of driving. If the accelerator is pressed quickly it will surge until it reaches 2000 RPM. If you slowly press the accelerator it will smoothly reach 2000 RPM then stabilizes, but will not continue past 2000 RPM.<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><O:P></O:P>


The initial fix performed by the dealer was replacement of the fuel flow sensor switch, but this was not successful. The dealer and the GM tech reps are not sure what the problems is, but they have ordered a new set of injectors.<O:P></O:P>


Idles great, no smoke.<O:P></O:P>


Any ideas?<O:P></O:P>











Does it shift into all gears? Or does it stay in say, first or second?

Transmission appears to work fine. If you have the throttle pressed way down, with still just a max 2000RPM ,going down hill and let off...the engine will rev up over 2000RPM. I'm guessing the transmission is kicking in to slow down the truck.


Does this make sense?

Is the rev limiter, hardware or software?

Well it gets better, got a call today to say the fuel pump hasn't come in and your truck was damaged by another customers vehicle.


So I have a brand new truck that doesn't work and is damaged. Also, the 25K dollar trailer it is suppose to pull on vacation is sitting still.

rase some hell

Holy crap, Batman!


I think I'd be getting something from them for free for a LOoooong, LOoooong, time. Free oil changes, free something. I agree with Max Power, no way it is fuel system related. What about the possibility that it is a faulty sensor, ground, or ECM? Just thoughts.


Dennis

I have a tracking number from GM now and told them I want the truck bought back if this fix doesn't work...not sure they will agree.


The fuel pump is on backorder...the dealer said diesels have been having problems with the fuel pumps.

not that this is the same but I had a customer bring his truck in c(4500) with the same concern would not rev drive or neutral. this guy had the pto switch turned on. I dont know if there is a similar system wired into our trucks that maby shorted or what not. I will check tommorow. also easyu way to check with tech 2 is look at app position make sure it reads 100% when you mat it. fuel pump wont fix nothing. unless truck cannot build rail pressure that can be easily checked with the scanner. John

Might be a sticky EGR. Had a similar problem. Dealer replaced the EGR. I then disconnected the EGR and have not had the problem return. However, still have too much smoke for a stock engine.

Fuel pump fixed mine, same symptom, 3k miles. http://www.dieselplace.com/forum/smileys/smiley7.gif STTTRIIIIIIIKE 1!

please post what you find out about your truck , my2004 lly started the same thing today. 2000rpm max after warm up? dealer has no idea why.

Well I think ronadycks is right it is going into limp mode. However I don't know why either. Keep us posted

Let me tell you why I like mechanics that don’t do their job
properly. The dealer and the manufacturer think they have you
by the short arm by telling you ‘ we can’t find anything wrong” of
the infamous “ can not duplicate problem”

To make a long story short I had a vehicle ( not GM) that had a
recurring problem, so i called the Mfg., and the sixteen year old
on the “customer service“ line somewhere in sri lanka*, was
sympathetic and quite useless. I just said thank you and I only
have to take it in for the same problem three times and it’s
Lemon.

So I picked up the vehicle, it still had the problem so I drove it
around the block and brought it back in for service - that makes
two times, - picked it up again with the same answers, drove it
around the block and took it back in again ( each time with a
new service number) . Now that makes three and qualifies it as
a lemon

I am now waiting for my new vehicle ordered fresh.

A week later the fuel pump came in...truck still doesn't work. Technican says he has no clue...has run out of ideas. GM says they have top management on the problem.


I just want a truck that works.


35 days in the shop and counting!

No offense to the techs that are here and actually know what there
doing but sad to say most of the techs that I ever had to deal with at
the dealer are next to worthless, all they know how to do is swap parts
so no suprise to me that they've swapped all the parts the book told
them to do and now they have no further clue as what to do.
Sorry, I know this rant doesn't help you any but in my mind GM should
have already flown an expert to that dealer to fix your truck and then
make sure that knowledge gets dispersed to all the dealers in the
country. This ultimatly reflects bad on GM and people go elsewhere next
time.

Replacing the fuel pressure relief valve today to see if this will fix the problem.


40 days in the shop and counting.

They have given you a loaner vehicle at no cost havent they? It's in your buyers contract.

Its hard to be a good mechanic....problem solving is a hard skill to develop. Maybe I should have pursued being a mechanic instead of a doctor. I know from experience that the automotive industry is lacking in this area. Luckily...we have some of the good ones surfing this board...thank you guys!!

My fuel filter pluged up and did this also. After replacing the filter I had to cycle start it aprox. 20 times to clear code.

My 2004 LLY has been in the shop for two weeks going through diagnostics.


The truck will not go past two thousand RPMs after approximately 5 minutes of driving. If the accelerator is pressed quickly it will surge until it reaches 2000 RPM. If you slowly press the accelerator it will smoothly reach 2000 RPM then stabilizes, but will not continue past 2000 RPM.<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><O:P></O:P>


The initial fix performed by the dealer was replacement of the fuel flow sensor switch, but this was not successful. The dealer and the GM tech reps are not sure what the problems is, but they have ordered a new set of injectors.<O:P></O:P>


Idles great, no smoke.<O:P></O:P>


Any ideas?<O:P></O:P>











BEST advise I could give at this point it to negotiate with GM for a repurchase. Assuming it is under warranty, they should not give you much fight. If they do not work with you, I would seek legal counsel, specializing in Lemon Law.


Even if they got it fixed at this point, I would not trust the truck to give you long term service. They have already mix and matched parts, while doing "exploratory surgery" on your 40+ thousand dollar truck...

The part didn't fix the truck. Starting the buyback process. Truck only has 9,000 miles.

The part didn't fix the truck. Starting the buyback process. Truck only has 9,000 miles.


Now you're talking. You should take a hit on the mileage based on the mileage you had when first making notice of the problem.


If that was 9000 miles, then you will probably take a hit of about $3,200.. If you use an attorney, you should get your interest paid on the loan, but if you do the repurchase, they might try to screw you out of that. I know. I just went through it. They repaid all upgrades, such as my bedliner, shocks, etc..


Good luck, and don't let them screw you .


One thought... After going through it, I would still consider a Lawyer, since most take the case on contingency, and then you don't have to deal with GM. The costs are borne by GM. And the lawyer will fight for ALL your recovery options. Plus, a lawyer will get the job done faster I think.


Let us know...

Lott4240, I feel for ya! &lt;OUCH&gt;


Good luck!


Cheers, Jeff

Dealership called yesterday and said the truck was fixed. It appears it was the fuel pressure...exactly what they did I don't know as of yet. They drove it for an hour and said it worked fine. So I will take the truck back and see how it goes.


Will keep you informed.

Dealership called yesterday and said the truck was fixed. It appears it was the fuel pressure...exactly what they did I don't know as of yet. They drove it for an hour and said it worked fine. So I will take the truck back and see how it goes.


Will keep you informed.





LOTT:


I would NOT take this truck back. I would insist on a new vehicle. You paid way too much money for this truck, to just "Take It Back", with nothing for your trouble.


Depending on your state, I believe you have a legitimate repurchase, even if they "FIXED" it. Why take the chance, with a truck that has let you down? GET A NEW ONE&gt;&gt;&gt;&gt;&gt;&gt;


PLUS, you get to drive this one until the repurchase is completed.