If your engine is hard to start or idles poorly, you may want to check your speed sensor. It senses movement of the flywheel and signals the DME to turn on the fuel pump. When set correctly it is positioned very close to the ring gear teeth (0.8 mm). If set too far away from the gear, it is slow to sense movement, too close and it gets chewed up by the ring gear.
Here's a simple tool that will help to correctly set the sensor bracket. Just adjust the tool's bolt to be 0.8 mm longer than than your speed sensor and insert the tool into the speed sensor's holder. Secure it there with the sensor's attaching bolt. Adjust the sensor bracket so that the bolt contacts the ring gear and secure the bracket in that position. Remove the tool and install your sensors.
Note: never assume the sensors are made to a common length - they should be the same but sometimes they vary.
Alternatives: there are all sorts of ways to do this little job. The most common is to clue a 8mm washer to the bottom of your speed sensor. Install and adjust the bracket so that the sensor/washer contacts the ring gear, then with the bracket secured, remove the speed sensor and remove the washer. Or you could use a machinist depth gauge.
The reference sensor does not need this procedure - it si just set to the bottom of the bracket's bore and it's clearance is adjusted via the height of the set screws that are inserted into the flywheel.
