help on 1988 740 turbo possible fuel pump

Seems more likely to be the fuel filter. Has it been changed recently? it should be changed every 60,000 miles. It is also possible that the in-tank pump may be on the way out or has developed a blockage or air leak.

Cheers, Peter.

The relay likely has cracked solder joints, but since you noticed the sound changing the pump or filter may well need replacing, but I would guess fixing the relay will likely get you back on the road. You should have someone measure the electrical draw of the pump though, it should be under about 10A, it's pretty easy to do for anyone with a multimeter.

Definitely start with the fuel pump relay. Also there may be another relay under the hood, a black 4 pin relay under the hood, usually mounted on or near one of the shock towers. If the main fuel pump is still noisy, then probably the in tank pump or the hose from that pump to the fuel sender has failed.

Thanks guys. I am replacing the fuel filter and fuel pump tonight. Not too much $$ to replace anyway. I'll check the relay out also. The main relay is in the fuse panel right? which one is the pump relay? (which slot? hard to get in there).

Is it in the center console like on an '87? If so the entire fuse box/relay panel comes out, just remove the cover over the cig lighter, remove the screw, pull that pocket out, then pull the fuse box forward and up, it'll come out of it's cave on wires and you can access it easily.

You've probably done it already, but the fuel pump relay is the white one on the right in the middle row. If you remove the little storage box and lighter, access becomes easy.

Hello again! OK, I replaced the fuel filter and held off on the pump....and thought everything was ok. anyway...this is what is happening. I have noticed when I get down to a little less than a 1/4 tank the problem happens And thinking back, it was low on gas the first time it happened. Does this sound like something might be in my tank?