Hi Guys,

I am in the process of getting '77 280E 123 model running again.

I'm having trouble with hesitation and lack of power making the car to be undrivable.

It seems to get the worse as the engine gets warmer.

Idles fine when cold and seems to rev ok with a bit of a miss here and there.

Once a bit of heat gets into the motor the idle drops and turns lumpy and it just doesn't want to rev.

I detached the warm up regualtor from the block and disconected the electrical conection.

To see if it would make any difference.It seemed to idle properly for a bit longer and could be driven under 15 klms per hour for about 5 -10 minutes.

Then returned to a lumpy idle and and no power/stalling condition.

I checked the voltage to the fuel pump when cold and got 11.5V and when it was warm i had 10.5V is this normal? would this be enough to send the pump lazy and reduce the flow of fuel? and cause these problems?

Thanks for any help.

Jeremy