nowlings

Just wanted to share and give back since I have received so much help from fellow listers on this board. My 1980 (US spec) recently started to lose power under load intermittently. When the condition occurred I could not accelerate above 1800 RPM without the car falling flat on it's face. I had gone through a lot of the tests in wsm including fuel flow delivery and pressure rates, sensor tests with the DVM, etc. In the course of Diagnosis, I got the car up to speed on a lot of PM that was long overdue the the prior owner neglected.

What ended up happening was the fuel strainer in the tank became separated from it housing that screws into the tank. I found this after checking everything at least twice, but kept noticing a change in the pitch and noise of the fuel pump when the loss of power would begin to occur. I pulled the fuel sender from the top of the tank and found the strainer off angle sitting at the bottom of the tank. I pulled the lower hose off the strainer and started draining the gas. I got about 10 seconds of really good flow draining out then it almost stopped with just a trickle (see photos). I stuck a long screwdriver down into the tank and moved the strainer and suddenly, massive volume of fuel drained out again. This happened off and on while draining 17 gallons. I concluded that depending on how the strainer moved about the tank while driving, the detached strainer's position in the tanks was affecting fuel delivery to the pump.
I suppose the moral to the story is Do your PM people, and if filter or strainer conditions are unknown, best to change them out.

Thanks to everyone on this board!

Landseer

That's an important find. Thanks!