I think you have a side seal issue on the front rotor...and they look a bit low depending on cranking speed.

With the sluggish warm starts you are likely on the downward side of needing a refresh

 

I can't say what the cranking speed was, other than it seemed pretty slow. The mechanic installed a rebuilt starter, which cranks faster, but he didn't do the compression test again. Although cranking speed is improved now, it still seems reluctant to start when hot. Tapping the gas pedal when cranking seems to help it ignite. What makes you say it looks like a side seal problem?

 

The one out of 3 pulses is low on that rotor. If it was an apex seal it would result in 2 low pulses for that seal.

Have you tried a decarb? Sometimes that can help if the seals are sticky with carbon

 

I haven't tried the decarb yet but I think I will. I'll post back after I try it in a few days.

 

What you said makes a lot of sense. Each apex seal actually provides compression for two rotor faces, only on different ends of their surfaces.

Well, my SeaFoam decarb task is on hold now, for a week or so. I discovered a leaky coolant hose which has to be replaced before I can run the engine before/after the treatment.