Hi All!


First of all I grew up with Mazda's. My family had a B2000 truck, a GLC, and a 323. We also owned a Ford Courier truck which was a Mazda. Good tough autos!


My neighbor gave, yes gave me a solid 93' Miata. It's got a bunch of mile but it seems OK. And it promises to be a fun car!


The engine stumbles under load. And it appears to stumble while in a left turn (go figure).


I have replaced the air filter, plugs, wires, and the fuel filter. The fuel is fresh as I ran the stale out. I am hesitant to believe the engine is experiencing a mechanical fault as when it is not stumbling it idles smoothly and will rev effortlessly to redline.


Any suggestions would be appreciated,


JRC

 

Replace the ignition coil/coils. clean the MAF, clean the throttle body, check the fuel pressure, check the ignition timing, check for fault codes in the ECU/PCM.

 

It's old and may be experiencing a clogged cat too. In my experience a car with a clogged cat will idle nicely, but under load as you stated is when backpressure will build up. Try temporarily removing the cat and if that makes a difference. If it does either replace it with new, or run lacquer thinner through it several times to clean it out. I have to admit that I have no personal experience with this trick but have been told it works. And if the cat is really bad, what harm could it do to try it?