I will be going to the dealer for help, but I wanted to get input from you guys first. My LB7 seems to be sick. Last week, it stalled while I was cruising on the highway. Engine was warmed up (had been driving 20mins), outside temp was 20C. I was just cruising along at 65mph and the engine just stalled. All electronics were fine. I was able to shift into Neutral and restart while drifting. I took out the fuel filter (was only 1000km old) and replaced it this past Sunday morning. All day Sunday I used the truck without a problem (45-50mph tops), and yesterday's drive in to work was good (about 40mi each way 60-70mph). I thought I had nipped the problem in the bud, but this morning I stalled on the highway again (cruising at 60mph). I have inspected everything for leaks and I see nothing leaking 'out'. How easy should it be to pump the prime button once the truck has been run? I can pump it til it's rock hard (<10 pumps) but after running the truck it's not rock hard anymore, and I can pump it 5-7 times again.

So far it has only stalled at highway speed (60-70mph), and it restarts right away.

Still having a problem?......:eek:

Sounds like you have an air leak. You wont see any leaks either because its on a vacume to your injection pump. Meaning the CP3 pulls the fuel via vacume to the pump instead of a pump in the tank like a gasser, so if you have a leak its air getting sucked in instead of fuel leaking out.

I would guess it happens on the highway because your rail pressure is higher and it is asking for more fuel, sucking in more air until you stall. That primer should be staying hard as a rock. Get it good and primed and cllose the screw and keep trying to pump the prime, see if it forces fuel out anywhere.

I know those plastic bleeder screws suck. They can cause your issue. Putting on a fuel filter improperly ( ive done it) will cause a leak. Other than that you could havea cracked filter housing or a loose line somewhere.

Yeah, still having problems. I check around where you mentioned in my earlier thread for leaks and didn't find any, and after replacing the fuel filter I still had issues so decided to post in here instead of continuing my other thread since it was in the Electric forum ;)

I'll give the primer a shot tonight to see if it pushes any fuel out, but it is definitely not rock hard after driving. Like I mentioned, I can pump 5-7 times after a short drive to get it back rock hard.

Yeah, still having problems. I check around where you mentioned in my earlier thread for leaks and didn't find any, and after replacing the fuel filter I still had issues so decided to post in here instead of continuing my other thread since it was in the Electric forum ;)

I'll give the primer a shot tonight to see if it pushes any fuel out, but it is definitely not rock hard after driving. Like I mentioned, I can pump 5-7 times after a short drive to get it back rock hard.

You definitely have an air leak somewhere. I would take that bleeder screw out and inspect it for cracks. Replacing it with a better metal one wouldnt hurt. I think one of the vendors on here sells them. If you wanted fast fix, call your dealer and see if they have one on the shelf, i couldnt see them costing that much.

Also look through your fenderwell and make sure your fuel filter gaskets are in place.

Well... checked the bleeder screw, and it looked fine. I ordered a nice shiny metal one from here anyway. Plastic ftl. Also yanked the fender well and inspected the filter/O-rings, and they look fine as well. Primed her up until I couldn't press anymore, and then pressed it more and no leaks. Rock hard primer. But still stalled once this morning driving into work, and twice on the way home. After turning it off, I could press the primer at least 8 times before it was rock hard again (is that normal!?) I booked an appt. with the dealership for monday... I'll update when I find out wtf is borked :s

.... After turning it off, I could press the primer at least 8 times before it was rock hard again (is that normal!?) Yes, in my experience.

Had some random stalling and random no starts. Usually at slow speeds or while idling in park, never at highway speeds. Ended up being the reluctor ring on crankshaft was loose and moving around and crank sensor was llosing signal. Just got it back from dealer and it runs great now.

Mine did the same thing, except it got better. No schmo, it was dying after every start for about a week. I took off the outlet line and pumped fuel. Then it got all better. Must have been a piece of schnizzle stuck in the check valve allowing it to draw back from the left over vacuum.

Naturally, I ordered a lift pump initially. That will at least make priming an easy task on filter changes!

jb

Mine started doing the same thing. It kept getting worse (more pumps to prime) until I replaced the o ring at the base of the primer pump. I haven't had any problems since.

Well, it's at the stealership now.. hopefully I don't get soaked :s I told em I don't want it back until it's fixed lol

*sigh*... well, the stealership has had my baby for 3 days now... Tech says he's been driving it to/from work with a handheld connected, and the balance rates, fuel rail pressure all look spot on, and no stalls... FFS. I was stalling every day :( Told em keep it for one more day, and do a 'long' drive on the highway. All else fails I'mma put a match to it. But even if it does stall for them, will the handheld find anything? It wasn't throwing any codes when it stalled.

I just read this thread, and I had a similar problem. I'm not going to tell you or anyone else that it's not a fuel/air leak problem. I went through all the try this and try that stuff, as you are doing. I went to my local dealer, I know the tech there, and asked for a minute of his time to take a look. He plugged in his hand held, started my truck ran a few tests. He said that he couldn't believe what he found. He said that the foot feed (throttle pedal, or what ever you want to call it) is like a rheostat and it regulates the electric current to the motor that operates your throttle.(throttle by wire) Well it had a dead spot, and when it got to that spot (what ever your MPH might be) it would drop the signal to the throttle motor and shut the engine off. Well when I would tried to restart after stopping, or drifting as you said earlier, it would start right up. He had to order the new throttle/rheostat and I haven't had a problem ever since. Just my 2 cents worth. Take care and good luck.

What did it run you for the rheostat? If it's cheap enough it may be worthwhile to start throwing parts at this thing lol

Here ya go....my 2 cents.... I have heard that the crank sensor (as listed earlier) is a bit picky. Sometimes when the engine gets a weird signal it can't understand...it'll shut off. I'll take a look in GM see if I can find you a trouble shoot for this, but if there wasn't any codes, it may be difficult to figure out.....

*grrrrr* ... So I go to the stealership, they say after 4 days driving it around, they can't reproduce the problem. Tech2 reports everything is dandy. So I drive it home... and it stalls on the highway. Wtf. I'm just in a lousy assed mood now. Feel like driving it 'through' the dealership.

More details:
While driving at 100km/hr, suddenly I feel like a lack of power like it's going to stall out. Battery light comes on, rpm gauge starts fluctuating (bouncing 1k/3k/0...). Giving it gas doesn't help as it slowly dies (stalls out after about 5-10secs). Shift it to N, and crank her about 2-3secs and it starts back up. Shift into D and continue on my way home.

*fit to be tied*

*grrrrr* ... So I go to the stealership, they say after 4 days driving it around, they can't reproduce the problem. Tech2 reports everything is dandy. So I drive it home... and it stalls on the highway. Wtf. I'm just in a lousy assed mood now. Feel like driving it 'through' the dealership.

More details:
While driving at 100km/hr, suddenly I feel like a lack of power like it's going to stall out. Battery light comes on, rpm gauge starts fluctuating (bouncing 1k/3k/0...). Giving it gas doesn't help as it slowly dies (stalls out after about 5-10secs). Shift it to N, and crank her about 2-3secs and it starts back up. Shift into D and continue on my way home.

*fit to be tied*

Exactly what you said here (more details) are the same symptoms that I experienced. The rheostat was covered under warranty.

Can you get the tech to take a ride with you? Would have been nice if the tech was with you on your way home.

*grrrrr* ... So I go to the stealership, they say after 4 days driving it around, they can't reproduce the problem. Tech2 reports everything is dandy. So I drive it home... and it stalls on the highway. Wtf. I'm just in a lousy assed mood now. Feel like driving it 'through' the dealership.

More details:
While driving at 100km/hr, suddenly I feel like a lack of power like it's going to stall out. Battery light comes on, rpm gauge starts fluctuating (bouncing 1k/3k/0...). Giving it gas doesn't help as it slowly dies (stalls out after about 5-10secs). Shift it to N, and crank her about 2-3secs and it starts back up. Shift into D and continue on my way home.

*fit to be tied*

Sounds like the tech driving your truck is probably driving a differnt style than you and cannot reproduce the problem. Get him in the truck.

As for the Rheostat, have him hook up to the truck and fluxuate the throttle (Even with the engine off you get a reading), you can watch it on the screen to see if it has a flat spot.

Better yet, get on the highway and set the cruise, it no longer uses the TPS to run the engine (from what i see on efi, someone correct me if im wrong). It shouldnt stall, but thats just a guess.

Also, next time you feel a lack of power, get off the throttle right away and pull over and get it to a complete wheel stop with your foot of the throttle, see if it stays running......or, try to quickly set the cruise control see if it goes back to normal.

i know its a bunch of random shit, but maybe it will give you a few answers.....

Marc

Le *sigh*... well... been using the cruise the last couple of days and no stall... so I picked up the Accelerator pedal assembly (*can't get just the sensor in Canada... wtf)... then on the way home with the CC on, it stalled... I swear, someone up there hates me lol. I swapped out the accel pedal anyway when I got home... hopefully it'll fix the prob, but I'm not hopeful. I'm at the point now I'll just start throwing parts at it lol. Crank sensor next? lol

Thanks for all the help, it is appreciated.

I feel your pain. still no fix. http://www.dieselplace.com/forum/showthread.php?t=211745

the new ignition switch seemed good but... http://www.dieselplace.com/forum/showthread.php?t=249262




Joe

Replaced the Acc. pedal assembly, and had 1 good day of no stalling. Then this morning it stalled again on me... back to the drawing board. Wiggled the heck out of the key/switch while driving and couldn't make it stall. Any suggestions on next steps to debug? How hard is it to replace Crank Pos. Sensor or Cam pos sensor? Could a bad PCM cause something this intermittent (would it throw a code?)?

IIRC, people have had engine starting/stalling problems from the crank pos sensor coming loose.

But based on SGIJoe61's problem, sounds like it could be anything! He mentioned forcing the key up and to the right and it stalls. But i would think if you forced any key hard enough in a truck running correctly, it would also stall???

Is there anyway to monitor the crank and cam sensor?

Feel like lending me your EFILive? lol. I was honestly thinking about picking up one if it would actually help debug the problem... but 1k$ is a bit steep if not.

Any how-to's or diagrams about Cam Position Sensor or Crank Sensor? /me runs off to google...

"Forced" isn't really a good word for it. I would move the key around and it would stall the exact same way it had been, gauge jump , door locks etc.. This is only thing in the months I've had the problem to be able to duplica it. After the 5 month good run it stalled, but now is seems to stall on bumps. so it's got me beat. Oh and codes i've got is P0380 "Glow Plug/Heater Circuit "A" Malfunction"


DageonYar pm inbound

this has been my fix




joe

"Forced" isn't really a good word for it. I would move the key around and it would stall the exact same way it had been, gauge jump , door locks etc.. This is only thing in the months I've had the problem to be able to duplica it. After the 5 month good run it stalled, but now is seems to stall on bumps. so it's got me beat. Oh and codes i've got is P0380 "Glow Plug/Heater Circuit "A" Malfunction"


DageonYar pm inbound

this has been my fix


joe

I've seen better repair jobs than that photo! Don't give up

Feel like lending me your EFILive? lol. I was honestly thinking about picking up one if it would actually help debug the problem... but 1k$ is a bit steep if not.

Any how-to's or diagrams about Cam Position Sensor or Crank Sensor? /me runs off to google...

Come on down to FL and ill lend you a hand in diagnostics....

Do a search in the crank sensor theres a lot out there on it.

I've seen better repair jobs than that photo! Don't give up

No I'll not giving up! I wanted a second truck, the stall just forced it.

My '02 lugged on me three weeks ago at a stop sign, but it straightened up after a few seconds. Two weeks ago it stalled at a light, but fired right up. I changed the fuel filter last week, thinking that was the problem (it's been awhile on the old filter). But today, I went to leave the grocery store and it wouldn't start. Had it towed to a shop, and it started right up for them, but threw a code; the tech said it was the crank sensor. $400 to repair. I was hoping they'd be finished this p.m., but it looks like it will be Monday before I get my truck back. Anybody know where I can get a Duramax service manual?

Anybody know where I can get a Duramax service manual?

Helms has a nice 5 volume set. Covers more than you can use.

The latest DageonYar??

I haven't really had time to test anything out lately. Busy weekend building a new shed lol. But yesterday and today the truck behaved itself and didn't stall at all. I'm wonderin if the cooler weather may have something to do with it... or it's just a fluke.

I haven't really had time to test anything out lately. Busy weekend building a new shed lol. But yesterday and today the truck behaved itself and didn't stall at all. I'm wonderin if the cooler weather may have something to do with it... or it's just a fluke.

My truck has done the same as yours with the stalling last winter and spring. The entire summer it ran great with no stalling. Now the other mourning when it was colder 32F, it stalled on me. When mine starts to stall I just flip on the lift pump and it comes back to life so its deff a fuel problem, the same as yours because your prime is low. After reading this and thinking about my truck we probably both have a leak somewhere. When its colder out the leak would be larger then when its hot and explanded. I think I'm just going to buy a new filter housing.

How timely! Mine has done the quitting for over 10k mostly when in traffic and after several throttle changes so I blamed it on TPS. But two days ago it started moved a couple of feet and just quit have bee through the filter it was change this spring so no problem there but has a new one now. But the air sucking got me to checking, because the last filter change I had to pressure the tank with air to get fuel up there once there it was fine, this time that would not work, as soon as the air pressure is dropped the fuel backs off also.
So just went out and just barely cracked the vent and pumped the primer air movement up and down, as blowing and sucking back! this does not seem right to me, it would seem it should get its suction from some where else should it not?
Getting long already will put up an intro and a howdy in a later post for now hey!
Curt Acree
2001 Duramax
Edge Juice with attitude
4 inch exhaust
Still need cold air

That sounds like your primer bulb is damaged...

That sounds like your primer bulb is damaged...

Yes! pulled the top off and the neoprene valve had a small crack on the side which is letting things go this serious sucks, seeing as how cannot service this part, (go figure) got to buy the whole filter mount.
I may just mount an electric pump inline by the tank and solve a couple of problems, hit the switch and pressure up! They have a small pulse pump that is limited to 7 pounds but will feed a 750 Holley double pumper so should keep the Duramax happy I hope.

Yes! pulled the top off and the neoprene valve had a small crack on the side which is letting things go this serious sucks, seeing as how cannot service this part, (go figure) got to buy the whole filter mount.
I may just mount an electric pump inline by the tank and solve a couple of problems, hit the switch and pressure up! They have a small pulse pump that is limited to 7 pounds but will feed a 750 Holley double pumper so should keep the Duramax happy I hope.

That is probably what is going on with mine? I would replace the filter housing for sure. I run an edelbrock 1791 fuel pump. It is a flow through design so I don't need it turned on unless using high power.

That is probably what is going on with mine? I would replace the filter housing for sure. I run an edelbrock 1791 fuel pump. It is a flow through design so I don't need it turned on unless using high power.


I will look into the edelbrock pump the pulse pump I was thinking about using , I never even considered the fact that the diesel runs a continuous return so would probably not keep up on the flow.
May be what has been happening to yours I know mine has been doing the stalling thing since last February or so would start right back up but here the other day started right up moved a few feet and shut off. No fuel up front now can put air pressure in the tank and push it to the filter but as soon as the pressure is let up the fuel runs back leaving the injector pump side full of air, can't smack air:(
Now to spring for the filter mount or what ever it is called spendy lil bugger that it is, not sure if an in line fuel pump would keep things in place or not.

After talking to my local Lake city diesel ( a friend works there) they informed me that while a pump would help a working system it would not fix the problem.
They were of the mind that there ought to be a repair kit or something out there but after a day of searching through their parts system no luck was bummed.
Got the filter mount put it on pumped it up, cranked a bit lit up and quit, pumped some more and lit right up!!!! IT LIVES!!!
Will see if this cures the other or it rears its head again got it hooked to a 4 horse trailer now going to make a 120 mile trip Saturday to pick up a bred mare for the wife. Later

** Update **

Brought the beast in to a new dealership that said they have Diesel specialists on-hand. Explained the exact way to reproduce the problem and left them with the truck for a few days. They called me back saying they were able to get it to stall and captured a bunch of data with the Tech2. They sent the data in to GM, and GM replied 3 distinct failures are showing up. Tech inspected the main wiring harness and found 1 wire rubbed through (C107 terminal A4), and 1 wire pushed back (terminal A4 IGN Voltage 1 FICM). GM notified to also replace ECM. Luckily, the tech notified me this would all be under warranty ;) WooT... They kept the truck for a couple more days to test drive and ensure no further failures, and it was all good. Picked up the beast tonight and she purrs like a kitten now (ok... a kitten on roids) lol

Grand total:
8 hrs labour
987$ ECM
Total: 1687$
My payment: 113$ (100$ deductible +tx)

I'm ecstatic! WooT!

Great! glad you found it and it worked out in your favor! Mine seems to have been cured with the filter base, have not had a recurrence of the dieing fit since replacing it, Happy Dance!
Curt

** Update **

Brought the beast in to a new dealership that said they have Diesel specialists on-hand. Explained the exact way to reproduce the problem and left them with the truck for a few days. They called me back saying they were able to get it to stall and captured a bunch of data with the Tech2. They sent the data in to GM, and GM replied 3 distinct failures are showing up. Tech inspected the main wiring harness and found 1 wire rubbed through (C107 terminal A4), and 1 wire pushed back (terminal A4 IGN Voltage 1 FICM). GM notified to also replace ECM. Luckily, the tech notified me this would all be under warranty ;) WooT... They kept the truck for a couple more days to test drive and ensure no further failures, and it was all good. Picked up the beast tonight and she purrs like a kitten now (ok... a kitten on roids) lol

Grand total:
8 hrs labour
987$ ECM
Total: 1687$
My payment: 113$ (100$ deductible +tx)

I'm ecstatic! WooT!

AHHHHHHHHHHHH

Guess I spoke too soon... after 1 day of behaving, it's back to it's ol' stalling self again. Back to the stealership she goes.

Anyone wanna buy a slightly blown-up 3500?

Guess there were 4 problems and not the three they fixed!

Too bad. Hopefully, it will be found soon. But on the bright side, the initial fix was on their dime and not yours. Maybe this one will be too!

jb

My truck has done the same as yours with the stalling last winter and spring. The entire summer it ran great with no stalling. Now the other mourning when it was colder 32F, it stalled on me. When mine starts to stall I just flip on the lift pump and it comes back to life so its deff a fuel problem, the same as yours because your prime is low. After reading this and thinking about my truck we probably both have a leak somewhere. When its colder out the leak would be larger then when its hot and explanded. I think I'm just going to buy a new filter housing.

I've had only one no start this fall. It only took 2-3 pumps to get fuel. I also have a preCat filter and the rubber lines I originally installed are weather checked. I wouldn't suprise me if I'm sucking a bit of air there and at the OEM filter housing.

if the first few problems were wiring issues i woulds guess that this is the same sort of thing.. and a single stray wire can be hard to track down i have spend may hours tracing wiring harnesses looking for bare spots on some of out trucks im sure that the dealer will pick up the bill if they did the first time at least you dont have that to worry about

Bummer! That seriously sucks, couple of trips one pulling and around town which used to bring mine on still has not! so still hoping :)
Good luck with yours!
Curt

AHHHHHHHHHHHH

Guess I spoke too soon... after 1 day of behaving, it's back to it's ol' stalling self again. Back to the stealership she goes.

Anyone wanna buy a slightly blown-up 3500?

Sorry to hear that dude, I'm trying to get my truck in next week to have my stall fixed. It almost sounds better to just replace the whole engine harness.

I feel your pain!

Dealer was able to fix the problem finally!!!! I'm back to lovin my truck again lol. Fix ended up being a new ground harness to the glow-plug module. He also changed out the ignition relay (but he said that shouldn't have been it)... All said 'n done, about 500$ to fix it up (stupid labour lol). I couldn't be happier ;) And this time... I mean it lol

Still running good? I'm going in Monday so I hope this will fix mine. You have a part# for that ground harness?

Still running primo. Put about 500kms on her so far without a problem. Dealer slip has 2 p/n's listed. Terminal 12103507X and Fuse 15319478 (15$ total). The expensive part was the 4hrs debugging to find it lol. The repair description says "Repair G108 ground for glow plug circuit and engine oil level switch". Hope this helps you out.

I was driving home from OK this weekend while pulling my TT. I was driving at 65mph on CC and the thing lost power. I started to pull over to the side of the road and it started back up again and didn't do it again the entire rest of the trip. Any suggestions?