To my dismay, I have to revive this thread. Once again, I am getting low gas mileage, but worse yet, I am getting very hesitant starts. The car turns over strong for 2-4 seconds, finally catches, then is followed up with misfiring for another second or two. Once the car is idling, it is relatively smooth (it's still a 4 cyl). I pulled my plugs today and found spark plug in cyl #2 was slightly white whereas all the others are normal. I compression tested and got right around 195 on all 4 cylinders. With the key on (not started) I can hear a high electrical humm near the injectors, but I am not sure if that is normal. I had an issue where I wasn't getting spark a few days ago, and after plugging back in and out my CPS that issue was gone. My thoughts:
Injector(s): If 1 injector was bad enough to cause a bad start for the hole engine, wouldn't my idle be rough? Also, looking at my WBo2, I am idling/cruising around stoich, and at WOT it'll go down to 12.5ish.
CPS: If my Cps was going bad, wouldn't I be getting a bad idle? Also does not explain cyl2 lean condition.
ECU: If the stock ECU was bad (this car was kept in a garage most of its life) I feel like there would be other problems. This is so rare I cannot imaging that being the issue.
Ignition Coils: This is the second brand new OEM Mazda ignition pack....I really doubt 2 would just "fail." I gapped down to .040 and no difference.
I am totally out of ideas....I feel like I have tried everything and nothing will make sense of the issue.