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Discussion Starter · #1 ·
Occasionally my ZXT fuel pump stops, I jiggle the fuel pump control module(FPCM) around, then I get back the 5 second prime on the fuel pump, starts and runs fine. Did that today and now she is running like a champ.
More power, tach to 5.5k real fast, boost all the way!
Question 1 Am I missing a ground on the FPCM?
Question 2 Can I just disconnect it? I have read yes and no in a search.
 

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I studied the diagram a while back. It looks like you can bypass it at the FPCM connection. YR wire if my memory is not being foggy. Rust under your windsheild?
 

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Discussion Starter · #3 ·
fpcm

Hay thanks. No, no rust, not there, just behind the seats.....
So to disconnect I jump the YR over?
She is running great, like the Volts to the pump was low, now it is like a ZXT again!
 

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No need to bypass - just disconnect it. 1982 280ZX Factory Service Manual - Section EFEC, pages 75 & 76 describe it's operation and purpose. It connects to the power suppy wire of the fuel pump and either has no effect (full voltage to pump) OR under certain conditions "... the fuel pump operation is controlled in order to reduce fuel pump noise and the power consumption of the fuel pump." Under certain conditions, the FPCM reduces the voltage to 9.8V. When the FPCM is unplugged, the fuel pump runs at full voltage and is still controlled on and off by the ECU. (I have a 1983 280ZXT in the shop right now with the FPCM disconnected - nothing is affected except the fuel pump never sees reduced voltage...)
 

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Discussion Starter · #5 ·
Thanks for the input, I did unplug the unit and did not here the pump, then again I did not turn the key to start? Taking it step by step. I need to look at the diagram, I do not understand how it can be unplugged and run? She is running so great at times, taching up, yummm. The FPCM felt quite warm?
Thanks
J
 

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fpcm

Hay thanks. No, no rust, not there, just behind the seats.....
So to disconnect I jump the YR over?
She is running great, like the Volts to the pump was low, now it is like a ZXT again!
If you disconnect the FPCM, you will disable the fuel pump. Perhaps there is another way to bypass the FPCM.
 
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