Hey everyone, I just put a new cap, rotor and accel hei super coil on my 1985 Z28 305 TPI. now the engine doesn't idle right and back fires when i give it any gas. i'm almost positive that i crossed a couple of wires. can anyone give me a diagram of the firing order?

 

 

I (and my car) thank you vader.

 

do i have my distributor backwards or somethin cuz when i use this firing order no start.. if i use exactly opposite car starts and runs fine...

 

You probably do. my car works just fine with this firing order. do you have a hei coil?

 

You don't have to pay attention to where the #1 is in the diagram, #1 can be anywhere on the cap provided the rotor is pointing to the terminal you are using as #1 when the #1 cylinder is at TDC on the compression stroke. The important thing is the Firing ORDER: 1-8-4-3-6-5-7-2

 

yes I am using a stock HEI coil.. and I have the firing order right but my car has to turn over about 5 sec or so to start.. checked timing is @ 6 BTDC.. mine may be a fuel issue..

 

ace, I have a question for you. Where is your rotor pointing when the engine is at TDC? My 86 T/A 305 TPI has the rotor pointing at the left intake runner...and from what I'm used to with SBCs, that ain't right. But it runs, what the hey...

 

I just re-read vernw's post and realize that this is true...but typically doesn't the rotor point more toward what's dipicted in the diagram on Vader's post when its "more correct"?
My 78 Camaro is exactly that and so has every other SBC I've ever worked on....

 

If I remember right, the rotor is pointing just before the no. 1 point in the dist. My car runs perfect. It starts up almost as fast as can turn the key.

 

Mine starts and runs fine as well (for the most part...the engine is brand new....0.7 miles on it since breaking in the cam).
This is giving me a headache...to hell with it...the distributor stays where it is.

 

If it's not broke, don't fix it.

 

EXACTLY!!!!

 

if you have the plugs wires on right and you have checked the cap and rotor bug that they are right what else could cause an engine to mis fire like that and back fire through the exhuast i just chaged my wires and plugs and my 350 is not wanting to start at all. before that when it would get hot it would miss when you started it up again and sometimes be a little hard to get started. what causes this

 

The reason to do it like the diagram (and factory did) is simplicity when working on it.

If you end up with #1 being somewhere else than what the diagram shows, if you are incapable of tracing the plug wires, you'd really have no clue where the wires are supposed to be on the cap. If you pulled them off the cap without verifying which wire is which, you'd cause more work, and end up scratching your head for a bit.

Just like changing the color of wires in a wiring harness from stock...it doesn't hurt anything, except when someone unfamiliar with your "mods" has to deal with it.