Helpful tips

How do you clean the idle air control valve on a Miata?

How do you clean the idle air control valve on a Miata?

Yes, the IAC can be cleaned, but that does not guarantee you will fix the problem if the problem is with the solenoid and not with the valve itself. You can spray the cleaner into the IAC ports, then shake out the cleaner. When I did it, I sprayed some Tri-Flow lubricant in there and shook out the excess.

How do I reset my idle control valve?

Turn the ignition ON and leave on for several seconds then turn the ignition OFF to allow the ECM to reset the IAC valve. You should be good to go.

Can you clean an idle air control valve?

Cleaning an idle air-control valve can keep you from buying a new part, but only certain idle air-control valves can be cleaned. The idle air-control valve must have a spring-operated valve for cleaning to make it work.

What is a CAS O ring?

Turns out there’s a part right behind the valve cover that is called the “crank angle sensor.” Also known as the CAS. Apparently it senses the angle of your crank. My crank is always angled. Obvious enough. That part has an o-ring that is known as the “CAS O-ring” and it is known to harden and leak.

How do you test an IAC valve?

Here is how to test and clean the valve:

  1. 1) Open the hood of your vehicle.
  2. 2) Pull the electrical plug off the control valve.
  3. 3) Take out the idle control valve and flip it over.
  4. 4) Take your voltmeter and set it to “Ohms.”

What is idle RPM control on a Miata?

  The ISC system has two components exclusively dedicated to idle air / rpm control.   Those are the ISCV and the AV (Air Valve).   Other components play roles in the idle rpm, including the IAS (Idle Adjustment Screw), which is part of the throttle body.    This screw may or may not be under a “Blanking Cap”.

What is the control system on a Miata?

  This system consists of the air valve that functions only when the engine is cold, the ISC valve that works throughout the entire engine speed range, and the control system. The “control system” mentioned in this description is primarily the ECU (Engine Control Unit).

Are there any issues with my 1991 Miata?

Not the least expensive, but if you have a 1990 or early 1991, you may have a Short Nose Crank. These are known to fail and cause engine running issues. Search engine use with the words MIATA SHORT NOSED CRANK should get you more reading than you wanted. Check the clean air crossover tube for leaks and cracks.

What causes a vacuum leak in a Miata?

Instructions are in the Garage. New throttle body and ISCV gaskets. It could be an internal leak. Remove the EGR valve and test it for leaks. If you can blow through it, it’s bad. This is a vacuum leak you can’t hear when the engine is running.