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1998 3.1 fuel pump job question=-


jamesmetairie
02-27-2015, 06:02 AM
226,000 miles on the original fuel pump.

Planning to have it replaced as preventive maintenance.

Are all the recommended parts in a kit ?

If not what parts do you guys recommend?


Thanks for any advice.

Crvett69
02-27-2015, 10:36 AM
you can ususally buy it as a assembly all ready to drop into tank or you can buy just the pump and take yours apart and put in the pump and new fuel pickup sock. either way you do it you should also replace your fuel filter at the same time

dplantz
03-06-2015, 11:12 AM
Mine lasted until 160k I replaced it with a Delphi Fuel pump, strainer and
Precision works wiring kit for fuel pump with a 1 yr warranty O'Reillys Auto parts
2 years later, still working fine

Schurkey
03-08-2015, 07:02 PM
I thought I had posted a "how to" for the fuel pump on an early W-body, but I can't find it now.

At minimum, you will want to replace the strainer, pump, in-tank wire harness, and fuel filter. Some folks will automatically replace the pulse damper; I did not because it didn't slosh when I shook it.

I will not replace a defective fuel pump without looking at the electrical system powering it. However, mine was replaced "just because" of the mileage, and a previous failure on my other Lumina at about the same mileage. The pump I replaced worked just fine.

For me, testing the electrical system involves measuring the voltage as close to the pump as I can access, WHILE THE PUMP IS RUNNING. Voltage is typically about two or three volts less than system voltage because GM uses under-sized wires that have excess resistance (but cost less.) I will also use a low-amperage probe to watch the amperage waveform on an oscilloscope to determine the current draw of the pump, to see that the current draw is approximately equal for every bar on the pump motor armature, and to verify motor RPM.

dplantz
03-10-2015, 01:44 PM
Well said, Shurkey. Now I remember I measured voltage back at the pump and discovered that mine was well below what the manual said as per your quote " Voltage is typically about two or three volts less than system voltage because GM uses under-sized wires that have excess resistance (but cost less.)"

jamesmetairie
04-24-2015, 07:45 PM
ac delco part # mu1788

i bought it from bumper to bumper.
it didn,t have a separate strainer.
the sales clerk says these new pumps have the strainer built into the unit?

my honest mobile mechanic is scheduled to do the job and if i ain,t got all the right parts it,ll cost us time and money.

anyone familiar with the new pump design?

Schurkey
04-24-2015, 08:20 PM
anyone familiar with the new pump design?
The service manual is your friend.

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