96 Chev 2500 Silverado Error codes

[Roadrunner1]

Getting the following codes on the above truck with 169K Kms
Thinking it could be the Injector Pump but looking for some direction
Codes are PO251, PO335, PO370
Symptoms on the truck are stuttering, Hard starts occasionally stalls out at idle.
New to Diesels in trucks but worked on Farm 6 cylinder Diesel tractor before
Will take to shop if necessary but like to know what I am in for before they see me coming!
Any help would be appreciated.
RR1

[joed]

P0251 is Injection Pump Cam System, P0370 is for Timing Reference High Resolution, and P0335 is for the Crankshaft Position Sensor Circuit.

Both the P0251 and P0335 are related to the Optical/Fuel Temperature Sensor on top of the Injection Pump (IP), so it's possible this sensor is faulty and this pretty much requires a new IP to replace it.

Since you're also getting a code for the CPS, you could have a voltage and/or ground problem. I would check all your connections and clean grounds to rule that out first. Also, some have had success just unplugging&replugging the connectors to said sensors, engine harness along the firewall, and the PCM. Sometimes this can clean/restore a bad/intermittent connection.

Hope this helps.

Joe.

[Roadrunner1]

Talked with my local Mechanic and he thought it might be the sensor on the injection pump. Apparently there is a kit to move the sensor off the pump and onto a cooler location in the engine bay. Also could be air getting in fuel system via bad seal around fuel filter.
Bad news is the kit is not cheap Like $600.00 plus labour
RR1:eek:

[gmctd]

Check with HeathDieseldot com and doityerself for a permanent fix

Also check the fuel and air filters, and lift pump operation - put a low-pressure guage on the water-drain hose, run the engine, open the drain to check for ~4psi fuel pressure at idle

Fyi, these DTC's pop up every year at this time as winter lays about with a frosty bite, and again in late Spring as the climes turn summer'y - time to clean the batt's and grounds and connectors, run 8oz powerservice additive and 8oz ashless 2-stoke TC-W3 ashless motor oil per each tank of #1 ULSD, sorta like the croatin oil\codliver oil yer grammaw used ta give ya every winter and spring

If that don't clean it out, you'll need a replacement IP

And, BTW - welcome to the 'Page, RR1............