I brought home a 1990 240DL Wagon two weeks ago. It needed a new alternator which I replaced and then made a 3 hour drive without a problem. After I got it home I drove it a few times and it ran great. A few days ago I got in and it fired up fine but as soon as I touch the pedal it starts surging. I can't get it to rev up at all even though it idled smoothly. I have read many suggestions on the forum and tried a few thing:

-new fuel filter
-new fuel pressure regulator
-checked for vaccum leaks
-cleaned the throttle body
-checked grounds and wires

I am lost!!!!

Please help..

Thanks

 

Maybe tune up?
Maybe Mass Flow sensor bad?

 

I have considered the meter as a possibility but have no idea how to test..
I am sure it needs a tune up but I am not sure that would cause such a change from one day to the next.
It seems like the surge is being done by the computer since it will rev a little and fall exactly the same over and over.

 

Unplug the mass flow and start the car and see if it idles smooth. If it does the meter is bad.

 

I will give that a try.

thankyou....