Fuel Pressure q's

[toms89]

Depending on the gauge it may need the schrader valve removed. If you had no fuel pressure she would not run.

 

[Edwindo]

When you say it may need the schrader valve removed, what do you mean? On the gauge itself or are you talking on the fuel rail?

 

[toms89]

When you say it may need the schrader valve removed, what do you mean? On the gauge itself or are you talking on the fuel rail?

The fuel rail.... Unless the gauge you are using is set up to fully depress schrader valve you will not get an accurate reading.

Any aftermarket fuel pressure gauges you would permanently install you remove the schrader valve.

Do not attempt this unless you can guarantee a good seal where the gauge screws on to the rail or you may have fuel spraying everywhere.

 

[Edwindo]

I've checked the fittings. The gauge I have is set up with the large threaded end on the hose, and then an adapter to go on the smaller (schrader) fitting. I have done several combinations of things, including screwing on just the small fitting onto the valve on the rail, and depressing the valve. A little trickle comes out, and I have checked the adapter in the gauge and it does seem to fit correctly and actuate the little pin in there.

It's still confusing to me that when I depress the pin in the valve on the fuel rail, I'm not getting a spray of fuel coming out of it with the system pressurized.

 

[toms89]

I've checked the fittings. The gauge I have is set up with the large threaded end on the hose, and then an adapter to go on the smaller (schrader) fitting. I have done several combinations of things, including screwing on just the small fitting onto the valve on the rail, and depressing the valve. A little trickle comes out, and I have checked the adapter in the gauge and it does seem to fit correctly and actuate the little pin in there.

It's still confusing to me that when I depress the pin in the valve on the fuel rail, I'm not getting a spray of fuel coming out of it with the system pressurized.

Depress schrader valve on fuel rail as she is running....it should come out under high pressure. If its not running as K5rnt said you may have no pressure if it bleeds down as the pump only runs 2-3 seconds on initial key on position.

 

[Edwindo]

Ok, will do. Thanks for all the help guys, I gotta run now and get kids to their stuff in a bit. Never a dull moment!

 

[K5rnt]

There are only so many parts in the fuel system. It basically has to be the pump, filter, regulator, or maybe an injector. I'm betting on filter or pump. Of course I have been wrong before lol

 

[Edwindo]

Ok, finally got my pump pressure tested. Turned out the adapter on the gauge that I was using didn't fit right, got that switched and hey presto, the gauge worked.

So, what we found was that the key on really didn't even register anything on the gauge, which is a little suspect, (just confirms that the pump check valve is bad) but once the engine was running, it showed 45 psi. When we hit the button to do the flow test, it only dropped about 1 pound, but we got air bubbles. Lots of very even, consistent bubbles in the output. My tank was 3/4 full, so somewhere its pulling air into the system.

Anyone have any thoughts on the situation? Is it just time for a new pump, or is there something on the return side that I should look for to find a leak?

Thanks again!

 

[K5rnt]

I say change the pump. I don't think there is anything on the return side that could cause you to loose pressure. The way I tested my check valve was I took the fuel filter off and blew on the line going back toward the pump. Since I could blow into it and hear bubbles in the tank it was pretty easy to figure out that was where my leak was.