Frequency valve troubleshooting

[DH5481@aol.com]

Looking at the Bentley again (for perhaps the 400th time) I see that it is
not confused - I am...  The LED test and voltage check are for different
terminals.  The LED test checks the input to the Frequency valve (+12V, ECU
signal); whereas the voltage test checks the +12V to ground.  This gives me a
little more to check.  Additionally in the Emission control section, during
the output diagnostics a duty cycle of 50% is supposed to be sent to the
Frequency valve (which I should be able to see right on the dwell meter).
For anyone needing this in the future, info to put all this together comes
from the Injection, Emissions, and Ignition chapters (plus the wiring
diagrams to trace it out - whew...).

Dave Head
87 5KCSTQ