My truck starts but breaks down under a load . Like 1 or 2 cylinders are not happening the engine runs rough. changed fuel heater. what about the injecters/ Fuel is fine . installed lift pump last 6 months.also the injector pump. trucks got 250 thou miles.

 

Do you have a fuel pressure gauge?
Sounds like you are not getting enough fuel to the pump...
Did you check for codes in the odometer window?

 

no fuel gauge . no codes. is there a diffrent gauge for diesel

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or is the fuel gauge for gas ok

 

What is your fuel pressure? How much of a load? bed loaded, pulling a trailer, etc. What mods have you done??

It could be your APPS, the VP, a bad ground, another bad lift pump, etc.

 

On a 24 valve Cummins with a VP44 injection pump, it is imperative to have a fuel pressure gauge. Lack of fuel supply to the injection pump is disastrous as it depends on the fuel for cooling and lubrication. My guess is lack of fuel pressure at this point. You can get a cheap fuel pressure gauge at Autozone or the likes for initial testing, but I would highly recommend getting an in-cab pressure gauge so you can monitor pressure at all times.

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Where are you located? Could it be a gelling issue?

 

thank yall so much. sounds like i need a fuel gauge. will a gas fuel gauge work?

 

You need a fuel pressure gauge. A cheap one from Harbor Freight/Autozone will work. A "Fuel injection pump tester" from Harbor Freight will attach to the schraeder valve on the injection pump to see how much pressure you have.

 

I would recommend getting either an Autometer or ISSPRO gauge. If you use either an electric gauge or an isolator, it won't matter much which type you have. You need a gauge that will read up to 30 PSI ideally.
You can purchase a gauge directly from one of the vendors on this site, they are helpful and reasonably priced. All you need to do is request a price quote here:
https://www.dieselbombers.com/price-...request-price/
They will set you up with everything you would need for the install.

 

the best way to find out if injectors are shot,crank truck,crack #1 fuel line,if the motor starts missing and laggy tighten it back its good.keep doen this an when you come to a line that you cracked loose an the motor has no changes an it is missing like its been,then the injector is bad,do all six,an replace all six when you do.