Peterbilt 386 starts and dies immediately

[shawn21998]

(10-25-2023 )shawn21998 Wrote:  

(10-24-2023 )Rawze Wrote:  cranking up and then stumbling out sounds more like a fuel issue to me... but one never knows when they are just guessing at it on a forum...

fuel pump acting up or going out?. - Has anyone bothered to pull the fuel pump head off and inspected the plungers, rollers, cam, etc?.



Performed a plunger test to ensure they are not sinking ... and Also pulled them put and flipped them upside down to see if they go into the holes upside down, to ensure they are not not flared out slightly at the tops, causing sticking when operating?.

Initially I was thinking fuel issue but the batteries were at 8v so I installed new batteries and still got low voltage code as only active code. Someone replaced the solenoid on the back of the pump so I checked wiring from that to ECM and insured resistance is within specifications. I am open to ideas but not sure how to perform plunger test. The way the truck fires right up initially is what lead me to believe its a voltage issue at ECM. Truck acts like you just turn the key off after it fires up. Is there any fuel pressures I should monitor before pulling the head off the pump?

I have the head of the pump off. Performed all inspection procedures outlined in the cummins service manual. Insured plungers extended with shop air, inspected springs and retainers and removed. Performed plunger test and insured they are not flared out. Rollers, tappets, and camshaft all look great.