Mercedes A class mistery

[nazz2]

hi
I had a call from the grage to sort out the 1999 merceds a class,petrol,with 2 botton flick remote like vw.
The garage had changed the fuel pump,and after that customer complains that if you put the key in the ignition ,and try to start the car,she would not start,unless you take the key out ,and put it back in the ignition,and the car starts,and starts after that.

Does the new fuel pump has to be coded to the car?also what would be the likely problem,thnx

nazz2

[ntuser]

Does the engine cranks at a first start attempt?
How much pressure at fuel rail?
Does the pressure drops en immediately after engine stop?

[nazz2]

hi
no as i have mentioned the car cranks but it does not start,then you take the key out and put back in then cranks and starts,if you want i can ask them to check the pressur,but if it starts the second atempt,i dont think it would be fuel issue,would it?,thnx

nazz2

[ntuser]

Try to crank at 1st time longer 15 sec. Does it starts?
Try to crank at 1st time 2-3 sec. Does it starts easy at 2nd time?
Measure fuel pressure (connect guage) before 1st start attempt.
Backpressure valve in new fuel pump may be stick.