QuestionMy fuel injected superbeetle convertible has an intermittent problem. It will crank, start and then stall. Sometimes the Fuel pump is found to be non-operating, an other times it may start and the car will run fine. The twin relays have been replaced. I don't think the fuel pump stays running after the car starts. Where should I look next?
AnswerHi Tom,
Easy way to check if your fuel pump is running when the car is started:
1) Remove your air filter
2) Place your finger into the square hole that goes into the Air Flow Meter (looks like a Waffle iron). You will feel a movable flap in there.
3) Turn the ignition to the 'on' position.
4) Now that you know where the flap is, push it open slightly with your finger. You should hear the fuel pump operate, as the flap activates it. If it doesn't turn on, you found the problem. It could be one of three things:
a) Faulty wiring to the 'waffle iron'
b) An air leak in that black boot it connects to.
c) Faulty 'waffle iron' aka Air Flow Meter.
The principle is kind of straight-forward:
When you are cranking the engine over, the starter is what operates the electric fuel pump.
When the engine kicks over and gets enough suction, it opens that flap you just pushed with your finger... the fuel pump is now operated by the flap/switch.
That double relay controls the hand-off from powering the fuel pump via the starter to powering it from the flap in the Air Flow Meter.
Pretty ingenious, huh?
Good Luck, let me know how you make out.
Ron
