I have an 89 244 whose relatively new main fuel pump is quite noisy. The noise started after replacing the intank pump which was inoperative.

In the past I have cured a noisy pump (in combination with a good prepump) by replacing the fuel pressure regulator. When I experienced the noise with the new prepump on this car I immediately changed the fuel pressure regulator. Unfortunately the noise remained.

I haven't tested the fuel pressure at the rail yet, but intend to do that; perhaps I got a bad regulator. Any other ideas on eliminating the annoying noise? Thanks

Randy

Randy, is there any possibility the fuel return flow became restricted in the course of replacing the tank pump?
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Art Benstein near Baltimore

Art,

At this point I would have to say anything is possible. I wonder if there is a standard amount that should flow out the return in a measured amount of time?

Perhaps I should just run a hose from the fuel pressure regulator into a container. I could start the car and see if the noise was gone; at least that would let me know if I needed to check out the return more closely.

Thanks for the tip.

Randy

Yes, I think running it into the lawnmower gas can is a great idea. I didn't imagine that, but remembered that cute caricature in the green manual of a technician with his cheeks all puffed out of proportion, blowing into the return line.

I was just thinking how the return line is that hard thermoplastic from about the axle to the fuel tank, and how easy it might be to get it kinked in the process of pulling the sender unit.
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Art Benstein near Baltimore