Firing order diagram for 1986 GMC S15 2.8L - 1986 GMC S-15

ZJ Limited

• 17989 Answers
• Posted on Oct 05, 2009

SOURCE: firing order for a 1986 gmc s15

FIRING ORDERS

To avoid confusion, ALWAYS replace spark plug wires one at a time.

The most important thing to remember about the removal and installation of a distributor, cap or spark plug cable is that all wires MUST be labelled before they are disconnected. Keep in mind that these figures depict a firing order where the distributor cap terminals are relative to EACH OTHER only and they do not necessarily depict the tower positions in relation to the rest of the engine. This is true because any distributor which has been removed and reinstalled may have been installed with the No. 1 spark plug tower at any position (360 degrees) in relation to the rest of the motor, as long as the rotor aligned to the No. 1 tower when the No. 1 cylinder was at TDC of the compression stroke (valves closed, ready for the plug to fire). As long as the remaining wires were connected in the correct firing order sequence (depending on direction of distributor rotation) the engine will run. DO NOT EVER remove more than one wire from the distributor cap at a time unless you tag ALL wires and towers to assure proper installation.



Fig. 1: 1.9L engine . Firing order: 1-3-4-2 . Distributor rotation: counterclockwise



Fig. 2: 2.0L engine . Firing order: 1-3-4-2 . Distributor rotation: clockwise



Fig. 3: 2.5L engine . Firing order: 1-3-4-2 . Distributor rotation: clockwise



Fig. 4: 2.8L engine . Firing order: 1-2-3-4-5-6 . Distributor rotation: clockwise



Fig. 5: 4.3L engine. Firing order: 1-6-5-4-3-2 . Distributor rotation: clockwise

I hope help you with this (remember rated this help) Good luck.