Firing Order

[lochenjons]

I just relaced the cap and rotor on my '77 k5 350 (not original engine, Ill have to look up the casting numbers , carb is '74 tho), with electronic ignition. It wasnt running right afterwards (it would idle fine, but would die if I gave it gas) so I checked the firing order in the Haynes manual. And mine was no where near what it said or the order on my buddys '78 k5 with the same distrubitor and close to same engine. I eventually too everything apart and put it back togethor and put the firing order back to where it was originally (go figure) and it works. But is this even close to being right? I mean I know if it works it works but is this wrong?

Dizzy
6 3
1 2
7 8
4 5
front

 

[4X4HIGH]

The firing order is 1-8-4-3-6-5-7-2 in a clockwise rotation. Bring the engine up to TDC of the compression stroke and where ever the rotor points is where you start with the #1 wire then clockwise as i stated.

 

[lochenjons]

The firing order is 1-8-4-3-6-5-7-2 in a clockwise rotation. Bring the engine up to TDC of the compression stroke and where ever the rotor points is where you start with the #1 wire then clockwise as i stated.

I think thats the order the manual said, I just used what they said was 1 on the dizzy, I didnt find TDC or anything and that didnt work.
It said this too:
7 8
5 6
4 3
2 1
Or something close to that, shouldnt that work with mine? Its even a nice pattern and everything, mine looks completely random.

And I cant see why it would be different between my 77 and my friends 78. Also I looked up the casting number on the block (3970010 btw) and it has a very general year list (69-80 i beleive), I know the date is stamped somewhere on the block but where?

 

[broncoman6524]

alright the firing order is like this as 4x4 posted do as he said

and as far as the block goes its like this
8 7
6 5
4 3
2 1
front

 

[4X4HIGH]

alright the firing order is like this as 4x4 posted do as he said

and as far as the block goes its like this
8 7
6 5
4 3
2 1
front

What he had posted was what he believed his firing order arrangement to be on the cap, not the cylinder numbers.

 

[4X4HIGH]

Pull the #1 plug out (driver side front plug). Have someone help you at this point, put your finger over the plug hole and have someone tap the engine over slowly until you feel your finger get pushed away then stop "tapping" the engine. Now you need to carefully turn the engine over by hand until the timing mark lines up with the TDC mark on your timing pointer. Now pull the distributor cap and find where the rotor is pointing and install your number 1 wire at this location then continue with a clockwise rotation of 1-8-4-3-6-5-7-2

Keep in mind that someone in the past may have pulled the distributor out and did not reinstall it in the factory location as your book might say.

Your distributor cap should look something like this when you're done.

..5...7
6........2
3........1
..4....8

Front of engine

 

[ryoken]

I think thats the order the manual said, I just used what they said was 1 on the dizzy, I didnt find TDC or anything and that didnt work.
It said this too:
7 8
5 6
4 3
2 1
Or something close to that, shouldnt that work with mine? Its even a nice pattern and everything, mine looks completely random.

And I cant see why it would be different between my 77 and my friends 78. Also I looked up the casting number on the block (3970010 btw) and it has a very general year list (69-80 i beleive), I know the date is stamped somewhere on the block but where?

A chevy, is a chevy when it comes to firing order...

I'm gonna write a book on dizzy's, it'll make a fortune.. The #1 thing people mess up and don't understand..

Follow Scott's instructions..

 

[lochenjons]

Ok I got it working! Apparently 8 and 1 had been swtiched around (before I even started to mess with the cap and rotor) and then I was confused because on my truck #1 on the dizzy starts way in the back for whatever reason and not in the front. If I'd bothered to find TDC and all that I would have realized that sooner but oh well it works and better than it ever has. It still backfires (the reason I changed the cap/ rotor to begin with) but not quite as bad it seems. So next I guess Ill tighten down the lifters/valves/ rockers/ whatever it is. thanks guys!

EDIT: It stil surges at idle too, but again, not as nearly bad. I'm guessing vacuum leak but I've looked and looked and sprayed carb cleaner all over everywhere again and again so I'm not sure where its coming from if it is