Quote:
Originally Posted by ioang26
The air screw is the idle air mixture screw on the top of the Fuel distributor which uses the Allen key to adjust.
Yes, I get a constant 20% Duty cycle and 70% when the engine is off but ignition on.
How do I check/test throttle position switch or air flow sensor?Do I unplug it to see if it will change the cycle value?
|
The "air screw" to which you refer is actually an adjustment of the initial position of the fuel metering plunger in the FD. With the EHA disabled (unplugged), it can be used to set the basic open loop mixture to be approximately stochiometric. This, unfortunately, also requires that the EHA has been adjusted to its basic position so that the lower chamber pressure is ~ .4 bar (5 psi) less than system pressure at an actuator current of 10ma.
The throttle switch can be checked for continuity in both the closed throttle and WOT positions. Unplug the switch connector, check between pins 1 & 2 on the switch for closed continuity, and between 2 & 3 for WOT.
The air flow sensor potentiometer can be checked by slightly loosening the plug so that the pins may be probed without disconnecting the plug. With engine running, pins 1-3, 4.5-5.5V; pins 1-2, .5-1.5V.