Cummins N14 Stumbles on light acceleration

Does your truck have a Davco Fuel Processor?

 

I just fix this exact same problem on my 2000 Volvo with an N14.

Mine had a galled injector, ended up replacing all six. Also had a crack in the return line going back to the tanks and also had a bad Davco fuel filter assembly.

The last two were causing long crank issues.

They also blew out the plate behind my ECM, they found a little bit of debris in there.

Truck runs very smooth now much better and starts quicker

 

The check valve in the cooler plate can be disassembled without removing it. After removing the line you can grab the end of the fitting where the line seats. Give it a slight twist & pull out straight. It's held in by an oring. Be careful the small spring doesn't fall out. After removing the spring the check valve will slide out.

 

Most injector failures are mechanical not electrical. If it's an electrical failure the engine will only rev to 15-1600 rpms & the check engine light will be on. A broken pass thru connector in the rocker housing is a failure you see once in a while. Find a shop with the Insite program & it should be easy to diagnose.

 

It could be air getting into fuel supply system.

 

Speaking of N14, does anybody know why on idle it won't blow hot air, but when you rev it up to over 10rpm the heat starts working again?
When driving it's fine. Water pump?

 

Low fluid level. Bad thermostats, if your t-stats stay open, your coolant doesn't get hot enough.
Does your engine fan stay on
Cover your radiator to retain heat/prevent cooling air from flowing thru the radiator.

 

That's what's weird, the temp is good, stays around 180 like it usually is.
I did have a similar problem before and on that truck,and like you said, covering radiator helped, cause temp would not go up, but this one is something different. I'll double check the fan

 

Your temp at 180 is your block temp. But you don't know the volume of flow out to your radiator.
I think if your water pump is not working, your truck would be overheating.
My old cabover I had to use radiator cover and I had a Volvo that needed a cover.
My current truck needs no cover, even down to -20. It has N14