SO, 2000 Expedition, if I take my fuel filter off, and turn the ignition on, fuel should squirt out of the supply line to the filter, correct? Also, does the 2000 Expedition have a Fuel Pressure Module on it?

Thanks

 

So, here is my issue. Fuel pressure at idle is 28 PSI and holds there until I rev it up. The fuel pressure slowly drops to around 10 at 4000 rpm. Bad fuel pump??

 

There are 3-4 different pumps for the 1997 - 2004 trucks and EXP.. Each has a slightly different pressure setting. 28 psi is not too far off. I have never checked at 4000 psi, but I would expect the pressure to drop off at that rpm..... There is no FP module. There is a regulator under the hood on the dash that will relief if the pressure gets to high.........

WHAT IS YOUR PROBLEM ?

 

Could be a weak pump. Could be a poor ground. Could be a restricted fuel filter.
Pull the fuel pressure regulator vacuum line and see if that changes the fuel pressure.

 

I haven't driven the truck in several years. It stays in my shop up on the rack. When I went to start it up, It wouldn't rev up and died at idle. I checked the fuel pressure and just for good measure replaced the fuel filter.

When I checked the pressure again, it held right at 28 PSI with the vac line on. It goes up to a little less than 40 PSI with the vac line off. Either way, If I hold it at high speed, 3000-4000 rpm, it will eventually drop to 0 and die.

A CEL came on also. Code was P-0452. I don't know if that would affect engine performance though. Still need to trouble shoot that issue.

BTW, this is a 2000 Expedition Eddie Bauer with 70,000 miles on it. I've had to replace the fuel pump 2x in 4 years with it just sitting in the shop.

 

There are a number of thing here to address.
The fuel pressure should be up near 35 psi at idle.
As the rpm is increased the pressure normally will rise about 5 to 8 psi under normal conditions.
The reason for the vacuum line on the regulator is to cut fuel pressure back at idle when higher pressure it is not needed and make idle control a bit easier.
Any pressure dropping As RPM rises is not proper and is a fault of some sort.
Reason is...... the fuel injectors are rated to flow their pounds per hour rating at 38 psi.
The PCM decides on how much fuel to allow based on pulse width applied at any given moment. If pressure drops, this changes the fuel metering for an illegal reason.
My suspicion is from a code you have, the tank Evap system 'may' be the cause of the pressure dropping.
The fuel pump is capable of nearly 90 psi delivery to the fuel rail where the regulator drops the pressure and provides enough volume and pressure so the whole fuel rail does not see pressure changes every time an injector opens for each cylinder.
The system is designed to minimize pressure pulsations at the injectors to maintain smooth idle and overall operation.
The only fuel control is by the pulse widths dictated by the logic decisions of the PCM as any given moment.
I would try your testing again with the gas tank cap off to see if a high vacuum is being drawn causing the pump to lose pressure trying to draw against a building vacuum in the tank.
If it makes no difference then the pump is suspect along with an Evap system fault.. Look at the code description.
Good luck.

 

I really appreciate your 'detailed' response. I do my own tuning on my 39 chevy with 97 LT/4 engine using TunerCats software. So I understand pulse widths etc. I'll try to remove the cap and see how it does. As I posted, I suspect that due to the vehicle sitting almost ALL the time, with me starting it every few weeks causes havoc with fuel system components due to the ethanol in the fuel. This will be the 3 pump in 5 years with the vehicle never leaving the shop.

I really need to sell it, but it holds some sentimental value.

 

OK, I replaced the fuel pump, fuel filter, FTPS, and purge valve. Truck runs better but still not right. I can't accelerate quickly from a stop or kick it while moving. If I punch it hard from a stop, the engine runs up to about 2700 and starts sputtering and trying to back down. If I lift my foot and accelerate gradually, no problem, I can run up to 75 mph. But if I try to kick it from there the engine just bogs but not die. It will eventually pick up but only if I take my foot off the accelerator. ALSO, NO CODES THROWN

Does this sound like clogged injectors? This truck sat for 7 years and I only started it occasionally. I'm sure that is what killed the fuel pump. The gas in the tank looked like crap. ANY THOUGHTS??

 

You may have to flush the fuel rails out and have the in injectors cleaned.
This is classic for a truck that has sat for long periods of time.
The gas has Ethanol and goes bad in as little as a couple months.
It causes corrosion and heavy gum deposits.
Especially troublesome in power equipment.
Anytime storage for long periods, Stabil should be added to the gas.
Good luck.

 

Thanks. Yeah, I had Stabil in the tank\, but with the fuel staying in the tank so long, who knows. Borrowing my friends OTC injector cleaning outfit and see if that works.

 

have you drained the old fuel and replaced ? I don't see that anywhere ?

 

Sorry, yeah, when I dropped the tank to replace the pump I drained the old fuel and cleaned the tank. Put new fuel in with a bottle of Techron fuel system cleaner.

 

If I were getting an ignition miss-fire e.g. coil, plugs, wires, it should throw a code, correct? Wonder why I'm getting no codes even though there has to be a lean condition at speed? Any thoughts?