Been sitting, now won't start

[tom lovinggood]

Hello--'68 CUCV Blazer in great shape. Has been sitting for three months. I went to start it this morning. Plenty of juice to turn motor over. Ran for about 15 seconds, then died, and would not start after that, even though the engine turned over. Have almost a full tank of gas. I am thinking this must be a fuel delievery problem. Anyone have any thoughts? Thanks in advance

 

[Barrman]

Probably an air leak somewhere in the fuel system. Cracked hose or fuel filter most likely. How long did you try cranking after it died? One of my trucks will do that every few months. 10 seconds of cranking, sit for 2 minutes, repeat. Normally fires back up again after the 5th or 6th attempt.

 

[sandcobra164]

My truck experienced a similar failure that turned out to be an injection pump failure with the similar symptoms as yours. Mine would start, run about 30 seconds, idle up and stall. After some labored cranking it would re-fire and run fine for a while. I was thinking air in system as well. My issue may not be yours but I went with cheapest to most expensive in my diagnosis. If you read through some threads on here you will notice a somewhat constant theme. The factory fuel filter base is prone to cracking AND on mil trucks only there is a sensor on the lower half of the filter base that is prone to fail and leak causing the truck to lose prime. My first attempt at fixing the issue was to install a spin on fuel filter assembly along with new fuel hoses. Swing and a miss, strike 1. I then read around a little bit and found the issue could be a plugged injection pump housing pressure regulator. That's a fancy term for the return line fitting from the top of the injection pump. I cleaned mine and the issue was happy for a short while. Since the issue came back I replaced it with a new one. Short term fix but the issue came back. I temporarily fixed it by drilling out the glass checkball inside my old injection pump housing pressure regulator but also read how that's a very temporary fix which has the added con of messing with injection timing. Swing and a miss, strike 2. I then read some more and removed the top cover from the injection pump. Turns out I was experiencing an issue of creating tiny specs of black rubber which comes from a failing elastomer ring inside the injection pump governor assembly. I replaced the injection pump and Swing 3 at the bottom of the 9th with 2 outs and bases loaded made my truck run like a brand new one again. I'd suggest you troubleshoot in somewhat the same order and hope you can fix the issue on chasing an air leak. I wish you Luck. I used a HMMWV injection pump for a 6.5 N/A which is why the top cover looks different in the first 2 pictures. The stock top cover will need to be retained if you go that route.

 

[DeadParrot]

A couple often overlooked pieces of fuel hose are the one from the tank sender to the metal frame line. And the one from the metal frame line to the fuel pump. Unless you have an in tank fuel pump, both hoses are under vacuum and won't leak much fuel out but will let a lot of air in. Plus that nice cozy space between the top of the tank and the body/bed can say 'home' to a mouse. And mice will chew fuel hoses.