Alfa Romeo Repair: alfa romeo 156 2.5 v6, alfa romeo 156, alfa romeo

Question
Hi I have a 1999 Alfa that always starts but has serious lack of power on driving.  When rev'd it misfires through the airbox.  Same performance wether the car is hot or cold.  Also it seems to be getting worse, it has been on 3 diagnostic tests which have been unseccful at diagnosing a problem.  Can you please help?

Thanks Tony

Answer
The first place indicated is the fuel supply because this part is not monitored by the ecu.  Check the fuel pump pressure AND volume. Inline pressure should be about 40psi and volume should be a pint in less than 20 seconds.

Because a problem like this needs step by step checking with the results of step one leading to step two etc., this is  the correct place to start the diagnosis.