What is the firing order for a 1995 Chevrolet Silverado 5.7L V8?
Hey Susan - and all Chevy V-8ers;
It makes no difference what year or type Chevy / Chevy V-8 you have. In the 52 years I've worked on cars the 1-8-4-3-6-5-7-2 firing (for Chevrolet's) has not changed. Notice - if you have removed the distributor, the gear on its bottom is helical (curved teeth) and it will rotate as you replace it, so you may have to remove and replace it more than once to get the rotor pointing in the correct direction = at #1 cylinder in the Distributor's Cap. One tooth off makes a BIG difference.
AND #1 piston MUST be at TDC (top dead center) = both valves closed and the #1 Piston at the exact top of its travel. Best to rotate the engine by hand (easiest with the plugs out) and using a breaker bar with (I think it is) a 5/8" socket, as using the Starter makes it rotate too fast. [A remote starter switch / hand starter switch can be used. But even this can be a bit too imprecise.] As the Crank (crankshaft) and Cam (camshaft) rotate, the Rocker Arms will move (rock) and the Valve Stems (top of the valves / the part of the valve you can still see when the Heads are installed) will move down and then up. The #1 Exhaust (furthest forward in the Driver's side head) will close (stop moving up), then the #1 Intake (2nd from the front) will do the same. As you look into #1 cylinder (via the spark plug's hole) you will see #1 Piston come up toward the top as the Intake Valve closes. When you see it - STOP. Then look to the Timing Mark on the Vibration Damper (the heavy metal disk on the bottom-front of the crankshaft, (about 8" in diameter and over 1" thick) for more precision. NOW, as you continue to SLOWLY rotate the Crankshaft the Timing Mark will rotate into view. Continue to rotate the Crank clockwise, as viewed from the front looking rearward, until the Timing Mark (groove cut into the Vibration Damper, lines up with the ZERO on the Degree Indicator (aka Timing Plate = a metal plate about 1" by 1.5" generally about 1 or 2 o'clock, looking aft/rearward, in relation to the Vibration Damper). This is TDC for #1 cylinder. You can then set the Distributor to (approximately) #1's firing position. (You may wish to chalk or somehow brighten this groove for current or future reference. I paint mine YELLOW, using a slim artist's brush, which really shows up in the Timing Light's bright flash. but white or yellow chalk works well. Wipe off the excess paint or chalk = any not IN the groove.)
If you go past #1 during your rotating it is best to go around again, TWO (2) turns, not just one, as one turn puts you on the Exhaust stroke (watch the valve stems again), not the Compression stroke. Or back up well past the Zero and come forward again (takes up any slack in the Timing Chain).
If you have not changed the valve's settings (removed the heads or other such action) then you should be all set to use a Timing Light and get the distributor set (rotated and secured ) in the correct position to give the Timing Advance setting recommended for your engine. This is done with the engine RUNNING, at idle, and with the Vacuum Advance Hose disconnected.
If you're wondering how to tell which valve is which, the Exhausts line up with the Exhaust manifold (casting) = E-I-I-E-E-I-I-E, on both sides.
The lengths of the Spark Plug wires will help you figure out which is which and (GENERALLY) only when you have #1 in the correct position will ALL the other wires reach their respective Spark Plugs. (Some after-market wire sets are not precisely cut to length and will be misleading.)
OR you can remove ALL the wires from the Cap. Put the Cap on the Distributor - choosing very carefully here - as the ROTOR inside the Cap MUST be pointing at the position in the Cap corresponding to the position you choose for #1's wire . Then wire all the rest in Firing Order (see the original answer). You can choose any one as #1 on the Cap, but the Rotor MUST be pointing at that position. If not, pull the Distributor and rotate its shaft (repositioning the gear's teeth) to make the alignment correct, to make the rotor match (point to) the Cap's chosen #1. In choosing, know that this position is most always pointing (roughly) toward the Driver's side Headlight.
That's $80 please!! OK, how about a hug? Murf
Hey Susan==It is 1-8-4-3-6-5-7-2 and the diat turns clockwise. The cylinders are numbered 1-3-5-7 on the drivers side and 2-4-6-8 on the pass side.#1 cyl is just to the right of front on the cap looking from front to back. GoodluckJoe