fuel pressure?

[crashmy911]

tested my fuel pressure out of front of fuel distributor with a gauge and only get 40lbs pressure. this was done with engine not running and a jumper thru the fuse box. replaced fuel pump with new fuel pump still get 40lbs pressure. When draining gas tank I did it out of the line right before the fuel pump and it seemed like the gas came out of it fast enough so I have eliminated the tank as the problem. I was told it could be the fuel distributor check valve stuck in the bypass position on the side of the distributor. Is this something I can mess with my self or should I let some one else do it?

[vash]

was the car cold or warm? and your checking the pressure at the line going to the top and center of FD?

[crashmy911]

car is completly cold and the pressure should be I think 65 to 70lbs. So it is way off.

[vash]

if you are checking cold pressure (line between fuel dist and WUR) from the top of my head, i seem to remember 1.5bar. about 22 psi. and that is ambient temp. dependent. as the car warms up, the pressure increases to, ( i cant remember). i may be wrong, i am at work so i dont have any books with me. but i think i am right.

cliff

[crashmy911]

I'm testing the pressure with car off. The test says you should get 65 to 75lbs of pressure. Car isn't running. I'm only getting 40lbs which is way off. Any way what should the pressures be with the car running and cold and what should they be when the car is warm? thanks for the help.

[1981Targa]

Need the year of your car

First check Fuel Delivery - 70's up to 77 you should have 850 cm3 / 30 secs, 78 - Early 80's 1000 cm3 / 30 secs

System pressure 4.5 - 5.2 Bar
Control Pressure Cold is ambient temperature dependent

How do you have your guage set up...valve should be to WUR side

[crashmy911]

1978sc I'm checking both ways on with the car off and the gauge set up out of the fuel distributor cutting out the wur. this with a jumper so I don't have to have the car running and I will do it the other way with the car running and the guage set up from distributor to the wur. I Know the control pressure should be 65 to 75 when jumping the relay. This with the wur out of the equation. What should the pressures be when the car is running and cold and what should they be once the car is warmed up?

[1981Targa]

car does not need to be running to check - valve closed pump running only
basically to check cold unplug wur pump on, valve open however ambient temp needs to be known to give what value it should be
warmed up, wur vac hose disconnected should be 2.7 - 3.1 bar

[crashmy911]

temp is 34 F

[1981Targa]

too d##n cold...chart only goes to 10 C or 50F...in the Porsche Manual..if the line is followed it appears contro pressure "cold" would be 1.2 - 1.7 bar..not sure if that is valid though...
you must love this thing to work in that kind of cold..is that the temp of the garage your working in?
If you ran car with WUR plugged in measurement will be off for Cold Control Pressure

[crashmy911]

Yeah i'm nuts and have the flu!!!!!!!!!!