550 No power

Hi, My 550 Maranello used to run fine with the ocassional Check Engine light putting it in limp mode.

Had a guy with the SD6 come over and check the car for it and not sure what he did but now it just idles with no response to the acceleration. WHile checking the car he could not find any codes about the oxygen sensor and therefore started checking the fuse box for dry contacts buy pulling out relays and putting them back on.

Already checked the fuel pumps (was not used for a while) and there is enough fuel and pressure so its definiltely some sensor issue.

Could the O2 sensors go to a certain point where the car wont run past 500 RPM.

What would the obvious things to check be w/o an SD tester in such a scenario. ANyone else had an issue like this?

 

Maybe there is english translation problem? So your car idles fine but you step on gas pedal and nothing happens? If true then check to see if you can change RPM of engine by direct turning of throttle body butterfly by hand. 550 is hardwired throttle cable not drive by wire electric throttle

 

Thanks.

Yes that is correct. Idles (not really fine but just about runs as idling is way below the normal smooth idling).

Tried opening the butterfly valve by pushing it manually from the Engine bay but no difference.

With the throttle open you feel the car is trying to rev slightly higher but no real change other than maybe 100 to 200 RPM more.

Its not running rough either as in running on less than the 12 cylinders.

Just no power. In other cars this would usually be an issue of MAF sensors?/

 

Sounds like not running on 12

 

It gets enough of petrol?

 

Removed the pipes of the 2 fuel pumps in the back and saw a fair bit coming out from both pumps when turned over. Having seen the similar pumps fail on the Maserati and Ferrari 456 (due to the car being unused for a long time), I felt that there would be some black fuel or the fuel coming out at low pressure in case of fuel issues. Also checked the front release valves on the injector rails and quite a powerful squirt when released. Unless there is a fuel pressure regulator issue or the prev guy accidentally knocked off some vaccum hose its hard to pin point. When the car goes through its ignition check, the display comes to the GREEN CHECK OK each time with no issues.