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JerryLook · 03-03-2021, 05:43 AM

Hey thanks for posting that. I saved it for future reference

n2zon · 03-03-2021, 06:13 AM

Diesels are pretty new to me, so maybe I'm all wet, but...

Some posts discuss measuring the fuel pressure at the injectors and cracking the connection to see whether fuel is getting there. Maybe I'm just a Nervous Nellie, but I'd exercise extreme caution doing either one. Our ISL's common rail system runs at 36,000 PSI if I recall correctly. At some point the equipment to measure this pressure safely might exceed the cost of bringing it to someone qualified who already has it. Out of curiousity, I did a short search. Just the gauge is about $1.5K without appropriate connectors and such.

I'm trained for handling high pressure gases, and they can be hazardous enough, but they're still an order of magnitude lower than diesel injection pressure.

Taking the injector line completely off might be safer. I suspect but do not know that the injection pumps can't make enough volume to reach full pressure with a disconnected, open line. I'd ask someone who knows first.

JerryLook · 03-03-2021, 06:31 AM

I’m definitely a big diesel noob. The only diesel maintenance I’ve done is to my Ford and my dads JD tractor.

I don’t watch TV, but I do watch a lot of vehicle and heavy equipment maintenance stuff on YouTube. The thing I’ve noticed about cracking the injector lines is they say you can put a wrench on the line but don’t try to tighten it with your fingers. Since yes the pressure is very high.

But, I need to get low pressure going to the caps pump first before I check for high pressure from the injectors. I’m going to check a few things today before I go to work. Waiting for the DW to get up so I don’t wake her up when Im banging around with some wrenches

JerryLook · 03-03-2021, 07:24 AM

So the first thing I tried is to connect a diesel can before the primary filter. The lift pump starts to suck fuel out of the can, but it can barely even suck the fuel out. And as soon as the pump turns off all the fuel drains back to the can right away.

Basically for the first part of the lift pump cycle it’s not sucking much. After the tone changes it starts sucking a little more, but not enough to prime the system.

I’m going to try the same thing before the secondary filter. I’m going to pickup those torx sockets today and take the lift pump apart also

JerryLook · 03-03-2021, 07:36 AM

Does it go?

Primary filter > lift pump > secondary filter

JerryLook · 03-03-2021, 09:23 AM

To answer my own question, yes it does.

Fffrank · 03-03-2021, 10:11 AM

You have a lot of things to rule out but this sounds/feels like the same issue I had. The lift pump can't push it through a failed ICV so it never properly primes or purges air from the system. Measuring the resistance on the ICV will tell you pretty quickly. It's hard to get to that pigtail but it is possible.

JerryLook · 03-03-2021, 10:52 AM

Inside of the lift pump motor. With the new gasket (installed) versus old. The old one looks like a lot better quality. It might go back on. Haha

Where is the pigtail for the ICV? The valve itself is in the caps pump right?

The thing I keep getting hung up on is that I can’t bleed the system up to the caps pump. I can open the bleeder banjo on top of the caps, and run the lift pump until I get fuel out. I tighten the bolt after fuel starts coming out, but while the pump is still running. When I run the lift pump again fuel has already run back from the caps pump, and it has to be primed again.

Also, silly me. I didn’t fill the lift pump with fuel before reinstalling it. Now I can’t get it to prime at all. I’ll probably have to take the lift pump motor back off and fill it with fuel.

Fffrank · 03-03-2021, 01:06 PM

Here's what the ICV and it's pigtail looks like. The lift pump is self priming, btw.

Pull off the line from the second filter to the CAPS and see if you get good flow with the lift pump engaged.

https://www.tamerx.com/injection-pum...1998-2002.html

vito.a · 03-03-2021, 01:26 PM

It sounds like an air leak somewhere in the line, or in the pump.
Are the slides on the pump rotor free to slide?
I like to refill the pump and filters with Lucas fuel treatment. It cleans and conditions all the fuel system parts.

JerryLook · 03-03-2021, 01:31 PM

Ok thanks. I’ll look for the ICV in the morning when I dive into it again.

When I pull the line off the second filter I get some flow after about 20-30 seconds.

Now that I changed the lift pump gasket I have no prime. I think maybe that gasket doesn’t work well with my lift pump.

JerryLook · 03-03-2021, 01:48 PM

Vito-
The pump seems to spin freely and the vanes slide in and out like they should. I’m kind of surprised it didn’t prime itself when I put it back in. It could just be the gasket I got is not compatible. I bought it off of eBay.

Mile Marker 42 · 03-03-2021, 01:57 PM

Quote:

Originally Posted by JerryLook

Vito-
The pump seems to spin freely and the vanes slide in and out like they should. I’m kind of surprised it didn’t prime itself when I put it back in. It could just be the gasket I got is not compatible. I bought it off of eBay.

Was it the guy in Texas you got it from on ebay? if so, he sells 2 different versions.

JerryLook · 03-03-2021, 02:27 PM

Quote:

Originally Posted by Mile Marker 42

Was it the guy in Texas you got it from on ebay? if so, he sells 2 different versions.

Yes it was the guy in Texas. I contacted him and he told me they two versions were based on the ESN. I got the one that’s supposed to fit my engine. With that being said, I think my lift pump has been replaced before. And it’s probably aftermarket. So maybe the gasket won’t work with that one.

It just seems like the gasket isn’t thick enough to compress and seal. I’ll pop the old one back on tomorrow and see if it primes again. Then I’ll check that ICV.