Fuel Pump amperage
- Harrison3267
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Sooo heres what I got. 2006 Ford F-250 5.4L with a P0191 code only.
Customer Complaint lacks power on up hill pull.
Checked fuel pressure with scan tool and fuel pressure dropped to 6 psi on a high throttle run and I wish I had gotten a picture of that.
But what I do have is pictures of the amp wave forms of the fuel pump start up and the fuel pump running.
What I dont know is how good these look. I see some issues but am I seeing things?
So for those in the know and are use to looking at these wave forms and calling pumps any advice?
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- juergen.scholl
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The pump current wave forms looks fine, a bit on the high side. ...... might be a resttriction like bad filter, but not very likely.
What do the O2 show on WOT acceleration?
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- GeekDIYMechanic
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The O2 and fuel trims can tell you a great deal about fuel delivery as well. How do they look at idle, 2400, and at a snap throttle?
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- bruce.oliver
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This is a PWM pump controlled by the fuel pump driver module. Tap into the power and ground at the pump, between the pump and driver module. At idle your DVOM should show 7-8 volts. And as the demand for more fuel increases the voltage will rise on the volt meter. Put a fuel pressure gauge in line to verify the pressure sensor is working. The gauge and scantool will be different unless you unplug the vacuum hose from the sensor, then the readings will be roughly be the same. Last one I did the voltage on my meter was almost battery voltage at idle so the fuel pressure had no where to go but down under a load. It needed a pump
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- juergen.scholl
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bruce.oliver wrote: This is a PWM pump controlled by the fuel pump driver module. Tap into the power and ground at the pump, between the pump and driver module. At idle your DVOM should show 7-8 volts. And as the demand for more fuel increases the voltage will rise on the volt meter.
Does this have anything to do with the, slightly, higher amp draw? I have often wondered what the effects of a PWM pump would be on the current waveform. I have not taken the time to play. And, have not had a NEED to, yet.
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- bruce.oliver
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