BUZZING In Engine Compartment-NO START
 

I started my 1982 911 SC it ran rough for about 50 feet and then died. I tried to start it again with no luck. I noticed that the fuel pump was silent so I went into the fuse compartment and started looking around. I noticed that the red one (#7) was loose, so I made sure that the 30 and 87 were connecting and the fuel pump started pumping again! I felt like Dr. Frankenstein! Now I have a REALLY LOUD BUZZING coming from the engine compartment when the key is in the ON position. I tried to start the engine, but it will not fire. I pushed up on the flap behind the air filter, as this usually makes a screech, but I can't hear anything over the buzzing. I made sure the distributor was dry and tight. I even scratched off some carbon that had built up. I have a quarter tank of gas and a battery that is only a few months old. Any ideas why the engine wont fire?

Thanks!

The fuel pump doesn't run, unless there is airflow. The bussing is from your frequency valve and is normal. You can check if the fuel pump is functioning by taking off the air filter, turning on the ignition and lifting the metal disc for the metering unit. The fuel pump should run when you have the disc lifted.

Regards,

Jerry

Hey Jerry!
Thanks for your post! I am scratching my head!!!
I did just that, I took off the air filter and pushed up on the metal disc while my buddy turned on the ignition. Nothing.
I got the fuel pump working, but the engine will not fire now.

DAN

82 911 SC (ROT ELF)
02 Carrera (AG GEIST)

Do you have spark?
Easy way to test, if you have a timing light simply hook it up as instructed, then turn over the engine and does the light flash?


Jay

Frequency valves are normally not that noisy. The FV is located behind the throttle body area, behind the air box, along a fuel line. Touch it, and you will probably know whether this is your buzzing. Indeed, if the buzzing is that loud, then you should be able to find it. By feeling, or by using a piece of hose. Hold one end on your ear, and.........

With the key on, if you life the airflow sensor plate, the injectors should scream. If not, that's your starting problem. Spark has nothing to do with it. If those injectors are not screaming with the key on and the sensor plate pushed up, then I'd send you back to the electrical circuit that runs the fuel pump.

OK, while the key was on I pushed up on the sensor plate and get nothing.
I also noticed that the "red plug" #7 in my fuse area is really old. Could it be that simple? I swapped that one out with the black "horn plug" but get the same NOTHING.
Any other ideas?

THANK YOU!!!