Here's the original thread on this: http://www.brickboard.com/RWD/index.htm?id=1399417&show_all=1

What I originally believed to be my main pump was in fact the in-tank pump making a loud whine. I discovered this by removing the main to swap it out with a used Bosch unit. With the main assembly off, I decided to jumper the in-tank pump to check the flow (I didn't do this the last time I went through this job). I heard that annoying whine that I've always heard, and noticed that the flow was poor. That 1/2" fuel line's output was about 1/2 capacity.

SO, I pulled the in-tank again and noticed that the bag filter looked like it was getting sucked into the pump input. I opted to get rid of it and replace it with some steel mesh that I had lying around. I stretched it over the orifice and tethered it on with some thick 0-rings. I then placed the pump in a can of fuel, wired it to a battery, and circulated fuel with it through 5/16" fuel line. It pumped strong, but was totally noisy. I also tried this w/o any filtering on the pump and got the same result. I verified that all ports, tubes and hoses were free of blockage, put it all back together, and.......

The in-tank is still screamin'. The Bosch main definitely operates smoother than the aftermarket that was in there, though. Car starts and drives great. Hard acceleration is a little bumpy, but doesn't seem to be sputtering or missing.

Fuel filter has less that 1000miles on it.

Pulling #4 fuse doesn't kill the in-tank, which I find odd. The wire color even matches (red w/yellow stripe).

Anyone know what's going on?

Charlie
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1985 244DL B230 M46 170k