Re: C-GT tune up

[ejfluhr@austin.ibm.com (Fluhr)]

>Get a meter with a duty cycle setting (or dwell, and do the math, 50% =
>45 degrees on 4 cyl) and measure the frequency valve duty cycle at the
>unattached two wire connector floating around by your intake boot.  At
>idle it's supposed to be around 50%.  (this is the crude way of doing
>what your mech. did above)

Careful, here.  The earlier CIS engines (code WE) worked like this.

The later Coupe GT models used the 2226cc KX engine which had Bosch
CIS-E fuel injection.  On these cars, this connector measures the
duty cycle of the idle stabilizer valve, and should read 28% +/- 2%.

The best way to check these cars is to measure (1) the pressure actuator
current at the distributor, (2) the oxygen sensor voltage, and (3) the
ISV duty cycle (as mentioned above).

The pressure actuator current (DC) should move around 10mA for those
people moderately close to sea level (Bentley gives numbers for 
altitude vs PA current).  The oxygen sensor should fluctuate around
0.5V.

The best way I have found to adjust the mixture, using the 1.5mm (?)
tool, is in 1/16 of a turn increments.  Then rev the engine a bit,
and let it settle down to idle.  Check the PA current, oxygen sensor
voltage, and ISV duty cycle, make adjustments, and repeat.

Later,
Eric
'85 Coupe GT
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Eric J. Fluhr                                Email:  ejfluhr@austin.ibm.com
630FP Logic/Circuit Design                   Phone:  (512) 838-7589
IBM Server Group                             Austin, TX