2002 Duramax I need Some Suggestions

[Todd NE WY]

Guys,

My 02 Duramax has been having problems when it gets below 0 out. I treat the fuel with Power Service, initially I thought it was the transmission because it felt like it didn't want to smoothly shift thru the gears. Usually it got better as the truck warmed up and completely disappeared when the outside temp went up. I had the transmission worked on they changed a temp sensor. I didn't have a chance to test it until this Monday when the temps dropped again. Back to the same sluggish running. My son took it and had the codes read and they said it had a low fuel rail pressure code and to start with changing the fuel filter. On monday I filled it up at noon and put Power Service in it when I got home, let it run for awhile to circulate, I also put some Diesel 911 in it thinking if may be the fuel filter was alittle gelled or iced it might clear it. It started Monday night dieing for no reason, yesterday morning it started right up and idled fine to warm up but as soon as I tried to drive it died. I changed the fuel filter out, it was -20 while I did it. It runs slightly smoother but still dies randomly, sometimes it runs for several minutes and sometimes just a few seconds. I was able to get it up to about 40 mph last night but that was as fast I as wanted on the dirt road and it was still dieing to often to go out on the main highway.

Any suggestions would be greatly appreciated.

Thanks in advance.

Todd

 

[Diamondpilot]

First off you should have put the additives in the fuel when you were fueling it, not after. I would add more diesel 911 and get the whole truck warmed up in a garage with a salamander on it. Get the entire thing upto 50/60 deg for a few hours to.

On later model Dmax they have issues with the air filters getting light powdery snow in the air filter element. Pull yours and check it for possible snow/ice before heating it up in a garage. If you melt it it will just re-freeze and cause bigger issues.

I had a D-max a few years back but switched to Ford. I can not remember if it has a fuel drain under the cab or is it just the one on the bottom of the filter in the engine bay? My Fords both have a drain under the drivers door for water and have a light on the dash if it gets water at that drain. Check your manual.

Chris

 

[Todd NE WY]

Chris,

Thanks for the info. I usually do put the additives in with fueling but didnt have it with me and I do have it in a garage now. I will check the air filter I hadn't thought about the fact if it cant draw enough air it wont run and we have been having a lot of the powdery snow lately.

Thanks,

Todd

 

[Diamondpilot]

Talked to my neighbor just now. He has a 07 Dmax and I had a 05 Dmax and his brother has a 06 so we know all the little problems with them pretty well. He says if its not gelled fuel or a clogged air filter it has to be the fuel. We are not sure but some diesels have 2 pumps. A electric one in the tank and a high pressure one on the engine itself. My guess is if you are seeing low rail pressure you have a high pressure pump issue.

Chris

 

[Todd NE WY]

Thanks Cris,

My son is picking up an air filter, we will put it on tonight and see what happens. I could see either the filter or fuel pump being the culprit. It seems the air filter the most likely due to the fact that the original problem never happened until the outside temp got below 0. But the fuel pump could be weak and just acting up when its cold.

Thanks again for your help.

Todd

 

[Diamondpilot]

Thanks Cris,

My son is picking up an air filter, we will put it on tonight and see what happens. I could see either the filter or fuel pump being the culprit. It seems the air filter the most likely due to the fact that the original problem never happened until the outside temp got below 0. But the fuel pump could be weak and just acting up when its cold.

Thanks again for your help.

Todd

Did you find anything in it? Also check the mass air flow sensor in the intake tube between the filter and intake manifold.

Chris

 

[Todd NE WY]

Chris,

Unfortunatly I am stuck at work till 6 tonight. I will let you know what I find. You have been extremely helpful and I appreciate the help.

Todd

 

[PoorMansCat]

The 03 model I drove (work truck) did NOT have an electric transfer pump... (in tank, frame mounted, or engine mounted)
My 03 LB7 engine had a 3 stage injection pump, the 1st stage was responsible for drawing the fuel from the tank, thru the filter and up thru it and push it into the second stage...
We lost countless injection pumps and injectors on these engines... One problem we had was the fuel filter base/priming pump assembly failing and casuing the system to lose prime.
Your local Mac tools dealer can sell you a pressure test kit for checking you fuel pressures at various points.

 

[crbr]

Guys,

My 02 Duramax has been having problems when it gets below 0 out. I treat the fuel with Power Service, initially I thought it was the transmission because it felt like it didn't want to smoothly shift thru the gears. Usually it got better as the truck warmed up and completely disappeared when the outside temp went up. I had the transmission worked on they changed a temp sensor. I didn't have a chance to test it until this Monday when the temps dropped again. Back to the same sluggish running. My son took it and had the codes read and they said it had a low fuel rail pressure code and to start with changing the fuel filter. On monday I filled it up at noon and put Power Service in it when I got home, let it run for awhile to circulate, I also put some Diesel 911 in it thinking if may be the fuel filter was alittle gelled or iced it might clear it. It started Monday night dieing for no reason, yesterday morning it started right up and idled fine to warm up but as soon as I tried to drive it died. I changed the fuel filter out, it was -20 while I did it. It runs slightly smoother but still dies randomly, sometimes it runs for several minutes and sometimes just a few seconds. I was able to get it up to about 40 mph last night but that was as fast I as wanted on the dirt road and it was still dieing to often to go out on the main highway.

Any suggestions would be greatly appreciated.

Thanks in advance.

Todd

Possibly the injectors / and fuel system combined. A known and inherent problem with the LB7 engine.


Have a look on the Diesel page. A lot of knowledgable people there....

TheDieselPage.com Forums - Powered by vBulletin

Also browse www.kennedydiesel.com for info.


.

.

 

[Bswope]

Possibly the injectors / and fuel system combined. A known and inherent problem with the LB7 engine.


Have a look on the Diesel page. A lot of knowledgable people there....

TheDieselPage.com Forums - Powered by vBulletin

Also browse www.kennedydiesel.com for info.


.

.

Yep my buddy just had his injectors replaced in his early 04 (LB7)....

You can also look on Duramax Diesels Forum - Powered by vBulletin for some help, BUT I must warn you once you enter these sites you will get bitten by the diesel bug and begin to uncontrollably spend money on performance parts! Trust me on this..... Ive got about 5-6K into my 06 Cummins engine!:thumbsup:

 

[lostcause]

i own a 2001 lb7, and as has been mentioned, there is no electric fuel pump, just the injector pump for supplying fuel. i have two tanks, and the fuel system only draws fuel from teh front tank, so there is an electric lift pump in the rear tank that pumps fuel to the front tank to keep them level.

anyways, on to the non-running issue. it's hard to say, but if you've looked at the obvious things, injectors are number one on the list of issues with that vintage duramax. it's obviously not something you want to guess on, as their cost is staggering, so make sure the diagnosis is valid before heading that route.

i did the injectors in mine a year and a half ago, much to my disgust, but it had to be done. since then i had another issue with the vehicle running poorly, and occasionally losing prime if not used for several days in a row. that ended up being a fuel leak. the fuel lines are one piece and incredibly long (and incredibly expensive) on that truck. if possible, check them for damp spots that woudl indicate a leak. drawing air into the system will wreak havoc on the way it runs - even if the leak is in the return line. i spliced about two feet of rubber line and a new nipple fitting where the return line enters the fuel cooler. been working ok since then.

 

[Diamondpilot]

I though injectors also but when my 05 had injector problems it ran rough and smoked on start up. I hope its not injectors but could be. The Dmax is know to eat them. I had to replace mine in the first year of ownership.

Chris

 

[Ryan03]

Sounds like a fuel gelling/quality issue to me.

Facts
Low rail pressure code stored

Poor drivability only experienced when temp is zero or below

Changing fuel filter yielded slight improvement in idle quality

Here is my advice, 1st, remove all the current fuel from the tank, 2nd go to a different place than you normaly go, and buy 10 or so gallons of fresh fuel {preferably from a busy place where the fuel does not sit in underground storage tanks forever, as ULSD absorbs moisture quickly}, 3rd, remove your new fuel filter and cut it open and pull the paper out to see if any crud is stuck in it, if so clean system accordingly, if not, pour in the new fuel. Install a new filter and give it another try.

Based opon your symtoms that are only brought on by cold ambient air temps, I realy don't feel it is an injector issue.

 

[Todd NE WY]

First off thanks for all the suggestions and help.

Fortunately or unfortunately it is running fine starting last night after a new air filter. The major if in the equation is the abient temp was 5 when I started it last night and it typically only acted up at less than 0.

It has been suggested it may be the Mass Air Flow sensor, anyone have any experience with that?

Also this one did get new injectors in about the 2nd or 3rd year after it was new.

 

[Diamondpilot]

Glad you got it going. Did it start fine after you warmed it up and put in the new air filter? Still seems like you may have had some moisture in either your filter or fuel.

Chris

 

[PoorMansCat]

one other thing... our 03 LB7 engines eventually got an extended warranty on the injectors and labor.... it was raised to 200K by GM/Isuzu on many/if not all of the LB7 engines. GM really stepped up on that one...

 

[crbr]

one other thing... our 03 LB7 engines eventually got an extended warranty on the injectors and labor.... it was raised to 200K by GM/Isuzu on many/if not all of the LB7 engines. GM really stepped up on that one...

200,000 or 7 years. It's over.

 

[PoorMansCat]

200,000 or 7 years. It's over.

aahhh... i c... I knew it was 200K, didnt know about the time deadline..