Fuel pressure, Schrader valve...

[xHeart]

This may be a good time to replace the fuel filter. There is a simple DIY on this topic, but little reference to releasing fuel pressure using Schrader valve before starting the task. Would someone please add to the DIY over there...www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=31420

thanks!

[jimmy57]

Most early 90's to present volvos with fuel filter outside the fuel tank will have the Schraeder valves on the fuel rail and one on the fuel line adjacent to fuel filter under the car. In some countries in Europe they have very strict regulation of spilled fuel so they had to put two valves and have an evacuation system to get fuel out of lines before filter is changed.
If you have a hose off an old bicycle pump use it with a pan and screw it on the schraeder valve by filter and let it run into pan.
Now go to schraeder valve on fuel rail and remove it or screw something on it to keep valve opened like another old bike pump hose. Now let the fuel drain 2-3 minutes then let valve close up top and then go under and remove hose and then change out filter. When you are through if the car is 99 or newer you will have a no return line fuel system and the air will be slow to get purged unless you bleed it.
Turn on ignition for 3 seconds 3 times, go to the valve on fuel rail and depress it and see if fuel comes out. If not, then repeat the key cycles and fuel check at fuel rail until you get fuel out of rail.

[jonl]

A few days have passed and I accepted that, at best, I have a weak fuel pump and after 16 years it needs to be replaced. The deed must be done!

So, I got up the courage and my dremmel and asked a good friend with more experience than I to cut a big access hole next to the fuel lines. Many thank yous to Reese and to all who have written about their experiences with this procedure, we couldn’t have done it without you.

I then replaced the old pump with a new Volvo unit and spliced/soldered the old wire harness to the new pump. I was so excited to test the wiring that I forgot to reconnect the fuel lines Well, the wiring seems solid, the pump is pumping and I only needed to clean up a little bit of fuel.

Now here’s the weird part: Initially, I got fuel to the rail but it would not start. There was about 20 psi of pressure and it was holding it. The engine was so close to turning over. It made all the right sounds but it just wasn’t happening. I checked the fuel at the rail’s Schrader valve and got fuel and air. Maybe an ounce of fuel came out but now I can’t get any fuel at the rail.

The next logical step was to try and bleed the air out of the system. I tried two methods:
1) Turning on ignition for 3 seconds 3 times and then checking the valve on the fuel rail to see if any fuel came out. Then repeated the key cycles and fuel rail checks until I got some fuel. No success.
2) Next I jumpered the fuel relay, pressed in the Schrader valve and let the pump run until it pushed all the air out and I saw fuel. I let it run for 5 minutes. Could hear the pump pushing air through the valve but no fuel. Just some residual moisture.

I know that there is fuel in the tank. I could see it when the old pump was removed and the fuel gauge shows 6 gallons.

I’m guessing that the new pump was originally moving some fuel that was left in the lines but is now only pumping air because it’s not currently immersed in any fuel. Seems unlikely. The pump is right side up but, hey, I can’t see into the fuel tank right now.

Anyone have any thoughts?

Thanks,

[jonl]

Rats! Put this in the wrong conversation. Sorry.