and another picture:

 

How likely is the key that positions the harmonic balancer to shear?
I have not been able to take the harmonic balancer off, even with my impact gun. But the mark on the harmonic balancer(not the timing pulley behind it) lines up with the T on the crankcase when the cam pulleys are positioned correctly.

 

btw, i appreciate your help, tanprotege

 

The key/key way are not likely to fail. but it has happened before.
I was able to get the harmonic balancer off by the means of gentle persuasion: taps with a 2lbs sledge. A gear puller might work as well.
And you are welcome. I hope together we get you back to zoom -zooming.

 

Looking at this random Mazda DOHC diagram,http://cdn.2carpros.com/diagrams/1327/large.gif
With number 1 cylinder at TDC, the I on the Inlet cam should be at 12 o'clock & the E on the Exhaust cam should be at 12 o'clock.

But this one http://i.fixya.net/uploads/images/daves944.jpg shows the timing marks at 90 degrees.

 

Grim:
that's why it is so important to know the difference between 'precise' and 'accurate' even if you are neither.

We try to figure out the '02 2.0 liter engine.
Unfortunately my Haynes manual covers only the years '90 to 2000.

Accidetalprotege has not been able to remove the harmonic balancer. Given how difficult it is the get a straight-on view of the affairs and the fact that all 4 cylinders lack compression to the same degree I am sure that the crank timing cog is off TDC by 1 or 2 teeth.

This guy also had difficulty lining everything up correctly and succeeded in the end:
Mazda Protege 2002 Timing Belt | Getting back into it

 

service manual ive got says the marks face inward

 

Weekend update:

First, I got hold of a second compression tester and recorded the results:

1) 45 psi
2) 20 psi
3) 15 psi
4) 35 psi

Second, I got myself a Harbor Freight leakdown test kit and did some testing. After going back to HF to get another set of pneumatic fittings because the ones that came with the kit were **** and didn't fit my lines.

I measured 5 times for each cyl at TDC, here are the averages:

1) 65%
2) 69%
3) 71%
4) 68%

All to be expected.

I removed the intake boot and noticed that on 2 of the cylinders air was coming out through the throttle body(cyls at TDC for each of my tests..). I can't quantify how much air was leaking through the valves but I assume it is not unreasonable for a cold engine with 150k miles to not have perfectly seated valves.

I tried connecting my compression gauge to the cylinder adjacent the cylinder being pressurized for each of my tests but never registered a reading. Which makes sense now that I think about it since the valves would just be open anyway.

What's most interesting is: On all 4 cylinders when the air was turned on the coolant level in the radiator bubbled or raised. !!!

 

.....which means you were blowing the air into the cooling system.
Your head gasket is shot.


I hate being the bearer of bad news.

 

I'm hoping that's all it is. Hopefully the heads still straight