Spark Plug Wires Firing Order

[01SC02]

Classic mistake, took my wires out, ALL AT ONCE, can't firgure out for the lif of me which order they go in !!

It's for DOHC engine...

[electralux]

I believe it's 4-1-2-3.

[rc1488]

Originally Posted by electralux

I believe it's 4-1-2-3.

Correct

[adventureoflink]

Originally Posted by rc1488

Correct

+1, even on autozone.com it'll tell you that it's the correct firing order.

[97SL2guy]

I'm baffled here! I have a 99 SL2 with dohc engine. I know exactly what the firing order is SUPPOSED TO BE: 4-1-2-3. It's stated in my Haynes manual as well as on every website I've checked. BUT (THIS is the part that baffles me!): I looked at MY wires at the coils and noticed they are NOT in the correct order! Yet it's ran smooth for the 2 years since I've had the car! So something isn't right here. I guess maybe I'm confused on what order the coils fire and maybe it the plug wires ARE on correctly. But I figured the wires at the coils, looking left to right, should be inserted as #4, #1, #2, #3. Apparently NOT! Because my wires are 4-2-1-3 and it runs smooth. When I switch the two inner wires the car obviously runs like crap if at all.

So I guess my question is this: if you're looking at the coil packs, ARE the wires from left to right SUPPOSED to be 4-1-2-3 or 4-2-1-3 like they are on my car? I suppose the little numbers on the coil packs are not an indication of how the wires are supposed to be connected, but rather the order in which they fire.

Seems weird to me, but I'm leaving them how they've been since I got the car 2 years ago.

[alordofchaos]

Wires in the engine are 1-2-3-4

Connect to coil packs in 4-1-2-3

Read this post - particularly #8. Pretty sure if you have numbers written on coilpacks, someone added them. I haven't looked closely in a while but don't recall seeing numbers on the coil packs - and I cant imagine they are factory, since they can be swapped.

http://www.saturnfans.com/forums/sho...d.php?t=105567

also see the last post in that thread, firing order v wiring order. Thread title mentions firing order, but the question is really about the order in which they are wired at the coil packs

[billr]

Yeah, lots of confusion here. The firing order is 1-3-4-2. The meaning of firing order never changes, no matter what the engine type is. Cylinder numbering order or order of plug wires on a cap or coil pack varies for each specific engine type.

I say "meaning of firing order" because a specific engine type may have a different order than most in its family. Clear as mud now?

[onlinebiker]

Isn't the system utilizing wasted spark? (Plug fires on compression and exhaust stroke)?

[alordofchaos]

Yes, which is why it may run fine with certain wires switched.

You'll sometimes see it referred to as DIS (distributor-less ignition system) and waste-spark is a variation of DIS. It'll fire spark plugs in pairs, opposite to each other in firing order. Since the firing order is 1-3-4-2, it fires 1 & 4 at the same time, and 2 & 3 at the same time, which explains the coil pack order

More than you ever wanted to know
But you never know when it might come in handy
http://www.differentracing.com/tech_...n_control.html

[fetchitfido]

When I put 3.1 V6 coils on one of my DOHC's (uncommon "mod", slightly stronger spark than stock) it ran better with the plug order on the coils flipped around. 4123 is what it should have been but it ran better 1432; IIRC the 3.1 V6 coils primary and secondary windings are reversed from what the S-Series use's hence the wire order change.

There might be a part number on the coils you can cross reference to see what engine they belong on.

[97SL2guy]

Originally Posted by alordofchaos

Pretty sure if you have numbers written on coilpacks, someone added them. I haven't looked closely in a while but don't recall seeing numbers on the coil packs - and I cant imagine they are factory, since they can be swapped.

The numbers are not "written" on the coil packs, they are embossed there on both coils. Even shows those numbers on coil packs in the Haynes manual. It's meant so show the order the wires are to be connected I'm sure. But no, the numbers were NOT just "written" there. These numbers are on EVERY Saturn coil I've found at junkyards too.

This is what the coil looks like, exactly as the numbers are on both of mine.

[97SL2guy]

Also, it's like I said in my earlier comment: I know what the firing order is, and I know how the wires are SUPPOSED to be hooked to the coils, however, MINE are connected with 2 and 3 wires on the wrong posts and it runs fine, but when I switch them around to what all the manuals show, it starts chugging and popping. Something is NOT right here, but it's run smooth since I bought it 40,000 miles ago. (Until last week when it stopped starting, but that's a whole different topic). I'm still baffled at how it can run so good so long if 2 wires are on the wrong posts on the coils. But I'm leaving it how it is since it's the only way I can get it to run.

[onlinebiker]

Originally Posted by alordofchaos

Yes, which is why it may run fine with certain wires switched.

You'll sometimes see it referred to as DIS (distributor-less ignition system) and waste-spark is a variation of DIS. It'll fire spark plugs in pairs, opposite to each other in firing order. Since the firing order is 1-3-4-2, it fires 1 & 4 at the same time, and 2 & 3 at the same time, which explains the coil pack order

More than you ever wanted to know
But you never know when it might come in handy
http://www.differentracing.com/tech_...n_control.html

I thoght so. This system has been in use a long time. Many motorcycles used it - including Harley.

It is why Harley has the loping sound at idle.

If you go through the valve and ignition sequence you will find tha the #2 cylinder ( rear) is actually getting a spark ATDC of the end of the.exhaust stroke. At low rpm the air/fuel ignites before the piston starts back down. By the time it starts into the compression stroke there is almost no mixture left to burn.

Remember the cylinder timing is on a 45 degree overlap - not 180 degree.

At higher rpm the downward velocity of the piston is fast enough to create a low pressure are which extinguishes the flame. Thus there is enough mixture to make power on the compression stroke.

This can be verified two ways - 1. The rear cylinder runs cooler - because of the partially spent air/fuel load.
2. Going to two coil ignition drastically smooths the idle and increases horsepower.

Dumb stuff we learn along the way..

[alordofchaos]

Originally Posted by 97SL2guy

The numbers are not "written" on the coil packs, they are embossed there on both coils. Even shows those numbers on coil packs in the Haynes manual. It's meant so show the order the wires are to be connected I'm sure.

I thought you were saying there was only one number on each tower. I've seen several pics where someone had hand-painted in white a number on the coil packs.

Those numbers in your picture make sense and show what I was talking about - the pack can be switched, so having one number on each tower makes no sense. If the pack is on the left, you'd use the number on the left of each pair (4 and 1) and if the pack on the right side, you'd use the second number (2 and 3)

So this is how your #2 and # 3 wires run from the engine to the coil packs?
If so, I'd do what fetchitfido said and confirm they are Saturn coil packs.

[alordofchaos]

Originally Posted by fetchitfido

When I put 3.1 V6 coils on one of my DOHC's (uncommon "mod", slightly stronger spark than stock) it ran better with the plug order on the coils flipped around. 4123 is what it should have been but it ran better 1432; IIRC the 3.1 V6 coils primary and secondary windings are reversed from what the S-Series use's hence the wire order change.

There might be a part number on the coils you can cross reference to see what engine they belong on.

This mod is a new one on me. Any GM 3.1 will work, and I assume you pull the first two packs only? Might be interesting to try sometime. Did you see any benefit from the mod?

[alordofchaos]

Originally Posted by onlinebiker

I thoght so. This system has been in use a long time. Many motorcycles used it - including Harley.

It is why Harley has the loping sound at idle.

If you go through the valve and ignition sequence you will find tha the #2 cylinder ( rear) is actually getting a spark ATDC of the end of the.exhaust stroke. At low rpm the air/fuel ignites before the piston starts back down. By the time it starts into the compression stroke there is almost no mixture left to burn.

Remember the cylinder timing is on a 45 degree overlap - not 180 degree.

At higher rpm the downward velocity of the piston is fast enough to create a low pressure are which extinguishes the flame. Thus there is enough mixture to make power on the compression stroke.

This can be verified two ways - 1. The rear cylinder runs cooler - because of the partially spent air/fuel load.
2. Going to two coil ignition drastically smooths the idle and increases horsepower.

Dumb stuff we learn along the way..

Neat info, thanks!
The more you know . . .

[fetchitfido]

Originally Posted by alordofchaos

This mod is a new one on me. Any GM 3.1 will work, and I assume you pull the first two packs only? Might be interesting to try sometime. Did you see any benefit from the mod?

All 3 are identical other than having cylinders 5 & 6 added to the labeling mix. I'd suggest whichever 2 call out 5 & 6 just to give the next person to work on it something to think about

I'm not sure it helped any, certainly not enough to be worth buying unless you currently have a verified bad coil. I don't remember which car I did it to anyway, was either the '93 SL2 that got every mod short of a PCM tune or an otherwise stock '96 SC2 that got higher than expected MPG.
I believe all GM 60º V6 coils are the same so they don't have to come from the 3.1, those were just what my dad had a stash of at the time for his Cavalier Z24.

[alordofchaos]

OK, thanks - will try and remember that if they go bad. I think most people said that spark improvements generally didn't do much but a few swore by their upgraded systems (using the butt dyno, IIRC )