Fuel Pump Pressure
 

:eek:My 02 S80,T6 had a fuel starvation problem which I was not aware of until yesterday...Twice when I clocked between 325 and 375 miles, with approx. 150 miles to go before empty, the car just stops..This last time I was at a garage having the injecters cleaned with 337 miles driven since last fill up..After the drip system was complete, the throttle body was sprayed with engine at about
2000 RPM....It flooded as knew it would, but would not restart and keep running...Any pressure on the gas pedal caused the engine
to die....Ah, a light came on in the old head and a fuel pressure check was made..Reading was 15psi, which should be about 57psi.
The fuel pump with about 5 gallons left in the tank was now not submerged in fuel therefore getting hot and not pumping the correct pressure...This heat caused the pump to fail unless the fuel in the tank was above the 1/4 mark...Anyway glad it was under warranty otherwise near $600.00 to replace....I had no codes whatever except when engines die and it says only 'check engine', this actually telling you nothing that you don't already know....Thought this would be a HEADS UP for others that may encounter
similar problems...Without the correct fuel pressure you can easily have hesitation upon acceleration, misfire and as I had, complete stopage...Good Luck

RE: Fuel Pump Pressure
 

That's strange, my wife said that she was running low on fuel yesterday and the car began to act strangely upon accelaration. After she filled up, there was no longer any hesitation upon accelaration. The car never died, it just behaved out of the norm.

Is there any way to easily test the fuel pump pressure as you had? The car is running very well, and I have never seen any other issues or indicators of an issue being present. I'm not going to worry about it, but you did peak my curiosity.

RE: Fuel Pump Pressure
 

Go to your trustworthy mechanic, am sure they all have meters check fuel pressure..Should cost very little...Fact is, may be nothing
if a problem is found and you decide to let him repair....

RE: Fuel Pump Pressure
 

I just got off the phone with the dealership and asked them what they thought. They said I shouldn't worry and just keep an eye on it. Being as all symptoms went away after filling up, they said the fuel pump was not the likely cause, we'll just have to wait and see. I drove it around all day today and the car ran like a champ.

RE: Fuel Pump Pressure
 

Like I mentioned previously, if your good at full tank, then at or just below 1/4 tank the engine wants to die, its almost centain its
something to do with the fuel pump...I know on the S80 the tank straddles the exhaust pipe, (thats the reason for the hump in the back seat) and its almost like you have two tanks..This requires the main pump and an intank pump..The main pump is on the pass side of the tank and intank is on the drivers side..The intank pump feeds the intake of the high pressure pump when the fuel in gas tank
is on the bottom half..Rather confusing and trying to picture it w/o actually seeing the fuel pump and associated acessories that make up all the parts..I saw mine yesterday and the above was explained to me....I was also told when installing a new system, must be carefull in not bending the line that connects the two fuel systems...Hope this helps

RE: Fuel Pump Pressure
 

I will bet one sending unit is reading incorrect.
This will fool you into thinking you have more gas than you really do.

It is a common problem with these cars.

RE: Fuel Pump Pressure
 

:eek:Thanks for the input Tech....Am sure your correct, but I wonder how many of us actually almost empty there tanks prior to fill up..??This way you'd know if your readings are correct...In my case the hose was bent not allowing fuel flow to main pump, thus causing the pump to run, getting hot and eventually burn out.....I'd also bet it was the orginal pump installed at the factory and orginal owner always filled up at or above the 1/4 level....Glad I had the warranty...Have fun on your cruise...We took one of those for our 50th about 4 years ago...Fairly hot and very humid if your sailing from Florida..Lots of fun...

RE: Fuel Pump Pressure
 

Thanks I will have fun.
Yes we are sailing out of FLA. I live here so it is about 1 hour trip to the port.