Fuel going into the engine - 843 with Isuzu 4JB1 - Now what?

[ks_dave]

My old 843 has been like a right arm, but I've been fighting low fuel pressure longer than I want to admit. It had gotten to the point where it would idle back to about "half-stick" within 30 seconds of starting. I could pump the bulb (never really getting hard), and rev it, but just for a few seconds. After replacing most everything between the tank and the pump, I FINALLY pulled the dipstick. It's at about twice the oil level that it should be. Sounds simple now, but I just couldn't see it before. I finally asked myself why if I could pump like that with the engine shut off, I couldn't actually see any leaks.

Anyway, reality is hitting hard. She's an old girl, never failed when I needed her. No telling how hard she'd been worked before I got her. But now…well, I have to something, but what?

I'm a fair shade tree mechanic, but this one is outside of about any of my experience. I see replacement zexel pumps all over, most probably Chinese, anywhere from few hundred dollars to over a thousand. Which to buy, or is a rebuild a better option, and if so what should I expect to spend? And the way I read the manual, it takes special tools (and probably skills) to replace it. Can it even be done without pulling the engine?

Figured I really should ask people who know rather than trying to figure it out in the middle of the night. I'd appreciate it if someone who has done this can set me straight.

 

[Tazza]

You're running a perkins?

I'd lean towards the issue being a bad lift pump, if it's not part of the injector pump, just install an electric lift pump and by-pass the mechanical one.

It is not unusual for a pump to fail and makes you make engine oil.

 

[ks_dave]

No, it's an Isuzu 4JB1. As I understand from what I read, and interpret it's appearance, it's a single unit injector pump assembly made by Zexel. Unfortunately if I read it correctly, I can push fuel with an electric pump, but don't see a way to bypass the leak. I'd love to be wrong.

 

[Tazza]

Sadly i think you're sending your pump off to be repaired.

 

[ks_dave]

That's what I think, but I've been unable to find even in the service manual what it takes to get it off, and it looks like it may take special tools to get it back on. I was hoping someone who has done it can share that experience, and maybe offer a trusted place to repair or buy from.