ElkySS

iTrader: (6)

i replaced my head gaskets with impala ss gaskets and had my buddy do some light porting to the heads while they wer off. (i had them checked out and was told he did a good job). now there is a small, inconsistent back fire out the exhaust. i figured it was just in need of a tune and the computer trying to learn it but i thought id make sure by making this thread.

My95Z

iTrader: (8)

The CR change shouldn't be enough to really make it run poorly unless you already had bad gas in it. Did you have the heads milled while they were off?

I would start by checking/rechecking all the plug wires to the opti, making sure none are reversed. Another thing that can cause a small backfire is if one of the valves are not closing all the way (if they were adjusted too tight via the rocker arms).

riceburnerZ28

iTrader: (20)

you might wanna adjust your valves, check your ignition wires and plugs for fouling or burns. Check for any codes too.

ElkySS

iTrader: (6)

no codes and it only really does it when it wants to. maybe one a minute. otherwise it runs smoother than before

ElkySS

iTrader: (6)

the rockers are actually a little looser that they wer before right now.

ElkySS

iTrader: (6)

ok how do you guys set the rockers while its running? what i did was i tightened them until they stopped chattering then turned it a total of a 1/4 more. iv heard go a 1/4 iv also heard to go 1/2. which one works best for you guys?

riceburnerZ28

iTrader: (20)

I've found 1/4 turn to be a bit loose. Half turn is all you need !

ElkySS

iTrader: (6)

yea im trying to re adjust them. and im going a 1/2 turn i think this might be partially the bad tune thats on it. its just a base tune for the cam

ElkySS

iTrader: (6)

number 8 and 6 spark plug wires wer switched thnx