Help me interprit my new Fuel Pressure tester readings

[valsound]

I bought at sears a new fuel pressure tester kit (actron $39.00)

I am using it to troubleshoot my 1986 2.9 4x4 manual Ranger.
Instructions say to install brass ford adapter fitting & Hose fitting finger tight on to the schrader valve.

I did so, positioned it so I could see gauge through the windshield, & when I started the truck my gauge needle didn't move off of zero.

Great! I thought... faulty new tool... or what could I be doing wrong?
Maybe overtightened? Perhaps the rubber o-rings got too mushed & restricted the valve or fuel flow.

So I reattached the fittings more loosely. Now when I started the truck, the needle moved up to say 20psi. I pressed the black purge button & only a little gas came out.

I once again disconnected & reconnected the fitting & hose.

This time the needle jumped up to 42 psi at ignition key to run, & when I started the truck pressure came down to 34 psi at idle.

Question #1 Was all that not able to get it to work just having to prime the black hose with gas? Nothing in the instructions said anything about that.

Here's how the truck behaved after this point: I turn ign. key to run, the fuel pressure flies up to 44psi. pump quits & pressure relaxes to 42psi & holds there steady (as long as a minute)

I start the truck & pressure drops down to 34psi. It holds pretty steady as it idles.

If I rev the motor, the pressure jumps up to 42, back to 32 then 34 at idle.

When I shut the motor off, the pressure goes back to 40psi.

Question #2 Are my readings within spec? & are the fuel pump & pressure regulator happy? (I've been doing a lot of reading on this site the last couple of days & following links & I think my readings seem ok?)

Question #3 Did I do something wrong at first with the new tool? Or do you always have to prime the hose before you take a reading.

As always, Thanks!

 

[kevcov]

i dont know what the problem was at the start but it sounds like all should be good with it. but off the top of my head i dont remember what the psi should be at but as u turn the key it primes and onve the psi reg gets vac from the engine than it drops the psi to spec which i think is around 30 than u turn it off it shuts off the injectors and kills the engine so it should be good but i can look at what the spec is for the psi in the morning..... but i have to say its 3 in the morning and im tired so u may want to wait for some more people to put there 2cents in. however what is happening to make u check your fuel pressure?

 

[valsound]

For weeks I have had an itermittant crank with spark but no start.

Starting fluid in the intake will make it want to fire.

Checking fuel pressure at the schrader valve was suggested as something to rule out.

So I bought the tester & was using it for the first time.

Next time it acts up & doesn't start, I'll do the test again.

Just trying to rule stuff out.