Fuel Line Pressure And Pump Check Valve Issues

[Captain Obvious]

Thanks Zed for the info. Your note about the supply line to the pump "will do more than drip when disconnected" is just the kind of thing I was looking out for. Thanks for that. It's stuff like that which I want to be prepared for.

My pump is fine, it's just the check valve that's not working. I diagnosed that it's the check valve by clamping off the supply line between the filter and with a helper, killed the motor at the same instant. This left the rail pressurized, but shut off both the supply and the demand. With that line clamped shut, the rail held pressure, for some time at least.

It was down in a few hours, but with the supply line from the pump open, my pressure falls off almost instantly. In other words... My FPR may be slowly leaking as well, but big fish first. :bulb:

[siteunseen]

It's definitely an M10, I've got a cheap plastic nut & bolt gauge, and it's definitely not a 1.25 thread or 1.5, I've got a tap & die set and it won't screw into either of those 2. I do not have a bolt that will screw into it, neither will the 1.25 & 1.5 taps. It has 5 threads per 5mm or 2 10ths of an inch the best I can tell so as usual your right! It does have a copper washer between the valve and the pump body.

Edited June 3, 2013 by siteunseen

[siteunseen]

If there's an easy to remove M10x1.0 bolt on my car tell me where and I'll check it out for sure but I think you've nailed it down.

[Wade Nelson]

In less than 30 minutes you can run to NAPA, buy the Echlin check valve I describe, cut your fuel line in half in the engine bay, splice it in, and crank down on two 3/8" fuel line clamps. Why even screw around with taking off the old pump, removing THAT check valve, attempting to match it, spilling fuel etc? What are you going to do when it strips, or leaks, not to mention working on your back with dirt getting in your eyes pulling that pump down!

Do you have some strange masochistic need to make this repair waay more difficult than it needs to be?

[Zed Head]

In less than 30 minutes you can run to NAPA, buy the Echlin check valve I describe, !

That part number in your other thread still comes up as a relay, not a check valve. Which NAPA and Echlin part numbers did you have confused?

[Wade Nelson]

Ok here's the correct part #s. Search on it at NAPA.com And you'll need two hose barbs as well, some teflon tape...

AFP CV8000 check valve

90-544 hose barb fittings. (1/4" barb for 5/16" fuel injection hose

3/8" fuel line clamps (2)

I remember buying a relay that day, obviously I got the boxes mixed up...

Oh, btw, here's (apparently) a Idle Air Control valve from NAPA for "only" $83 Rock Auto wants $92...

CRB 2797 ..... listed in the WRONG category!

And one more thing. NAPA has a screw-in check valve for a Bosch pump...

ATM 1587010532 but it's threaded on both ends, don't think this is right one for you...

Edited June 3, 2013 by Wade Nelson

[siteunseen]

Do you have some strange masochistic need to make this repair waay more difficult than it needs to be?

He doesn't want to burn down his garage. http://www.classiczcars.com/forums/open-discussion-280zx/49539-fire-z.html

[Zed Head]

Thanks for the part number. I might try one if I ever put my Aeromotive FPR back on.

Napaonline doesn't want to tell me which store has it available and doesn't sell it online so I searched a little more and found that CV8000 is the key part number and it's available at a lot of different places, like Autozone, Summit and Amazon.

It's Airtex brand, the guys who make fuel pumps.

[Captain Obvious]

Do you have some strange masochistic need to make this repair waay more difficult than it needs to be?

Ummmm... Have you not seen my body of work?

Thanks for the part numbers. I've seen lots of product offerings that have threads on both ends. I could easily turn off the threads on one end and set it up for tubing instead., but I would have to know what the threads are that go into the pump (and that's one of the reasons for my thread investigation above).

Napaonline doesn't want to tell me which store has it available and doesn't sell it online.

Yeah, Napaonline is no fun. I don't like their website either.

[Wade Nelson]

For pinching off fuel lines I saw (and copied) the perfect tool.

Buy a couple pairs of SMALL needle-nosed Vise grips. Put clear fuel hose over the jaws. (regular rubber hose would work fine too...)

Now you can pinch off a fuel line in seconds without damaging it and leave it pinched off as long as you need.

[Captain Obvious]

Neat idea about the tubing over the jaws to protect the hose you are pinching. I used the same needle-nosed Vice Grips, but without the protective sheath.

It worked, but it left a "soft spot" in the hose where it is now easier to squeeze than it used to be. Not really a problem though, because it's between the filter and the rail, and I'll be replacing that piece after I spend 100 fruitless hours messing with the check valve back at the tank and finally give up. You know... After I've spilled gas everywhere, got dirt in my eyes, and almost burned the garage to the ground. :paranoid:

[FastWoman]

Captain, I saved my original check valve, in hopes that you (I somehow knew it would be you) would come along later and figure out how to refurbish it. I'll keep hanging on to it.

I see no reason why the inline check valve wouldn't work just as well as the one on the pump. You can always pull it back off later, once you've figured out the refurb process for our old ones.

As a compromise fix, I wonder whether the check valve Wade sourced (NAPA ATM 1587010532) can be fitted with a nipple on the other end.