LLY: Loss of Fuel Pressure?

[hopkins_fam]

Well today my tough idle/lope cleared up, so hoped in the truck to go Christmas shopping. Trucks running great, half way through the trip i hit a hill and truck acts like Im not giving it any pedal. Fuel Pressure goes from like 12k down to 6k. Only does it on a hill, hit flat ground and pressure shoots to 18-20k.

I just grabbed a filter but any other ideas? Truck has a new FPR, head gaskets, MAP, DIY lift pump.

Could it possibly be pedal sensor or is CP3 taking a dump. All i have with me is muffler WatchDog and my Xcelerator. When i get home I'll put the Snap-On Solus on it and see what desired and actual is. Just trying to see what someone may have to say about it. No CEL's or Reduced Power either

 

[04D_MAX]

Care to elaborate on the DIY pump?

 

[adeso]

How cold is it?

 

[hopkins_fam]

Carter 3psi fuel pump mounted on frame rail in front if tank.

Its been between 35-40° today. I always run Howe's fuel treatment every tank. I always double or triple dose. The bmf bottle normally does 2-3 tanks for me.

The factory fuel filter head is gone (no fuel heater) i replaced it with a CAT filter head with primer bulb and water seperator filter.

 

[Kappa9012]

any issues with the draw straw in the tank? the fact that it does it on an incline makes me wonder if the fuel is sloshing away from the pickup tube.

 

[hopkins_fam]

I had to replace the factory filter head with a GMC factory unit a couple of months ago due to the inlet being clogged up with what looked like sand. Couple weeks ago i but the CAT unit on.

The truck was completely on full but after the sand discovery I've been wanting to pull the tank and check the strainer. I guess Im really just pissing in the wind til i get the Solus put on it. Bad thing is Im about 1.5hrs from the house

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[PureHybrid]

Monitor fuel return temp also, that will cause a derate.

 

[hopkins_fam]

Xcelerator shows like 109° on return temp i thought the rough idle/lope was gone but its still there. I just finished up shopping and headed to the house it hasn't down the fuel thing yet but still got about 40min of hwy driving left

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[PureHybrid]

What micron is your cat filter setup? I'd hate to say that the FPR is bad again but ya never know.

 

[hopkins_fam]

I hope not, if so its got a warranty through Alligator Performance. Well on The way home it didn't do it on a hill again but when i got close to hone i decided to punch it and it wouldn't kick down or increase desired fuel. Throttle shown 91%, and desired and actual was always very close so now Im lost.

Tomorrow morning Im gonna through the Solus on and see what she says. PPE was showing in park at idle 1.2MPH? What's up there, I got a used FICM ordered Wednesday to see if it fixed the rough idle.

If the truck was calling for more fuel than what it was making would that not have set a SES/CEL. Im thinking or hoping the rough idle and this is related. Here's a few snap shots of the Xcelerator when i got home idling.

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[hopkins_fam]

Tomorrow Ill log it with the Solus at idle and WOT and see if i can upload it. Im not sure what the Solus saves the logs/videos as.

The CAT water seperator came from a very large 4cyl CAT we run them on our generators and monster tele-Handlers as pre-filters. The base has 1/2" inlets and outlets its suppose to be 98% efficient at 4 or 6 microns. The filter is a 308-7298 if anyone can get any info in it

 

[hopkins_fam]

Only code was a P1093 i believe it was, Low Fuel Pressure while Power Enrich. When i got past half throttle on the hwy actual FPR shot to 0.

With it being Sunday nap isn't open so i can't get a replacement filter for my CAT head, if the rain slacks off Im gonna throw the OE head back on which has a like new 1500mile AC Delco filter on it.

If it is the filter Im gonna leave the factory head up front and finally buy a Nictane adapter and move my CAT head to behind the lift pump.

My only guess is start with the filter and go from there, I also went ahead and dosed the tank with Diesel Service 911

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[PureHybrid]

Have you checked fuel inlet pressure to make sure your lift pump is still in good shape?

 

[hopkins_fam]

Tomorrow im gonna buy a inline adapter for a fuel gauge with push style fittings on the end. The fuel in the bowl didn't look to good. Its rained like crazy today so hopefully tomorrow it'll clear up

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