How do I interpret this??

[keithbkeller]

Hi Everyone!

I have a cold start problem with my 81 911 SC. It sputters and dies out. Now here's the information that makes this so confusing. First, It is only pumping 6 oz of fuel in 30 seconds from the fuel distributor into a container with a battery charger hooked up front to the battery. Second the WUR shows no change in pressure when the electrical plug from the WUR is plugged in for 5 minutes or unplugged. I am getting 24 psi tester valve open and 70psi closed, cold pressure. Finally, my plunger in the fuel distributor has dropped down and on top of that when I reach around behind the fuel distributor to feel if the frequency valve is vibrating I feel nothing going on. Could all these things be systematic of one thing such as a bad fuel pump?? Please help!!!

[yelcab1]

What is the system pressure?
What is the cold control pressure?

[boyt911sc]

Originally Posted by keithbkeller

Hi Everyone!

I have a cold start problem with my 81 911 SC. It sputters and dies out. Now here's the information that makes this so confusing. First, It is only pumping 6 oz of fuel in 30 seconds from the fuel distributor into a container with a battery charger hooked up front to the battery. Second the WUR shows no change in pressure when the electrical plug from the WUR is plugged in for 5 minutes or unplugged. I am getting 24 psi tester valve open and 70psi closed, cold pressure. Finally, my plunger in the fuel distributor has dropped down and on top of that when I reach around behind the fuel distributor to feel if the frequency valve is vibrating I feel nothing going on. Could all these things be systematic of one thing such as a bad fuel pump?? Please help!!!

Keith,

Which of the seven (7) fuel injector lines are you getting the 6 oz fuel per 30 sec.? If you are getting 24 psi. cold control and 70 psi. system pressures, the FP is running. To test the FP, you need to determine the flow rate and its max. delivery pressure. Less than 80 psi. is on the low side required for CIS and healthy FP could deliver 90+ psi. and up. Keep us posted.

Tony

[keithbkeller]

The first time I did the cold test I was getting 70psi with the valve closed to the wur and with the fuel coming in from the center line of the fuel distributor to the pressure gauge. Now all I can get it 30psi?? And this is with a battery charger running to pump up the voltage.

[boyt911sc]

Originally Posted by keithbkeller

The first time I did the cold test I was getting 70psi with the valve closed to the wur and with the fuel coming in from the center line of the fuel distributor to the pressure gauge. Now all I can get it 30psi?? And this is with a battery charger running to pump up the voltage.

Keith,

The battery might not be fully charged when you did the last test. Have the battery charged and retains 12.40+ volts (min. 12 v) and do the FP test again. If your battery is old and weak, it might not hold power long enough to maintain load.

Why are you checking and measuring the flow of fuel to the WUR? What are you going to do with the data you got from doing this test? What's your objective? Keep us posted.

Tony