Well, the 93 940 is back up and running with the 88 780 fuel pumps installed. The job was relatively straight forward with just a little problem fishing the new main pump power wiring from underneath the car past the heater duct and into the fuse/relay tray area. I also tried running the car with just the tank pump and was pleasantly surprised that it fired and ran, although roughly, which should get it home in case of a main pump failure.

My biggest hurdle was adapting the broken 940 fuel level sensor to use the shorter unit from the 780 which also has a different resistance value. I ended up with a reading at empty through about 7/8 tank because the resistors are longer from the 940 (of course it would be different than any previous sensor)

The main pump and filter housing was a direct bolt up to the 940 filter housing with the exception that I had to turn the pump and filter end for end to get the existing high pressure line to bolt back to the filter. A piece of ½” fuel line and a 5/16”x1/2” hose barb adapter took care of mating the existing tank feed to the intake of the main fuel pump.

I don’t know if I recommend this for those that have money since it is probably easier to just replace the in tank pump, but, for my purpose of standardization between my three cars the project was a success.

Regards,
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Will Dallas, www.willdallas.us, www.willdallas.org, www.willdallas.com, www.dallasprecision.com 86 245 DL 222K miles, 93 940 260K miles, 88 765 GLE 152K miles, 88 780 246K miles, 93 Buick LaSabre 119,000 miles