Bought LB7 04/13. Won't start 04/16.

[robstu85]

Bought my first diesel 04/13 and thought I got a true gem; a 1 owner 2003 2500 LB7 with 76k miles from an 85 year old man. 3 days later I can't get it to start.

Some background. When I went to show my dad the truck before I bought it, it started for 3 seconds then died. Owner said could be cause I don't run it much anymore. Went to pump it from fuel filter housing, bleeder was stripped. I said when he gets it running let me know. He called, said he put in a Nylon screw and got it running. Said it should work fine.

Bought the truck, drove it home, drove fine. Next day (4/14) got it registered/insured. Took it for a 15 minute cruise to enjoy my new rig. About 2 miles from my house, had almost no power to get up hill, black smoke rolling out. Check engine light came on momentarily. P0087. Felt disgusted. Went to bed.

Next day (4/15) started up. Reset code. Went out and bought some Hot Shot Secret Diesel Xtreme. Put in about 8oz for half a tank. Figured maybe there was some clogging from lack of use recently. Drove all day on many errands. 8 +/- starts stops with no issues. Seemed to be a little hesitant if I really tried to push the pedal down, so didn't push it; wanted Diesel Xtreme to do it's work. Parked. Felt good, slept better.

Next day (4/16) no start. Turns over and over, no fire. Tried pumping fuel filter housing; doesn't help. After a couple pumps I open the bleeder and fuel comes out. 4/17 (today) same thing. I ordered a new bleeder screw from NAPA and will pick up today, but after reading dozens of forums and watching dozens of videos, I don't know that that is going to help. I am considering fuel filter and/or head rebuild kit (https://www.dieselpowerproducts.com...er-head-rebuilt-kit-01-10-66l-gm-duramax.aspx) as I am hoping it's an air issue. The black smoke has me worried though as I think that means running rich/lack of air.

Any thoughts would be appreciated. I also apologize if any of my lingo is incorrect. I am learning all of this, including the heartache, of the Duramax. I will update if anything changes after the bleeder screw.

Forgot to mention, owner said fuel filter replaced April '22. No way it's close to 10k miles, I'd guess like 1k.

 

[2004LB7]

Does sound like a lose of prime issue. Probably best bet is to get a new filter housing, water in filter sensor and replace the filter, be sure to use a parker racor PFF50216 (or dealership one) filter and making sure the O rings are seated properly

You can try the housing rebuild kit but sometimes the housing developments hairline cracks and the rebuild won't help that. Also those nylon bleed screws are junk. I like the metal ones. I've also been able to prime the fuel system without opening up the bleed screw many time without problems. So, because the nylon ones strip out or break easily I just leave it alone.

Lastly a lift pump will go a long ways to elevate this issue in the future. Might be wise to look into one

Oh, and welcome

 

[Nate’s Dmax]

Welcome. Jason said it very well. The lift pump is a must.

 

[robstu85]

Put in the new bleeder screw. No luck, just continues to turn over with no spark. Attempted to prime and start, also no luck. Took about 10 pumps before it felt "full". Opened bleeder and fuel came out fine, no bubbles or anything that I saw.

 

[TheBac]

Could be the rubber lines are getting old and leaking air. Could be you have an air leak at a hard line connection from the tank, too. You'll have to add some air pressure to the fuel system from the tank inlet and then look for any pin-hole leaks in the lines to the engine and around the filter.

Last thing, could be CP3 took a dive. But we dont want to think about that yet, right?

 

[Bdsankey]

What is rail pressure doing while cranking? IE what is actual and desired?

As Tom said, a quick and dirty method is to jam an air blow gun with a rag in the fuel filler neck and apply a little bit of air pressure. Sometimes the soft lines near the driver side valve cover also collapse and can cause a similar condition but usually they don't prime up when the line collapses.

 

[robstu85]

I'm having it towed to a local diesel mechanic that seems to be knowledgeable and have a good reputation. Any more troubleshooting would have just taken me out of my comfort zone. I appreciate the input and will update as I learn. I'm also considering having a lift pump installed while it's there.

Robert

 

[Dozerboy]

Congrats on the new truck sorry it's not working out so well so far.

Probably a wise choice to take it to a shop. You might want to run by us if they are saying it's a major repair. Get specific details on why they say those repairs are necessary. Some shops love to say injectors, Cp3, or ect just because they are to lazy to troubleshoot it properly.

I would almost bet on fuel lines.

 

[2004LB7]

Even a simple clear hose in place of the fuel line to the CP3 can tell you a lot. Bubbles or air in the line will be visible if the filter housing or fuel lines are leaking.

 

[robstu85]

Mechanic told me that it's not getting fuel pressure; he checked with a diagnostic tool. I don't remember if he said he checked for air leaks or not. It was a very early check just to get an idea as he hadn't even brought it in the shop yet. He did get it to run with some type of starter fluid, but it wouldn't stay running. His first thought is that it is the fuel pressure regulator, but he had to do some more diagnostics to state that with confidence. He's got a parts LB7 he can pull from, so I'm hoping that I can get a fix without a wallet full. He sounds like a straight shooter and knows what he's talking about. He actually had another LB7 on the rack when I talked to him. Get in line I guess.

 

[2004LB7]

I doubt it's the regulator. At least not with your symptoms. He probably hooked up to the OBD port and looked at the desired and actual fuel pressure and seen that it was zero. Air in the lines will do the same thing and that is much more common

If you are planning on getting a lift pump, maybe you can have that installed first and see if it starts before having him spend several hours replacing the regulator

 

[Dozerboy]

I would avoid used parts. Especially regulators that do go bad anyways. Unless he is going to warranty them.

 

[08lmm72mm]

I would tell that mechanic not to use starter fluid.

 

[Bdsankey]

I would tell that mechanic not to use starter fluid.

When used properly it's not a problem, it becomes a problem when people use gobs and gobs. It's can an incredibly valuable tool for diagnostic.

 

[2004LB7]

When used properly it's not a problem, it becomes a problem when people use gobs and gobs. It's can an incredibly valuable tool for diagnostic.

I actually prefer regular unleaded gasoline instead of ether for starting fluid on a diesel. Doesn't rattle and sounds much more gentle. Just a spoon or cap full down the intake is normally about the same as a good squirt of ether

 

[LBZ]

Those rubber lines going from the frame hardlines to the ones on the engine are known for going bad internally too. 20 y/o truck I’d be looking at stuff like that before spending big bucks on regulators and pumps etc. I’d start by rebuilding the filter head and if it still acts up hook up a jerry can to the filter inlet and see what happens. It’s mostly hard parts and a few short hoses after that which helps determine which end of the fuel system needs diagnosis.

 

[robstu85]

Update: Mechanic tested lines with air, no issues. Tested fuel pressure regulator and said it's fine. Says it's the CP3. Looks like it'll be about $1,500 parts/labor using a remanufactured Bosch unit. I trust this guy since he was a GM diesel mechanic. Let's hope he's right!

 

[TheBac]

I hate being right.

 

[Bdsankey]

I hate being right.

I bet your wife says the same thing but probably more like "I hate when you're right.................."

 

[TheBac]

I bet your wife says the same thing but probably more like "I hate when you're right.................."

Oh hell, in that situation I'm never right.

Remember,
Rule 1 - Wife is always right.
Rule 2 - If Wife is wrong, see Rule 1.