Audi Repair Questions? Ask a Mechanic for Answers ASAP
Welcome, I'm Chris (aka Moose) I prefer to work when others don't, I am here around lunch and after dinner till after midnight.working after noon till just after midnight.
Can you take a fuel pressure reading direct out of the pump or before the filter?
So far it sounds like there trash in your tank that has damaged the pump or there line is restricted with debris or the pump connections are corroded and there is not enough power and ground to get the pump up to full speed.
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With the key on, you should be getting full battery voltage to the pump and a ground with no resistance to the chassis. One the pump has pressurized the system the pump should shut off. The cranking voltage will be lower because the starter is pulling the battery down. The pressure directly out of the pump needs to be tested to see if this pump is bad.
You said you ran a wire direct from the battery to the pump but you said the new pump does not pump. This fuel pump is bad.
So your new pump now works, what pressure is it making when tested?
Glad you found it to be the wiring concern I mentioned.
Hello again Chris here,