How can I fix idle problem on my Miata?
Check the clean air crossover tube for leaks and cracks. Adjust the throttle cable to remove any excess slack. Be sure that the throttle still closes completely. There should be a very small amount of slack with the throttle plates closed. Check for vacuum leaks as stated above. If you find one, fix it and then set the Base Idle.
What causes a vacuum leak in a Miata?
Instructions are in the Miata.net 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.
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.
Why does my Miata have a short nosed 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. Adjust the throttle cable to remove any excess slack. Be sure that the throttle still closes completely.
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”.
How can I Keep my Miata engine from dying?
When spraying the cleaner you may need to keep the engine from dying by hand controlling the throttle control on the side of the Throttle Body.
What causes idle surges on a car ECM?
Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges.
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).