Miata stumbles, wont fire

[Andy Bettencourt]

Cas?

Cam Angle Sensor.

[mossaidis]

gracie

[JLawton]

Isnt that fairly common on the Miatas?

[Mike Mackaman]

I am a Nissan guy, so I really don't know. Bottom end is still not as strong as it has been. Once the VIR race is done this weekend, I will dig further on this, just happy to have it running again.
Mike

[Mike Mackaman]

OK, it runs and drives, but the more I drive it, the more I realize that there are/were two problems. The low RPM power is still not there. I mean it is even hard to get the car rolling, but at WOT and greater than 4000 RPM, it is like a rocket ship.

Tell me if I am crazy here. When the cam timing was all messed up, and I was moving things around and taking the valve cover on and off so much, I put the PCV valve hose on the manifold and left it out of the valve cover. The car backfired so hard it shot the hose and PCV valve about 20-30 feet across the yard! I wonder if I ruptured the diaphram in the fuel pressure regulator. That would cause it to idle rich, and have no power off the line and then get better with throttle and RPM. I had been thinking TPS, since it doesn't seem to have good power on part throttle tip in. Like the accelerator pump wasn't working right. But then I realized that it wasn't popping lean it was just flat, rich! Then I realized that the vacumm drop changes the fuel pressure to richen it up like an accelerator pump, so if we are already at max fuel pressure, it would act just like it is.

Guess I will be putting a tee in and hooking up my fuel pressure tester tonight!

Mike