After a few months, I finally had a chance to follow up on my old and forgotten thread.

Quick background: Intermittent open somewhere in the fuel pump circuit. Left me stranded twice in July and August, even after replacing fuel pump in July.

Reading, re-reading, and repeatedly mindf***king self over wiring diagram led me to the conclusion that the wiring issue was with the sender. (Thanks Drew!)

On Monday this is what I found:



At least it was obvious!

Sender was replaced with a NOS GM unit. Reused Bosch pump installed 3 months ago. New filter. Blew out EVAP line. All seems well (for now).

So how the heck did this happen?

A little more background: Failed sender was an aftermarket unit replaced in 2016. Pump was also replaced in 2016 with a Walbro. The only indication of an issue was somewhat increased noise (from an inherently loud pump) after long periods driving in hot weather. Tank pressure would get high (took off gas cap and a lot more pressure would release than usual) The "UFO" was cleaned and tested ok. This happened a year before the failure. Could the high tank pressures have caused the fuel pump to draw too much current and overtax the wire? Is there anything I can do to prevent that? Should I just chalk it off to a crappy Chinese aftermarket sender?

Thanks!

 

High pressure in the tank actually makes the pumps job easier. I would suspect either a crappy wire, or maybe a high-draw condition with the pump. Putting a fatter wire there sure wouldn't hurt you.