I have a question to the video "Symptoms and Causes of Low Fuel Pressure (Part 1)", despite knowing that there exists a voltage drop on the power lead, why the pump just replaced or did you also corrected this voltage drop mentioned in the video which I may passed.
I ask this just to understand and learn from your great instructions, would this voltage drop effect the new pump on the mid/long term.
Oeztuerk wrote: despite knowing that there exists a voltage drop on the power lead
The power feed on this car does not have a voltage drop. Minute Marker 54:55 shows 11.71volts, which is battery voltage. The voltage is low because the key has been on and the fuel pump running for some time with out the engine running to keep the battery charged.
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Hello Pole,
Thanks for your explanation, have just one question, what would happen actually if pump Runs with voltage drop on one of the leads, plus or minus and Maybe both. Will it demage it, why it is so important, is there any limits for voltage drop on the leads.
There will always be some voltage drop it can be tiny or it can be large it depends on the condition of the wires and connectors and most usually the grounds.
Fuel pumps and every electrical item on a car are designed to work over a fairly wide voltage range, a pump motor has to work from about 9v or less during cranking to at least 15v so should have no problem operating at say 11v although the output pressure and flow rate will be lower than a 14v it would normally still meet the demands of the engine.
As long as the pump is spinning low voltage will not damage a pump the most likely issue would be poor cold starting.
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In 11 years worked as a roadside technician (left that job now) I had twice manged to get a "weak" fuel pump to continue running after starting using external fuel; such as carburetor cleaner thru the inlet manifold. On the road side this will help the customer to drive straight away to his garage/mechanic and of course taping on the fuel tank to get a better temporary brushes contact might achieve the same result. This is why some mechanics try to push start (A manual gear type) bypassing the starter motor and save needed energy to the fuel pump and ignition.
