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Audi fuel pump II?
The saga continues:
I have done all the checks, relay, ground wires, changed spark plugs.
I checked the fuel flow, I have fuel flow all the way to the fuel
distributor. I removed a injector connection from the distributor and
tried to start it, but no fuel came out of the distributor.
I then removed the distributor and found the plunger to be very stiff.
The air flow plate would have a hard time pushing the plunger.
When I completely removed the fuel distributor and all the fuel ran
out of it, the plunger was freed. It seemed the plunger was
'pressure locked'. I reconnected every thing and low and behold the
engine started. It was running fine, but the fuel pump was making
much more noise than it used too. The engine then died, ran for about
a minute. I didn't disconnect the fuel distributor again but I assume
the plunger had become 'pressure locked' again. Some how the fuel
after the plunger would get locked in and the air flow sensor would
be unable to push the plunger.
Then I checked the fuel pump once more. It obviously worked, but how?
Could it be that it had failed in a very high pressure mode???
Is this mechanically/electrically possible???
The specs for the pump say it should take 8.5 amp at 11.5v.
As my digi-meter only goes to 10amp I didn't want to connect it to
measure the amps. I measured the pump resistance instead.
It was about .9 ohms, that gives 12.8 amps at 11.5v .
I wonder how accurate this is? Does the internal resistance of a DC
motor change when it is working??
I know that it changes for a AC motors.
>From all of this I diagnose that the fuel pump failed,
over pressurising the fuel distributor.
Do people agree/disagree with this???
If this is the case, did the increased fuel pressure from the pump
break the fuel pressure regulator in the fuel distributor? The
distributor also contains pressure regulators for each injector.
I am not convinced that the fuel pressure regulators in the distributor
are broken as the engine 'seemed' to run 'ok' for a minute, before the
fuel build up in the distributor stopped the engine.
How likely is this?
Any and all help would be much appreciated.