Ferrari back from service (engine replaced) and car shakes rough at idle but seems to run fine otherwise. Is there a learning curve with the ECU to find the stable RPM like most modern cars or is there an idle adjust screw or MAF adjustment that could be tried? It's T-minus 48 hours from going back to mechanic. Thanks all scott 96 engine
The first thing to do is to try an "idle relearn". Go to the passenger side access port under the bonnet. Turn off the electrical power for 10 seconds then back on. Now start the car with the A/C off and let it idle for 10 minutes. The ECUs do learn the current condition of the motor. The ECU (at lest the 2.7s) need a cuple of minutes at each RPM*throttle setting to go through their trials and optimize the engine mixture for that one RPM*throttle position. The RPM bands in the 2.7 are about 250 RPMs wide. The tricky 'zone' is the 2250 RPM through 3000 RPM band. There is an ECU controlled idle speed regulator control that the ECU uses to set the idle speed at 1050 RPMs. But, yes, there is an idle speed adjustment on the throttle linkage. It is rather difficult to access (especially with a hot motor). See attached image: 1: cylinder pairs are set by screw 3 2: bank to throttle cam are set by screw4 3: idle speed is set by screw 2 4: manometers go on post 5 5: per cylinder idle bypass is number 1 6: if screw 3 cannot obtain balance between cylinder pairs use screw 6 to gain travel, then go back and use screw 3 Image Unavailable, Please Login
gas box and manometers are jobs for professional service people. If to lean...and these cars have enough problemns with valve train components..
