AFM fuel pump shut off, not shutting off after adjusting

[JereandJess]

A few summers ago Colin stopped by and helped us get the FI running in our 78 blue bus.

I documented the troubleshooting process on the samba thread:

http://www.thesamba.com/vw/forum/viewtopic.php?t=118520

Check out page 2 for the solution when Colin was here with us.

I said in the post that we adjusted the black wheel to lean it out, and I recall Colin saying that we went something like 26 clicks, which was unheard of, but the tests told us to do it.

Is it possible that turning it so much affected the "springyness" of it and it just doesn't have enough left in it to spring back and shut off the pump?

As soon as I turn the key, the pump starts running, and it is my understanding that the idea was to have it cut off, so if there was an accident, the fuel pump shuts off for safety.

If I start tightening up the spring, it will be making it more rich. That is a problem because I think it's running too rich already.....

Any suggestions anyone?

[vwlover77]

Tightening the spring makes it more lean, not more rich. Your 26 clicks to the lean should have given it more power to open the switch contacts when shut off.

Have you verified by looking inside the cap of the AFM that the fuel pump switch is closed (contacts touching each other) with the engine off?

If that is the case, you may just need to bend the big silver wire that opens the contacts to adjust it.

If the contacts are already open, there are wiring issues somewhere.

[Gypsie]

Tightening (CLOCKWISE) the spring makes it more lean, not more rich. Your 26 clicks (CLOCKWISE?) to the lean should have given it more power to open the switch contacts when shut off.

Have you verified by looking inside the cap of the AFM that the fuel pump switch is closed (contacts touching each other) with the engine off?

If that is the case, you may just need to bend the big silver wire that opens the contacts to adjust it.

If the contacts are already open, there are wiring issues somewhere.

in the picture below, the AFM fuel pump contact was shutting off at #36 & 37. The pump contact was touching the sweeper counterweight. We bent it a little and adjusted the mixture and off we went! .

You probly bent it a bit out of the way of the boom. As suggested bend the 'disconnect boom' (clockwise) on the sweeper unit and you should be back in business.