I have a '91 240 that the gas gauge was broken. When I went to check the sending unit, I found that the wires at the gas tank were no longer connected due to rust, etc. at the tank. The car still ran fine. I replaced the tank with one from my '89 240DL and things are fine.

Is there an in-tank fuel pump on these? I always thought there was but since my '91 ran fine (no symptoms at all) without any wires connected to the tank, I began to question whether it has an in-tank pump (there are only 2 wires) or whether it does much.

 

I AM NOT SURE IF THIS WILL HELP OR NOT BUT I HAVE AN 86 240DL. WHEN I REMOVED THE ACCESS PANEL ON MINE THERE ARE TWO SETS OF WIRES BUT THE ONE THAT GOES DIRECTLY TO THE TANK HAS THREE WIRES ONE GROUND AND I GUESS ONE FOR THE GAUGE AND ONE FOR THE PUMP. AT THE SAME TIME I HAVE RAN TESTS ON MINE THAT BYPASSED THIS PUMP. AND IT STILL STARTED AND RAN FINE I BELIVE IT IS MORE OF A HELPER PUMP TO RELEIVE SOME STRAIN ON THE MAIN PUMP.

 

Thanks for your input. I guess I really won't worry about it working or not as the car starts and runs fine.

 

My 86 240dl lost the main pump because the in tank pump failed. The main may have taken a while to fail. The mechanic said main pump needs the in tank pump to operate properly. Cheers

 

Well, I did replace the entire gas tank. Hopefully the new tank's pump is working. Anyone know how to tell if the in-tank pump is working? I can hear the main fuel pumpbutnot anything from the tank.

 

If the in tank pump is not working, you'll notice a significant loss of power at speed. If it seems to have normal pick up, you're doing fine.

 

Actually, my wife and daughter complain that the '91 doesn't seem to have the pickup that our old '89 wagon used to have. However, I think this is off the line and at lower speeds. It seems to do better at higher speeds (40-50mph).

I have had the '91 up to 70-75 and haven't noticed anything abnormal about the way it runs. When you say a loss of power, do you mean it will stumble when accelerating at high speeds or generally run bad?

Thanks for the help