i'll start by giving my parts list...

CC306
26918-16 Beehives
10*retainers and locks
manley 7.1" pushrods
COMP1.6 pro-mag roller rockers
full gasket set
all new vacuum lines
Madtuner tune (MadZ28)

my problem is this: put it all together, went through the break in process and then took it for a ride, ran really awesome! brought it home and sat at idle in the driveway for a couple minutes. got in and it idled down and died. really hard to refire and long story short the #1 exhaust spring broke. so i got another set of springs and put it all back together.

start it up and it runs almost as crappy as it did with the busted spring but i have no broken springs, i just replaced the O2 sensors, and it just runs rich and stumbles and has the typical machine gun like sound when you mash the go pedal.

The broken spring didn't bend the valve as i could lift it all the way and spin it around without feeling any abnormality. any ideas??

 

another thing... could it be a timing issue?

 

pull the plugs and see if the are fouled, and not just from the cyl that had the broken spring, but you will want to look at that one closely for anythign that looks like debris from P/V contact when the spring broke. Normally when a spring breaks, even at idle, there is a lot of damage in that cyl. I have seen it personally on a of my few friends cars, brand new engines, going through breakin, pop a spring and we had to pull the motor again within a few weeks...

Not trying to discourage you, just telling you what to look for...

 

Do a leak down test on that cylinder.

If you hear air coming out the header or TB, you have a bent valve.

Lloyd

 

replaced the plugs along with the O2 sensors and it ran ok until i got out of the subdivision and immediately started missing, not constantly, just intermittently missing. like the plugs fouled out immediately or something?

on the leakdown test all i could hear was air going past the rings, not much but since it is an older engine it has a little blow by. none out the exhaust valve.

I checked for vacuum leaks and couldn't come up with any...

any more ideas?

 

1slowformula... what did those engines run like after the broken spring?

 

they ran like they had a miss, and were noisier then before the spring broke. sometimes stalling. When we pulled the plug on that cyl there were fragments of crap imbedded into it, from the P/V contact...

 

turned out a spark plug wire was shorting out on a header somehow... its always so simple yet so difficult at the same time. thanks for the help!

 

Glad it all worked out...