Fuel Line Pressure And Pump Check Valve Issues

[Captain Obvious]

Haha! How about you send me your old one so I can see what I can do with it? If I can fix one, I should be able to fix two of them!

I'm like this close to making a new one from scratch... :pirate:

[Captain Obvious]

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.

Forgot to address the 1587010532 valve... This valve is not a good choice for our application. Not specifically because it's threaded on both ends, but more so because it's designed to be used with a banjo fitting on the outlet side. Think "banjo connector onto the fuel rail".

There are other check valves that are threaded on both ends that would be better choices because they are simple pass throughs. You could either screw a conversion fitting onto the outlet to convert to hose, or you could turn the outlet threads smooth on a lathe and clamp a hose where the threads used to be.

All that said, I'm still thinking that a stand alone in-line valve up in the engine compartment would be a better idea. Not only for future serviceability, but because you could put it downstream of the filter. From what I've read in search, it's usually dirt from the tank that contaminates the original valve's seat and stops if from sealing.

So why don't I jump on the generic Airtex valve that was suggested above? Because it's got too many leakable joints. I want something that's native hose and clamp connection. Something like this one mentioned in this thread on an RX7 forum:

(FUEL) How To: Diagnose your fuel return line check valve - RX7Club.com

[Zed Head]

That RX-7 valve does look nice. I Googled fuel line check valves and found a similar one - Fuel line check valves. Right direction?? - Alfa Romeo Bulletin Board & Forums

Here's one that even has the barb size, although they're the one way type. http://www.ebay.com/itm/One-Way-Fuel-Valve-5-16-8mm-SVO-WVO-Biodiesel-Diesel-Fuel-Line-Check-Valve-/181080394722

Can't stop - http://www.ecstuning.com/Volkswagen-Corrado--VR6_12v/ES292046/

And if you could find this one in the right size-metric, you'd be golden - http://greatlakesskipper.com/en_us/standard-1-2-inch-boat-brass-fuel-hose-fitting-w-check-valve

Finally, from boats to tractors - http://www.koopvanderwalparts.com/check-valve-fuel-line-john-deere.html

Edited June 5, 2013 by Zed Head

[Captain Obvious]

Haha! The results of your searching look very similar to the results of my searching!

I don't like the barbs, but could get over it if that's all I can find. I could turn all the barbs off except the two at the tips, or I'm sure I could just use it as is if I'm not that energetic. Hadn't seen the one from the Alfa before. Looks as good as the Mazda, but I bet the case is made from unobtainium.

I went to the local parts store and talked to them about Mazda check valves, and they couldn't find anything. Also couldn't find anything on Rock Auto. I'm trying to avoid joining that forum just to ask questions about valves.

There was one more that I turned up that had hose nipples on both ends and a mounting tang with a single screw hole in it that was used to screw it to the fender well. I'll see if I can find that one again...

[Captain Obvious]

Here's the flanged one I was talking about. Here's an example on Amazon:

NEW OEM MAZDA FUEL TANK CHECK VALVE : Amazon.com : Automotive

Looks great, but at $56, it's pricy:

[Wade Nelson]

Here's a picture of that first ebay valve. $14 + S&H Looks like a winner to me!

[Captain Obvious]

Yeah, that's probably what I'll do to start. Get one of those and turn the barbs off.

It'll either be that, or something from McMaster. They have brass bodied check valves with fluoroelastomer (Viton) seals for about the same price. They're likely higher quality than the ebay valves, but the only problem is that they are all NPT on both ends, so I'm back to more fittings and adapters and joints that can leak.

If I had other stuff I needed from McMaster right now, it would be a no-brainer, but I don't think I need anything else from them at this time.

[Captain Obvious]

I've got a couple ebay check valves on order. Should be here soon, but in the meantime, I had another idea...

Anyone have leads on a car that used an electrically controlled SOLENOID VALVE on the fuel supply? Something that electrically blocks or allows the flow of fuel through it based on an electrical signal.

If something like that exists, I could easily wire that into the system such that it will only allow fuel flow when the engine needs it. I've seen devices like that used in the vapor recovery system, but I've not seen one used to actually control liquid flow.

So, anyone ever seen such a device used for gasoline control?

[siteunseen]

My Mercury outboard motor had a enrichner solenoid valve that let fuel threw when you pushed in the key on the control box.

Mercury Quicksilver 89-819503A2 Boat Solenoid Kit / Enricher Valve | Great Lakes Skipper

[Captain Obvious]

Thanks for the tip.

Solenoid valves are easy to find. Solenoid valves that are guaranteed to be compatible with gasoline (and ethanol) aren't so easy to find.

[rcb280z]

I have the one that Wade pictured and it doesn't hold pressure for me. Unless it's a problem with my FPR and it escapes me on how to check that.

[Captain Obvious]

Haha! Great... That's one of the ones that's on it's way to me! I bought one of those, and one of the Bosch units that's threaded on both ends thinking that I might be able to modify it to fit better. Sorry, but here's to hoping that your issue is somewhere else! :classic:

To test the check valve on the supply side, clamp the line from the fuel filter TO the fuel rail.

To test the FPR, clamp the return line FROM the fuel rail back to the tank. The OTHER line over by the fuel filter.

If you clamp them both at the same time and you still lose pressure, then you've got a leaking injector, cold start valve, or are leaking fuel through the FPR into the vacuum control line connected to your intake manifold.