Hello all. I have a 2015 Chevy 2500, Dmax/Allison, 320k miles. i fired it up this morning and it ran like crap, was running like a top when got home last night, would not idle at all. it had a #1 gplug code so i threw one in right quick. it helped the idle, it has a long start (3-5 sec), but will idle fine. as soon as you touch the pedal it just goes to crap, it stumbles horribly and will not raise rpm. i just replaced the entire fuel system a cpl yrs ago when the inj pump grenaded, new pump, injectors, lines, and tank was pulled and cleaned out. i put a FASS pump on it immediately after to help take strain off new pump. there was quite a bit of white smoke when first started but has gone away. i let it run a while because i changed all the the fuel filters while waiting on gplug, hoping it was just air in the lines but after 20 min of idling its no better and exhaust will burn your eyes like its running rich. i dont know much at all about diesels but my local diesel guy (same shop that replaced fuel system before) says it sounds like same problem. ofcourse the warranty JUST went out on the parts. but a new injector pump backed up with positive pressure from the fass i would think would outlast the original, or atleast more than a cpl yrs. he also said for an extra 1000 (8k instead of the 7k i pd for the first fuel system replacement), he could put the old style pump on it that "will never go out"... well why wasnt that offered the first time. anyone have any thoughts on this?
CK5
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Duramax idle only
- Thread starter WALREC
- Start date
Hmm. Have you done any diagnostics to prove the stock pump using putting out the pressures it needs? Typically with the right scan tool you can command fuel pressure up and watch the actual vs desired. They should go up together as you go up. A weak pump would obviously not hit the desired target pressure when commanded.
Though you could have a fuel pressure regulator dumping fuel back to the tank too.
Seems to me that the dude is just ready to fire the parts cannon at your truck on your dime.
Though you could have a fuel pressure regulator dumping fuel back to the tank too.
Seems to me that the dude is just ready to fire the parts cannon at your truck on your dime.
I'm swapping out a 2012 lml for a guy right now, his blows tons of white smoke and we are pretty sure it lost an injector while he was towing and took out a piston. Only like 50 psi of compression in one cylinder.
That kinda sounds like the egr valve is stuck open,that will cause the symptoms you describe. If that's been deleted then disregard.
You need some scan tool data to start to diagnose this, desired vs actual fuel rail pressure,maf gr/s ect,ect.
You need some scan tool data to start to diagnose this, desired vs actual fuel rail pressure,maf gr/s ect,ect.
well friends, i appreciate all the info. i havent had alot of time to fool with it, but i got out there this morning and found the issue. bottom line, the wife is no longer allowed to drive my truck. for the first time in 23 yrs of marriage that she actually does NOT bring my shit back on empty, she puts gasoline in it. not sure how i didnt notice it when i changed the filters the first time, but when i pulled one back of this morning the smell was apparent. i froze for a moment while i processed what i thought couldnt be. i looked down in the filter to see a bright golden liquid instead of a blue tint and my heart sank. after a short calm (relatively calm) conversation with the wife, i used the fass to empty tank into buckets and will be dropping it after lunch. gonna go get some more filters and bleed the lines out as much as possible once tank back in and hope the gas hasnt washed it out too much. will be adding atf for initial start up,, i just hope its not too late. will update once done.
Oh no…
It will probably be fine. I see 3-4 of those a year. No need to drop the tank,just pump it all out and fill with fresh diesel.
Fingers crossed for you man!
Could have been worse. Had a customer dump def fluid, 5 gallons worth into his diesel Colorado. That by itself sucks but that yahoo drove it to the end of his block with it running like crap the entire way.
Def fluid is water based and corrosive to the goodies inside a diesel injection system. Gm protocol was to replace 100% of the fuel system. On his dime too.
Def fluid is water based and corrosive to the goodies inside a diesel injection system. Gm protocol was to replace 100% of the fuel system. On his dime too.
Seen that on a semi once. Crystallizes and ruins everything.
It’s nasty. The guy couldn’t wrap his head around it. Screamed at me to just drain the fuel tank and it will be fine. By the time I added up all the parts and labor it was going to be over 10k to do the repair per gm guidelines. He might have had the truck for a month when he did it.
Ouch!
well guys I think i dodged a bullet. i took your advice Jake, just topped it off, also dumped in a qt of atf. it took forever for the fass pump to prime, if i recall, it didnt take no time at all to prime when originally put in. nevertheless, its primed and pumping and the engine is running like a top again, no miss no smoke. gonna change the oil first thing in the morning and drive the shit out of it. i appreciate all the info guys!
Glad to hear it!
