Fuel Filter Minder Issues 08' LMM

[Burn Down]

My Dads 08 LMM has been having an issue with the fuel filter minder in the dash going from say 80-90% to 0% within a mile or 2 of pulling a grade. He can reset it and it will go back to reading 100% until he pulls a hill again. He has changed the filter & the truck doesn't have low power issues... Is this normal or not? My dumb llily doesn't have any of that new fangled mumbo jumbo

 

[Kappa9012]

mine would do that with a bad filter, or when It was tuned before I had a lift pump. The ecm does not have a delta p sensor on the fuel system pre and post filter, so the only thing it can be using it desired rail pressure vs. actual fuel pressure. how many miles are on the truck? wonder if its a bad cp3, or maybe a bad pickup in the tank sucking air? My truck would not always throw a low pressure code or really lose power.

 

[Burn Down]

Ehh, it only has about 285,000 miles.... I need to get home and mess with it. To hard to T/S over the phone and he doesn't know what he's looking at. I was curious if it had a sensor or not, thanks.

Read somewhere LMM has some collapsing fuel line issues???

He bought it used I might add, so he wasn't sure if it was normal or not.

 

[RitzBlitz]

Yeup, my first thought was fuel lines. Right where they bend up at the firewall is the problem area IIRC.

 

[Ming15237]

Our fuel lines on our 2008 lmm collapsed at the firewall and down by the transmission, with right around 100k miles. So I would surly check them lines. I would also go the rubber hose repair kit route vs replacing the whole line assemblies unless the steel lines a re all rusted to the point of near failure anyways. Also take a peak at the lines where they connect back at the fuel tank, I have seen them collapse as well.

 

[NC-smokinlmm]

Yeup, my first thought was fuel lines. Right where they bend up at the firewall is the problem area IIRC.

This^^^^

Mine did it as well. Easy to fix, just cut the hard fuel line on the inside frame rail and run new line all the way to the hard line on the divers side of the motor. This way you route around the troublesome factory lines...

 

[Kappa9012]

mine did as well actually, weren't completely collapsed but enough that I replaced them with hose and clamps... under the cab looked fine though.

 

[Burn Down]

Finally got home to look at this... You guys were right:thumb: Fuel line had kinked in two spots at the quick coupler on the left rear of the engine. Airdog and 6.4 ford airdog fuel lines from the tank to the engine, problem solved.