Dashpot
 

Does anyone know what's up with the dashpots on the early 1.6 Miatas? My 1990 Miata stalls out when I press down on the clutch. When I spray some WD-40 on the dashpot the car runs better for a while, and then after a few weeks the car starts to stall out again. Any advice?

I had to google dashpot to figure out what the hell it was.

I still dont see how a dashpot relates to your clutch.

I would say you have a leak somewhere around your throttle body. I don't think the dashpot is actually connected any way to the airflow. Check all of your intake pipes for cracks. The Idle air control valve is on the underside of the manifold, so it could be possible that when you spray down the dashpot you are getting some on the tubes that lead to that.

Thanks very much for the suggestions. My clutch is fine, and I don't think that I have any problems with my airflow. I've checked everything out. When the dashpot is lubricated the car runs perfectly. From what I have gathered the dashpot is a mechanical component (looks like a simple spring) connected to the throttle that automatically adjusts the fuel flowing into the engine when the car is idling. I should probably just buy and install a new dashpot. It's only a $50 part.

or you should adjust your idle speed screw...better yet, clean the TB's butterfly valve.

all the dashpot does is slow the rate of the throttle closing...

Definitely not your dashpot.

OK, thanks. I will play around with the idle speed screw and clean the TB, and see if that helps. I appreciate your advice.

If the dashpot is seized in the throttle-closed position he could get a stall out. It would be linked to the simultaneous event of him backing off the throttle and pushing in the clutch (making it appear the clutch is the problem).

One way to test would be to pull the dashpot rod to fully extended and clamp it somehow. You'll have a really high idle but you'll confirm or eliminate the dashpot.