I have a '90 240 that I took for a highway drive a couple of weeks ago. Upon return, I noticed a slight hesitation when accelerating from a stop. When I shut the car off, I heard a distinctive moan coming from the fuel pump.

My first thought is that my in-tank pump is starting to go. This weekend I tried to verify the diagnosis. Put a jumper from fuse 6 to 4 - couldn't hear a thing from the tank. I did the old screwdriver as stethoscope trick - still silence.

I have '91 240 as well so I tried the same on it - nothing but silence. Is it me going deaf or are these tank pumps really that quiet. Or do I just by chance have two cars with non-functioning tank pumps.

Any thoughts?

 

does either of the cars run ?

 

The absolute, definitive test for the in tank pump is to pull the feed line at the back of the main pump. Bump the key to the on position for a sec...gas should flow immediately from the tank. Obviously, do this in a safe area and with a suitable receptacle under the car.

 

In this case both cars run fine. I really haven't had any other issues other than the hesitation from a stop. That occurred only once on the one car.

First I'll make sure I have power going to the pump. If so, I'll then check by pulling the hose and running it (into a gas can of course) to see if gas flows.

Thanks for the help.