[cbeese08]

I am brand new to diesels and I bought an 1986 C20 6.2 (J Code) last spring as a restoration project and have had hard starting issues ever since (seems common with these engines). Last fall, I developed a slow fuel leak, which eventually fills the valley and drips down. Truck runs well (for now anyway). Unsure if this leak is the IP or an injector(s).
1. I am curious as to how long you guys think I can run on this IP (primarily this is a weekend cruiser/sometimes drive to work/sometimes pull a small trailer truck)
2. I installed a check valve before the IP on the return line to stop from losing prime, which has worked and she now starts right up, but I know that’s a band-aid. Would this indicate that my hard starts are related to this leak or is it possible it’s still the box filter?
2B. Does this check valve increase risk for runaway or some other type of catastrophic engine failure?
3. Would anyone recommend a seal kit over replacing the pump if that’s necessary?

Light to moderate insults are welcome, so long as they eventually lead to helping me get “Derty Gerty” running and starting as she should.

 

[OkDually]

I am brand new to diesels and I bought an 1986 C20 6.2 (J Code) last spring as a restoration project and have had hard starting issues ever since (seems common with these engines). Last fall, I developed a slow fuel leak, which eventually fills the valley and drips down. Truck runs well (for now anyway). Unsure if this leak is the IP or an injector(s).
1. I am curious as to how long you guys think I can run on this IP (primarily this is a weekend cruiser/sometimes drive to work/sometimes pull a small trailer truck)
2. I installed a check valve before the IP on the return line to stop from losing prime, which has worked and she now starts right up, but I know that’s a band-aid. Would this indicate that my hard starts are related to this leak or is it possible it’s still the box filter?
2B. Does this check valve increase risk for runaway or some other type of catastrophic engine failure?
3. Would anyone recommend a seal kit over replacing the pump if that’s necessary?

Light to moderate insults are welcome, so long as they eventually lead to helping me get “Derty Gerty” running and starting as she should.

Welcome

I would first address any and all issues with the fuel system. ( ie. leaks in the valley, etc. )
Diesel engines are unlike gasoline engines. A gasser can be more forgiving when it comes to leaks whereas a diesel cannot tolerate any fuel system leaks.

Go through the entire system from tank to the Injection pump and fix all issues. ( dry rotted rubber fuel lines, rusty/corroded steel lines, etc.)
The Fuel system needs to be rock solid.

 

[cbeese08]

Ok. I was planning on replacing the box filter with a spin on and all the rubber lines up top. I guess I’ll check the hard lines too

 

[OkDually]

Ok. I was planning on replacing the box filter with a spin on and all the rubber lines up top. I guess I’ll check the hard lines too

The box filter is a known leaking problem. Upgrading that with a quality unit like a Racor filter unit will help.
You may have to pressurize the fuel lines to help find any leak sources

 

[cbeese08]

I lucked out and found a NOS one from a ‘96 Savanna van. I wanted to keep my WIF light and fuel heater. Hopefully it’s high quality enough lol

 

[The Grinch 77]

The rubber line from the box filter to you injection pump could be your fuel leak.. was on mine. Also good batterys , cables, and starter are the secret to a great starting 6.2 in any weather. You also beed a good glow plug system. When you have working glow plugs and it spins over as fast as intended they start well!!

 

[The-Real-JCDiesel]

Ill be nice since you are a newer owner. I've been through quite a few gm diesels 80s and 90s repaired and rebuilt complete fuel systems from tank, strainers, sending units, lines, fillernecks, lift pumps, filter housing swaps, injection hard lines, return lines, injection pumps, injectors, and even modded some fuel caps. My point being is that you have to properly diagnose the leak. Nobody here can tell you specifically what is wrong or where the leak is coming from. Only you can know that. I would advise a thurough inspection with flashlight and all. Probably will have to remove the intake which is not hard to do. There is a good thread on how to lightly pressurized the system and inspect for leaks. I will look around for it. Good luck to you.