How Replace the Ignition System, Adjust the Idle, Timing on 1991-99 Nissan Sentra, 200SX

This is a description of the process involved in doing a tune up on a 90 to 99 Nissan 200 SX or Sentra. You will need the following tools: a flat head screwdriver, 12 mm wrench, 10 mm wrench, sparkplug socket, 3/8 drive extension, and ratchet. We will be replacing the spark plug wires, sparkplugs, rotor, distributor cap, and setting the idle and bass ignition timing.

Parts:Spark plugs (NGK), spark plug wires (NGK), distributor rotor, distributor cap.

The first thing that we are going to do is replace the sparkplugs, you will be using NGK brand BKr7e spark plugs. You're going to want to remove the spark plug cables, pay close attention to which sparkplug reservoir each sparkplug cable came out of. Using your 3/8 drive ratchet, extension, spark plug socket begin by removing the spark plugs turning the ratchet in a counterclockwise motion. If the inside rubber grip of the spark plug socket does not grab hold to the sparkplug then you will need a small pen style extension magnet in order to remove the spark plugs. Once you have removed all of the spark plugs replace them in the same fashion in which you remove them using the ratchet in a clockwise motion. Be very careful when inserting the spark plugs into the sparkplug reservoir so that you do not pinch the end of the sparkplug gap to the electrode, if you do this the car will not run properly and probably misfire. Once you have replaced the spark plugs put it the spark plug wires back in the holes, but do not press them down as you will be changing them in a second. Take the spark plug wires out of the box and spread them apart, you are trying to locate the proper spark plug wire for each one that you will be replacing. All of the spark plugs will differ in length, the shortest one being the one that goes to the coil.

Remove the distributor cap using your 10 mm wrench, there are two 10 mm bolts that hold the distributor cap on each side of the cap. After removing and holing the distributor cap off you will realize that you're looking at the distributor rotor which is held on by one bolt. Use your flat head screwdriver to remove the bowl turning it counterclockwise, replace the old rotor with the new one that you purchased. After you have replace the rotor it is time to put on the new distributor cap. Install the new distributor cap by tightening the 2 10 mm bolts that hold it on, make sure not to tighten them very much because you could crack the distributor cap accidentally. Now it's time to replace spark plug wires, you will notice that the distributor cap as numbers on it, these numbers indicate cylinders that the wires go to. Go ahead and replace the wires with the proper length in accordance to the ones that are already existing. Now that you have replace the wires it's time to connect them to the distributor cap. The cylinders are numbered one through four beginning on the left side of the engine bay or the side of the engine bay that the crank pulley is located, number four would be the one closest to be distributor cap. Take the first spark plug wire from the left side of the engine bay closest to the crank pulley and plug it into the hole on the distributor labeled number one. You will now plug-in the rest of the spark plug cables from going left to right towards the distributor cap, again the one closest to the distributor Is number four. Once you have done this it is now time to set the base idle and ignition timing.

Turn on the car and rev the engine at 3000 RPM for two minutes, when you are done with this allow the engine to come back down to idle. The next step is to disconnect throttle position sensor located on the throttle body, it should be brown in color with three wires. Now that you have done this you need to connect your timing light to the poles on the battery. Now that the timing light is beginning to pulse you need to loosen the distributor it self via the two possibly three 12mm bolts that hold it in place. All were doing is loosening the bolts so that you can move the distributor clockwise or counterclockwise, take your time and light over to the side of the engine where the crank pulley is located and shine the light at the crank pulley; you will notice a series of marks that go from left to right they are -5,0,5,10,15, 17, and 20 degree marks. Take notice at where the pointer above the crank pulley is located in relation to these marks, if it is located on the fifth mark from the left going right then your ignition timing is correct. If it is not located on that mark then you will need to lean over and rotate the distributor clockwise or counterclockwise in order to achieve the fifth mark on the crank pulley. Now that you have your ignition timing set correctly it is time to adjust the idle. You will need another person to help you do this by sitting in a car and telling you what RPM the engine is at while you adjust the idle. On the left side of the engine bay near the strut tower on the intake manifold you will notice a big plastic screw that has a Phillips head indention. If you turn the screw counterclockwise it will raise the idle, if you turn the screw clockwise it will lower the idle; turn the screw and adjust the idle to approximately 750-850 RPMs. Once you have achieved this you will need to turn off the engine, once you have turned off the engine go ahead and plug the TPS (throttle position sensor) sensor back in place and restart the car. The car showed idle at the appropriate rpm that you set it at, if it does not then repeat procedure. Once you have done this you have completed a basic ignition and idle tune up for you 1.6 or 2.0L engine.