Miata Stalls When Driving Diagnosis and Repair

In this video we demonstrate a relatively common issue on Miatas where it slowly loses power over a short drive and ultimately stalls out. This can be a very difficult diagnosis, the owner of this car has tried replacing everything under the hood with no improvement in symptoms. The car will also begin to buck / surge and backfire before ultimately stalling because the fuel pressure is slowing dropping as the pickup becomes more clogged.
Link to follow up video showing the inside of the fuel tank:
• What's Inside My Fuel ...
Tags: Mazda Miata NA NB NC ND MX5 MX-5 Fuel pump fuel pressure drivability 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

[@aubreywhitley6889]

Great video on a hard to diagnose problem. I good reminder to fill you tank, hopefully with ethanol free gas, and use gas stabilizer before storing. I'd love to a see a video of the steps to replace the tank.

[@immortanautomotive9221]

Yeah exactly right, a full tank would totally prevent the issue. I'll see if I can make a video when we do the tank replacement. One thing I can say is it would NOT be a fun DIY project, it's a full day of work with the full resources of the shop. If you check out our Instagram or Facebook page you can see some pictures of the process, I think there was one around November of last year.

[@davidspl]

Good informative video of the miata MX5

[@DanielRodriguez-gh2xu]

Amigo amigooooo me pasa lo mismo y estoy desesperado porque no se qué es, es la bomba o el filtro de combustible? Gracias enserio por tu vídeo slaudos desde Guatemala

[@DanielRodriguez-gh2xu]

Otra cosa el Miata tiene interruptor de inercia apagado de combustible? Esque pensaba que eso era

[@redneckcrawler2367]

I have a question for you. Its not a problem, just more of a curiosity. I have a 90 and the car runs great on 87 octane. It runs like absolute crap on 93 or ethanol free 93. Only guess i have is coil, but previous experience on other cars if the coil is going it runs like crap regardless of what gas is in the tank. I firmly admit im just a parts changer, you tube certified mechanic at best.

[@immortanautomotive9221]

Well luckily there’s really no benefit to using 93 so you can stick to 87 for now. I agree there should be no perceived difference between the fuel types. Maybe the source you got the 93 has some kind of contamination or water in it? Miatas are very sensitive to “bad gas”

[@mxn008]

so would you suggest buying a new tank?

[@immortanautomotive9221]

Depends how bad it is inside, but usually that’s only way to be sure it won’t happen again

[@Ragingcroc]

wish I had seen this video 3 years ago when I had the same problem on my 90 miata lol

[@immortanautomotive9221]

Yeah that's a shame, but I appreciate the confirmation that this will help others!

[@82raptor]

Operator error.