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Jim Grant's Tech Tips
'92 GMC Safari, Fuel Pump Eater
Q:
I have
a continuing problem with fuel pumps on a '92 GMC Safari. The first fuel
pump failed at about 80k. At that time, the fuel pump relay got very hot
and melted the plug leading to the relay. A new fuel pump, relay, and
wiring pigtail were installed. Since then, the fuel pump has failed about
once per year, or every 5k to 8k miles. One pump only lasted a week. I
am on my 5th pump. Each time, a GM pump is used. Why are these pumps failing
so often?
-
Ed B.
A:
There
are possibilities that come to mind. The first would be the fuel pressure.
Why? A failing fuel pressure regulator or pinched fuel return line can
cause the fuel pressure to be too high. Too high of a fuel pressure overworks
and overheats the pump, which can cause early fuel pump failure. This
condition also causes the amount of electrical energy needed to operate
the fuel pump to climb. This can result in a greater flow of electrical
current. The increased current flow can cause electrical connectors and
wiring to operate at a higher temperature. This can cause melting of connectors,
hot relays and fuel pump failure. I would suggest a fuel pressure test
but do not stop there. You should also have the current draw of the fuel
pump circuit checked.
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