Well bugger me sideways with a blunt pitchfork.....that is a serious oddity.....
The MAP tells the ECU what the manifold pressure is and to alter fueling to compensate for the larger charge of air. This I believe is controlled within the FIP by the quantity servo.
With MAP unplugged the ECU will default to a standard fuel map and the QS doesnt do much until engine speed change is demanded then it will begin adjusting fuel compared to accelrator ppositiin, engine load and speed.
With the MAP plugged in, the ECU will be contnually modulating the QS in response to manifold pressure and the other above parameters.
If the QS is faulty or loose inside the pump as it tries to modulate it could vibrate...or the solenoid could be bad and the vibration is the result.....
I think and could be as wide of the mark as my backside would be by being buggered with a pitchfork sideways!
The MAP tells the ECU what the manifold pressure is and to alter fueling to compensate for the larger charge of air. This I believe is controlled within the FIP by the quantity servo.
With MAP unplugged the ECU will default to a standard fuel map and the QS doesnt do much until engine speed change is demanded then it will begin adjusting fuel compared to accelrator ppositiin, engine load and speed.
With the MAP plugged in, the ECU will be contnually modulating the QS in response to manifold pressure and the other above parameters.
If the QS is faulty or loose inside the pump as it tries to modulate it could vibrate...or the solenoid could be bad and the vibration is the result.....
I think and could be as wide of the mark as my backside would be by being buggered with a pitchfork sideways!