Still having problems with so called vacuum leak

[2000StreetRod]

gray wire

I'm staying in downtown Greenville for a few days with my wife so I don't have my diagrams. But the IAT sensor signal wire is the gray one.

 

[Gadget X]

The fuel pressure regulator is a round "doohicky" about 2 inches across, and it should be physically attached to the fuel rail, I think on the front passenger side of the rails, if I remember correctly. It's "hidden" location makes it harder to tell if the vacuum line has popped off of it.

 

[koda2000]

The fuel pressure regulator is a round "doohicky" about 2 inches across, and it should be physically attached to the fuel rail, I think on the front passenger side of the rails, if I remember correctly. It's "hidden" location makes it harder to tell if the vacuum line has popped off of it.

at some point the FPR was moved to the fuel tank. I know that's where it is on the 2000's, I'm not sure about the 1999 models.

 

[Gadget X]

Ah, didn't think it was moved until the gen 3. Is there still a vacuum line going to it back there?

 

[2000StreetRod]

fuel pressure damper

The fuel pressure regulator on the fuel rail was replaced in 1999 with a fuel pressure damper when Ford switched to a returnless fuel system. It's between the firewall and the coilpack - just barely visible in the photo below.

However, the fuel pressure damper has a vacuum hose connected to it. See What's that on the fuel rail?

 

[Boozerbear]

Hmmm. I cannot locate an elbow under the battery. How is it routed? IE, where does it begin and end?

I'm not sure what it's called but there are 2 lines that hook up under the battery one line goes to the gas tank and the other goes to the engine I think it's called a fuel vapor line. I just bought a 96 as a project winter truck and found that the elbow that connects the line leading to the engine was broken making it idl and run bad. If you still cant find the leak try spraying starter fluid in spots till you hear the engine rev up.

 

[ExloringXLT]

Flashing CEL

Thanks everyone…I've checked all the suggestions made here this weekend and still NO LUCK. Streetrod: You are correct, on my model the FPR is located between the firewall and coil pack. No loose hoses however.

What’s bugging me is the flashing CEL. What else could this mean besides the motor missing or multiple misfire? Don’t get me wrong, I can hear it, and can feel the misfire just by putting my hand near the exhaust pipe. The motor is misfiring.

My question this time around is why does the truck still have normal power and performance on acceleration? I live near I80 in the mountains where the only way up the hill is floor it. It performs fine upon acceleration.

Yes, the idle is very rough, hesitates from a stop, but never stalls. The motor does sound like crap. The idle at stop is also high. Around 1,500.

Ooops 2 questions. I’m told don’t drive the truck with a flashing CEL because it may ruin the Cats which I have two of. The damn truck runs fine, it just sounds like crap because of the missing. Would any of you drive it in its current condition?

I just paid the registration,, SMOG not due to OCT/2015.

Still looking for problems for the engine sounding like crap. Some odd noise is coming out passenger side of the motor - can't tell if its intake or exhaust manifold.

There is also a very bad fuel odor - both inside and out of the vehicle. My mechanic says that's just because it's running rich. I don't necessarily believe that. The odor is too strong.

 

[Turdle]

99 fuel pressure regulator is in the tank. however, 99 up does have a vacuum "pulse dampner" on the fuel rails.