More tests:

Put beefy old vacuum gauge on the manifold, holds 17-18 and really stable.

Hooked up an old school "Engine Analyser" I got at a yard sale. And used the tach on it, and discovered that the in-dash tach is not accurate. I re-adjusted the idle and timing to 11 BTDC with TE1-E1 Shorted. It does idle and run a little better. But still has the same problem.

I also noticed that the RPM is not precisly stable and bounces about 50 revs or so in about the same frequency as the movement of the timing marks.

Hooked up a basic Air / Fuel meter.. readouts look to be normal from what I can gather. I don't have experience with one of these things. Only strange one is that it cycles back and forth when idling HOT. not sure on that one.

Checked the PAIR valve system and its all working in spec. I did disconnect the vacuums to it but still no change.

Inspected the EGR and its all seams to pass the mustard as well.


Where would I find and how do I test the Engine Coolant Temperature Sensor?