Miata Gone Bad

My Miata has turned to the darkside. Often when it sits for a few days or more it starts up with pissing and moaning before it finally starts and then it runs great. Yet two days things changed. It cranked briefly then the idle dropped and sounded like it was running on one cylinder just before it died. Now it won't fire up.

Thoughts?

I think that it is telling me that it wants a new engine yet the current engine only has 267K on it.

Any help or direction would be great.

Signed, Lowskillz

Cam angle sensor, probably.

Tell us more about this car. Like a year.

In reply to Keith Tanner:

His garage says it's a 1990.

CAS is a good start, especially if you can borrow a known good one from someone. I'd also check the fuel pressure, just because it's good to know and that slow start doesn't line up with a CAS problem.

Javelin has it right.

I replaced the CAS just over a year ago yet that doesn't mean much. I will start there and thank you all!!

My wobbly-cranked 90 did that for a year before I figured the problem. Somehow it managed to run like a scalded dog thanks to variable timing but wouldn't start worth a damn. So check your timing too, or just watch the crank pulley when running. Mine would wobble visibly at idle.

If I can shanghai his thread, my 91 SE has an annoying long crank time when it's hot (~5-10 seconds), but instant when it's cold (i.e., hasn't been driven in a few hours and it's <60* ambient)..

Any suggestions? I've been meaning to diagnose it for about 5 years now, but it hasn't really changed and it's always started :)

WonkoTheSane wrote: If I can shanghai his thread, my 91 SE has an annoying long crank time when it's hot (~5-10 seconds), but instant when it's cold (i.e., hasn't been driven in a few hours and it's <60* ambient).. Any suggestions? I've been meaning to diagnose it for about 5 years now, but it hasn't really changed and it's always started :)

cold start valve/sensor. It thinks the engine is cold and is dumping excess fuel to help it start. Sort of like trying to start a carbed car with the choke on when it is already hot

Good idea.. I was thinking it was something like that.. I kinda wish it was OBDII so I could just plug in and see what the sensors are saying..

I'll remedy that problem with a MegaSquirt when I turbo it :)

Link The link above is to a You Tuber that shows how my car was running,

Sultan wrote: I think that it is telling me that it wants a new engine yet the current engine only has 267K on it.

There's no "only" about that.

But my money's on your problem being related to electronics or external mechanicals rather than needing a new engine.

Why are you running that much timing? Remember to jumper your diagnostic port, and then set the timing to 14*, and give that a go..

Wonko, check to see if your car has any codes. Even though it's not OBD-II, it does have some limited self-diagnostic capability. A bad coolant temp sensor should pop up there, for example.

I'd do the same on Sultan's car. Nothing may show up, but it's worth the 2 minutes with a paperclip to find out. Turn to page 73 in your copy of Find It, Fix It, Trick It.

I love my Miata! After days of not running today it cranked over. Then blew blue smoke for two minutes and once the idle stabilized it runs great.

Hopefully I don't get stuck on my way to work.......

Thanks again everyone.

Keith - Thanks for the idea.. I always forget about that except when it throws a light...