Problem with fuel reservoir check valve

[herbwag]

Guys,

My 1988 Ranger has the 2 fuel pumps system with the single-use fuel reservoir
(with no filter) between the pumps. The truck had not been starting or running
well and I traced the problem to the fuel reservoir. The reservoir bowl
o-ring leaks and the reservoir inlet check-valve is bad. The valve has
"jumped" its seat and rattles around loose up inside the reservoir top along
with the spring. I can pull it back down but it's too worn to stay in place.
If I blow air into the inlet nipple the valve sometimes blocks the fuel
inlet passage. I think the same thing happens with incoming fuel. That is,
the valve piece blocks the passage and starves the reservoir bowl and frame pump
of fuel and air gets sucked in through the leaky gasket. The engine runs
really crappy that way.

My question is this: How essential is the reservoir check-valve? If I remove
the broken check-valve from the reservoir and operate it like that, will the
fuel system still work if everything else is right? Isn't there another
check-valve in the tank-pump that serves the same purpose as the reservoir
check-valve? Has anyone tried running without the reservoir check-valve? If
so, what were the results?

New reservoirs are hard to find and expensive. The only one I found
online is $131.00 plus $4.99 shipping. Aftermarket units don't seem to be
available. Possibly I can find one in a junk-yard but there are no
junk-yards nearby. I'd like to just pull the check-valve piece and spring out and replace the bowl o-ring and try it like that. I may do it. But I'd like to hear you
guys' opinions and experience on the matter. Some of you must know this
goofy 2 fuel pump system and how it works way better than me.

I believe the part number for the single-use reservoir unit is:
FOTZ-9K044-A.

Thanks,
Herb W.

 

[tomw]

Check for my answer on fordrangerforum.com ... may not help... but ???
tom

 

[herbwag]

Check for my answer on fordrangerforum.com ... may not help... but ???
tom

Thanks Tomw. Anything to better understand and fix this Ranger is a big help.

 

[herbwag]

Running OK without reservoir check-valve

Update: 1988 Ranger fixed. See Post #1 for original problem/question.

As mentioned, I proceeded to remove the check-valve from the plastic fuel reservoir (Part #FOTZ-9K044-A). I just broke off the worn valve head with a needle-nose and left the stem and spring in place. Put a new o-ring in the reservoir bowl and re-assembled. Cleaned fuel line nipples and lightly oiled them. Then installed reservoir unit back into truck and reconnected fuel lines with used hairpin clips (I have new ones). Leaving the reservoir unbolted until last makes it easier to attach lines and clips.

When it was back together I tried key "on" 4 times. Fuel psi only went up to 3-4 psi. (Remember: fuel reservoir was empty at this point). Jumpered fuel pumps off test connection: within 10 seconds fuel pressure up to 39 psi (previously this took 1-2 minutes).

Started engine--three short tries--then it caught. Instantly seemed to run PERFECT. Fuel pressure dropped to 32 psi and held steady. (Previously the fuel pressure went up and down until motor stalled). Now it idled nice without any throttle when cold. Did NOT stall or idle rough at all. Ran smoothly. No visible gas leak or smell around reservoir under truck.

Let truck sit for 2 days. Fuel pressure dropped to 20 psi and held there. Turned key to "on" one time and pressure went up to 39 psi. Started engine on second short crank. Fast idle 1500 rpm. Dropped to 1200 rpm. Blipped gas. Seems to operate okay. Put into gear. No stalling or hesitation or loss of power as previously. Seemed normal. Took down road a mile and then back. Idle 1050 rpm. Took down road and back a second time. Seems fine. Running perfectly it seems. Next day psi down to 20 psi. "On" right up to 39 psi. Starts good.

I think this truck is finally fixed after 2 years of replacing various parts-- both fuel pumps and some ignition parts. The problem was a worn-out check valve in the fuel reservoir that blocked entry of gas. (Possibly front fuel pump was also shot--rear one probably good.)

In conclusion, taking out the check-valve does NOT seem to affect anything important--although it must be there for some reason. When replacement fuel reservoirs become available again, I may or may not replace mine. For the time being I'll run the thing as is. It's mainly a wood hauling work truck around my place in the woods.

Learn from my experience and if your truck starts poorly (will only start with Starting Fluid and then runs like crap, no power, stalls, etc.), do a fuel pressure test RIGHT AWAY. I would have done it sooner, but Ford buried the Schrader valve so deep and hidden I couldn't find it. But when I did putting the tester on wasn't that bad. Also, look at the blue translucent fuel lines with the pumps running. I was able to see air bubbles in mine. That told me something in that area was amiss once I knew the fuel pressure wasn't right.

Coming from carburetor vehicles, I didn't know how critical how fuel pressure is with EFI. Now I get it. Also a book on fuel injection and engine management is useful to learn how the system works. I have the Probst book and it's good. That's what finally clued me in. Hopefully the truck really is fixed. I think so.

 

[Mark_88]

I was tryng to help another member with a running problem (starts OK) and this came to mind but I wasn't sure about it because I've never had a vehicle with this system (I did but removed it and went carburetor)...

This is good to know and if you have time...make a how-to step by step or whatever if you can...since it is still fresh in your mind...pictures always help but not necessarily of the step by step process...

The rewards are limited but someone, some day might find it and say "Aha"...and thank you for taking the time...