Need help with a hesitation issue on a 2015 LML.

6lhoss

New member
Jun 11, 2021
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So I'll give the back story first. My truck is showing zero codes. Issue isn't consistent sometimes it will go a day maybe 2 days no issues. Sometimes it will go 30 to 50 miles then issues occur still no codes.

The issue when it happens. Is as follows.

The truck sputters when driving at 1500rpm to 2500rpm like poping and sputters. Basically how a truck would sound with mass airflow sensors unplugged. Almost like it's running out of fuel. But just in the 1500rpm to 2500rpm range which is horrible because that's normal Driving range. If it starts sputtering if you go wide open thrott and Go over 2500 rpm the truck is fine and has full power. Until rpm drop under 2500 to 1500 then once load load is applied. Truck starts to sputter again till wide open throttle.


Problem started after fuel filter change. The WIF had a small crack and was leaking so I put a new one on. The leak stopped issued was a little bit better but not completely gone. Issue started to get worse so at this point I definitely decided to change fuel filter. New filter same issue was still there. So I changed the lower mass air flow sensor and the problem went away for almost 2 days . Now the issue is back worse then it has ever been. Truck is driving just not well between 1500 and 2500 rpm. Also another weird part is the issue almost completely goes away if using cruise control. So I am wondering if it could be gas pedal sensor related 🤔 but still no codes so I am at a complete loss on what to do next.



Any help would be greatly appreciated thanks everyone!
 

Dive!Dive!

New member
Jan 26, 2021
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Have you considered rebuilding your fuel filter housing assembly?

I had similar issues after replacing my fuel filter. I was a little suspicious of the primer seals. I was able to get a good enough prime to run the engine, but noticed that after a day or so, when I would push the prime pump, it almost felt like there was no prime in my lines.

Anyways, bought the rebuild kit from MA https://www.merchant-automotive.com/Deluxe-Filter-Head-Rebuild-Kit-LML-2011-2016-Duramax and no problems since.

Just a thought.


2016 GMC 2500 CCSB SLT
6.6L LML DURAMAX
S&B Cold Air Intake
AMSOIL Bypass Filtration System
Kleinn Train Air Horns with Onboard Air
Autel Scanner MaxiCOM MK808
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Ron Nielson

Active member
Oct 11, 2009
773
147
43
Berryton, KS
So I changed the lower mass air flow sensor and the problem went away for almost 2 days .

You have a lower MAF and (implied) upper MAF?? Or just typo?
I hope your MAF replacement was with an OEM, not an aftermarket one. You COULD have a problem with the MAF circuit (or some other circuit affecting fuelling) where there may be a dropout or loss of ground. Also, if you used an ACDELCO fuel filter, some have reported problems with those recently, probably caused by a change in the actual filter manufacturer.