What causes a Miata to forget which spark plug is which?

What causes a Miata to forget which spark plug is which?

In case you forget which plugs is which, refer to the firing order diagram below. This is caused by breakdown of the insulation on the wires which results in the spark arcing through the insulation to the metal valve cover instead of through the spark plug electrodes. Dave Weckerle sent in this bit of information regarding hesitation.

How do you check the ignition on a Miata?

An easy way to check is, pull #1 spark plug, and drop the dipstick down the hole. Turn the motor by hand and watch the dipstick until it peaks at top dead center. This will tell you the crank shaft is at TDC. Now check to see where the timing mark on the crank pulley lines up.

How can I tell if my Miata is at TDC?

An easy way to check is, pull #1 spark plug, and drop the dipstick down the hole. Turn the motor by hand and watch the dipstick until it peaks at top dead center. This will tell you the crank shaft is at TDC. Now check to see where the timing mark on the crank pulley lines up.

What should the idle RPM be on a Miata?

Factory spec for the Miata specifies standard timing as 10° before top dead center (10° BTDC) ±1° at idle speed(850 rpm). If your timing is advanced more than this, you may experience pinging under some conditions. Dirty spark plugs Metallic burr in cylinder

Why are the spark plugs on a Miata not straight?

The ceramic insulator on the spark plug has straight sides – not ridges like the factory NGK plugs. As a result, the rubber boots on the spark plug wires sometimes grabs the ceramic insulator so tightly that the boots stay behind when the wires are removed.

Why is my Miata engine not idling properly?

There is another possible cause for hesitation and poor idling: Water in the engine – if you clean the engine bay with a pressure hose and spray the top of the engine block, you may have troubles. The rubber seals on top of the spark plugs aren’t so great, so some water can seep into the cylinders, particularly the no. 1 cylinder.

How long do ignition plugs last on a Miata?

OEM plugs usually are somewhere in the middle. Common Problem! The factory ignition wires on the Miata only seem to last between 30,000 and 50,000 miles. If you are experiencing misfiring and hesitation and you haven’t changed your wires, this is most likely the cause.

An easy way to check is, pull #1 spark plug, and drop the dipstick down the hole. Turn the motor by hand and watch the dipstick until it peaks at top dead center. This will tell you the crank shaft is at TDC. Now check to see where the timing mark on the crank pulley lines up.