Hi All,
My 2001 ML 320 (133K miles) had to be towed home today for the first time. It starts fine but when I press the accelerator down it stumbles and dies. No check engine light, but it has thrown a couple of codes over the last month (300 and 303 code) I just replaced the plugs with OEM Bosch and the crank position was replaced a few months ago. I was thinking fuel pump, but I wanted to check here first. Please help and Merry Christmas to all!

John Zazella

 

could be your fuel pump as you stated but when they go they go. does the car stall out when you hit the gas? could also be a mass air flow sensor issue. fuel filter?

 

The pump must be working because it starts and idles fine. I will try the filter first (is it in the gas tank or in line?) then the MAF. The MAF is the sensor in the intake tube, just downstream of the air cleaner, correct?
Yes, it sputters and stalls when the pedal is pressed. In neutral, it will rev a little (2 or 3000 rpm) but when you put it in gear, it shuts off. Thanks a lot for the response!

jz

 

Well I put the new style fuel filter and a new MAS sensor today. Didn't fix it. I'm ready to cut this thing up into little, expensive pieces.

 

It was the fuel pump.