328 no start

Gas, spark, air, and compression.
Check system fuel pressure and control pressure when cold. Check to see if you are squirting gas with the cold start valve.
Pull off a spark plug and check to see if there is spark.
Unless you have an obstruction in the throttle housing, you have air.
Since it was running before, you probably have compression.

 

Battery is always the first thing I check.
If in marginal charging power, like over night, it won’t start the car.

 

If no spark on a MicroPlex ignition system, but the engine cranks over well:

1. Unplug the RPM Flywheel Sensor and measure the resistance between the two pins on the unplugged sensor side = should be 600~1000 Ohms.

2. Unplug the TDC Flywheel Sensor and measure the resistance between the two pins on the unplugged sensor side = should be 600~1000 Ohms.

If you pass steps 1 and 2, plug them back in and retry (sometimes just unplugging/replugging can fix a bad connection). If still no joy:

3. Measure the AC voltage on the two pins on the RPM flywheel sensor (while still plugged in) during starter motor cranking. Should be ~2.0 VAC.

4. Measure the AC voltage on the two pins on the TDC flywheel sensor (while still plugged in) during starter motor cranking. Should be more than 0.1 VAC.

If you pass steps 3 and 4, but still no joy give a shout (but I hope you don't have to go there ).

 

Did you do steps 1-4?

 

No -- as I described in my PM response, I can't remember all the prior details nor even what I had previously posted so prefer just to have it all in a public thread.

This link should get you Service Bulletin 80-28 that describes all of the diagnostic measurements for the MicroPlex ignition systems (MED 120B for TR and MED 806A for 3.2):

https://www.dropbox.com/s/v8syps3qucxjj3n/Service Bulletin 80-28 microplex ignition.pdf?dl=0

If it wasn't one of the flywheel sensors, I'd still suspect single failure things that could take out both banks -- like no power or ground, but that document describes everything to test. Good Hunting!

 

Afternoon,
That sudden change could be the TDC sensor on the clutch housing. It's got two one is for the TDC and the other one is for the RPM.
They seem to fail all of a sudden...don't know why... they are interchangeable, very easy to replace and are inexpensive.

Hope this helps,

John.