Firing Order for the 3.1 ltr

[GM6341]

Well here's one that's got me stumped. My son's 1991 RS has a rebuilt engine in it and instead of the 1-2-3-4-5-6 firing order that's supposed to be right it has 1-4-3-6-2-5. I believe this is the Lumina Euro Coupe engine from Mex. Anybody know for sure?

[Shortbus]

Can you see any of the block casting numbers on the engine?

[1992RS]

That's right GM6341. That 3.1 was kinga screwy. I said the same thing when I looked at the firing order. But the cylinders are numberd funny. You have 1-3 on the left and 4-6 on the right instead of alternating with 1 3 5 then 2 4 6 on the other side.

[GM6341]

Originally Posted by John

Can you see any of the block casting numbers on the engine?

John, at this point I haven't had a chance to really look as my work has kept me from having the time. If I get a chance tonight I'm going to see if I can get to them. The brackets that hold all of the junk on the front of the motor make it hard to see. I'll let you know as soon as I get them.

[GM6341]

Originally Posted by 1992RS

That's right GM6341. That 3.1 was kinga screwy. I said the same thing when I looked at the firing order. But the cylinders are numberd funny. You have 1-3 on the left and 4-6 on the right instead of alternating with 1 3 5 then 2 4 6 on the other side.

After giving it some thought, you're probably right. I'll double check a couple of things and let you know for sure, like the casting number. The really funny part is that the two local dealers plus the GM customer service line didn't know. They even sent me the GM firing order sheet and it didn't show the right motor. I'll let you know what I come up with.