Fuel pressure problem on a 2001

[bromark]

I have a 2001 2.2 5 speed. When you first crank it it stumbles and sputters with the rpm falling way low. I have replaced the fuel pump, fuel filter, crank position sensor, cam position sensor, and idle air valve. I have about 25 pounds of pressure when I turn the key on which falls instantly to 0. I have replaced the pump a total of 3 times trying to fix this and it changes nothing (Thankfully I have a good parts store that is willing to honor their warrenties so I only bought 1) I know the cat is not stopped up. The only code I am getting is 0179. My fear is that the only thing left is the flex fuel sensor. It cost about $650 so I would like to be sure before I go for it. any body got any suggestions or advice.

Mark

[old_master]

Your fuel pressure readings are very common results for a leaking check valve or flex tube in the fuel pump. Airtex pumps are known to have that problem... right out of the box. Here's how to check fuel pressure:

Make sure there are no visible external fuel leaks. Key ON, engine off and cold, fuel pump running, fuel pressure must be 41psi to 47psi. If pressure drops more than 5psi for 10 minutes after the pump shuts off, there is an internal fuel leak in one or more of the following: Fuel pump check valve, fuel pump flex tube, fuel injectors, or fuel pressure regulator. To check the fuel pump check valve and flex tube, a temporary shut off valve must be installed between the pump and the fuel rail. The valve isolates the pump immediately after it pressurizes the system. If pressure holds, the problem is in the tank.

[bromark]

Where is the best place to install the valve and what is the best type of valve to install and my fuel pressure never gets above 25.
Mark

[old_master]

Fuel pressure at 25psi with excessive leakdown is the problem, guaranteed!

This is what the valve assembly looks like:



The entire fuel system special tool kit can be purchased for around $400.
To diagnose your leakdown issue, this is the only special tool you will need. This valve assembly can be fabricated at home with a couple of wrenches and a screwdriver for around $25.00. The fuel injection rated fuel line and fittings are readily available at most auto parts stores. The valve can be purchased at any home improvement store or hardware store. It connects inline at the fuel filter.

[bromark]

Thanks for the information and the help. I am sure I can build the valve assembly with no problem with the picture to look at it will be easy. I think you are right about the problem I am just tired of changing pumps. I have done it 3 times since december and 2 times in the last month. I am also thinking of jumping the fuel pump relay to see if it will build any pressure if I let it run for more than a couple of seconds.
Mark

[bromark]

Old Master
Thanks so much for your help. I have found the problem and it is actually simple but AGGRAVATING! Sorry but I had to get that out. It is the pressure regulator that is built into the fuel filter. I blocked off the return on the filter and the fuel pressure went up and up. I then put the old filter back on from a the last change and it went straight to a little over 60 and held like a rock. Again thanks for you timely responses and help the idea about the valve is what made me think to try blocking off the return before I went any further.
Mark

[old_master]

Good job, glad you found the problem and got her going.