Okay, so for the last few weeks i have been trying to figure out what is wrong with the truck. when the truck is cold it will idle fine, but after awhile it will start to have a lope in it. I can look at my rail pressure gauge and it will slightly change with the lope of the idle. Does this sound like a FPR or injectors? I do have dual pumps, so is there anyway to check them out?
LBZ: random fuel issue
- Thread starter Chucky797
- Start date
i went to take it for a decent spin to see what the rail pressure is doing. When i get into it i can see it bounce by up to 5k. Does this sound like a sensor? I do not have access to any of the scan tools, unless an autocal can look at desired vs actual? If it comes down to it I will have to take it to diesel addiction to have them figure it out for me.
Previously somebody suggest Bio diesel! I will recommend stay away! Bio diesel got ,,live cultures in fuel. if you not driving it every day it will clog your fuel filter and fuel lines with same shit like when you got fish tank and you do not clean it or have no fish so you developing kind. green grim on side fish tank!
My other question, since I have two pumps I know I will need two sensors. If I replace one to see if that is an issue will it stop doing the fluctuating? That way I know they both went bad and can do the second one after?
I would remove the belt and run it on the factory position CP3 and see if it lopes and decide from there.
^ will that just help me determine if I need one or two? I thought the way the dual pumps work is if one falls behind the other can pick it up. If they both work they would split 50/50. If both sensors are bad, and I replace the first one it should be able to pick up the load. Am I looking at this all wrong?
They are splitting the load but if one has a sticky/failing regulator it will make the truck lope regardless of what the other is doing. Also when you unhook the belt be sure to disable the dual pump control, IIRC I have heard of the control failing and causing lope/power issues as well.
Now I am in a bind, I have been trying to figure this issue out. Well today I got a check engine light and the truck is showing low rail pressure. Since I have to order a sensor, can I run my truck with the fpr disconnected, or will there be adverse side effects besides injector knock?
It finally acted up again, will that pump be okay with the controller disconnected to the second pump. That one should max out and run it, right? Will it harm anything?
Well I was able to check the engine code finally. I am getting p0191, Fuel Rail Pressure Sensor Circut Range/Performance. Where should one start on figuring out this issue?
Obviously you have a bad fpr . if you unplug the for sensor it will be commanding full rail pressure which is not good for the fuel system. Doesn't seem like you've tried anything the other guys have recommended!
So I was able to replace my fpr but I am still having an issue. It will hold decent rail pressure but when I hit a bump in the road it will bounce as well. Also when I am coming to a stop the pail pressure will drop then catch itself when i stop moving. Where should I look at next for an issue?
Made some progress, it seems that a wire that is around the fuse block area is bad. Looks like next weekend I will be looking at wiring diagrams and going wire by wire.
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