(Sorry for spelling)
As the tittle states
69 camaro ss 350(not orig eng)
trickflow heads 23° , performer rpm intake, edel carb 600cfm("almost" no big enof but it works), summit cam **06 if i recall right...th400 tranny

Car was doing great untill a day or so after i changed coils(ran fine right after) but as the car dosent see above 4k rpm for casual driving(and thats still high for casual).. I used to run it to 6k w/o a prob pulling great at 4.5k+.

Runns alright(not best, prob just tunning problems iv been having) untill it hits 5k +/- a few and it just stops and goes nuts, backfiring, knocking, just crazy.

Tried all the things i could think off..
Fuel/air fillter, happens at any timming i set the engine(tried a wide range), new plugs, went back to the stock coil(first thing), new points and rotor, new wires, many diff jettings on the carb, all rockers lashed right.

What boggles my mind is that it started out of nowere, and it does it basicly at the same point ever time....sometimes diff spots for diff timmining settings. Even noticed it happen in neutral(know i shouldent be that high in neutral, only happened once =p)

Any help/opinuns would be welcome

Beers

A bad condensor can cause it.

Check the resistor as well. The coil you had may or may not of had a resistor built into it, or new one may have one built into it and your doubling the resistance to the system and cutting voltage. If you had the resister type coil before and then installed a coil without it and there is no resistor on the firewall. its likely that you just ran 12v to your coil and consequently fried your points.

Try a new set of spark plugs, preferredly Autolite's right after you check for broken valve springs.

Is the new point set heavy duty, ie, 28-32 oz pull? Purchase a point set with a stiffer spring, point bounce is eminent at high rpm's.

The new coil had came with a resistor mounted to it, but i dident wire it in as i ran it throught the ressistor for the old coil that was on the firewall.
No broken springs as i had the valve covers off lastnight when changing headers, also pulled out all plugs at that time and changed with another set.
Points were first thing i changed after i put the stock coil back on, even tho the old ones dident seem to be bad(they werent to old)..

Condensor i dident do though, beleave i have one lying around and will try tomorrow and report.

its likely that you just ran 12v to your coil and consequently fried your points.

I am by no means an expert, but i thought it was points>coil>rotar/cap....am i missing why if i did overpower the coil it would fry the ponts.

Thanks

When an engine is cold upon start-up, it needs a full 12 volts to the primary to generate a large spark to fire. This is why there is a yellow wire from the starter solenoid bypassing the resistor, or resistive wire, to the pos side terminal of the coil.

As the engine warms up, less spark is needed to run the engine. So, with either a resistor or resistive wire, as current runs through the resistance, the resistance heats up and reduces available voltage to the coil. This reduced voltage also reduces the arcing across the contacts and extends the point life by not building up point resistance and reducing contact shape.

If full voltage is always across the point set, the contacts themselves don't live long due to the increased current load. Plus the fact the coil will be very hot to the touch after 15-20 minutes of run time.

By design, ignition coils are really 6 volt coils. If you get a chance to look at a 6 volt electrical system, Ford 8N tractors, older farm tractors and anything built before '54 and earlier, you will see no resistance for the ignition coil. After '55, and the induction of 12 volt systems, primary coil resistance came into existence.

A friend of mine had the same problem and found out that the cam lobes flatten. Checking valve lash won't detect the problem since you're following the now flattened lobe. See if you can eyeball measure the lift of each lobe as you hand spin the motor.
Good luck.
Ken

I once had a problem with me Elcamino , it turned out to be in the trans

this sounds extremely obvious, but if you have the coil wired backwards (+/- switched), it will act very similar. it will run but not rev. simple but check it out, i've seen it before.
good luck

Dident have time to mess with it today as i burned throught a powerstearing line today(dident pay full attn when putting new headers on, gg me) and spent my evening cleaning up that mess, will try some things tomorrow if i get the time.

As far as coil wired backwords and flattened cam...The car still performes /runs for the most part great untill i fit in the near range of 5k, and if thos were the problem wouldent it effect a much wider rpm range? If i leave it to auto shift at 4k chance are no one would know at all(still need to reset my shift points high some day)

Understand on the need of the ressistor and one is conected, i may check its voltage anyway to make sure its working properly.

Any way it could possably be vacume timming ect kicking in/out to much at a certen point?

Thanks for the insitefullness(sp)

Seems i lied on first post, was changing timming each way be feal a little bit...Dug out the timming light and hooked it up, and w/o the vac advance hooked up, and it was reading way way high, brought it back down to around 10°(had to screw in my idle screw to make it keep running).

Anyway it now makes the problem happen around 4300-4500'ish...So it would seam to my limmited knoledge that it is directly related to timming. Does the symptoms seems like what would happen in my case though? not vacume advancing proberly cousing this?

Dident drive it to much after adjusting timing, a few small runups, but came back fast as no power stearing atm is a pain.

Vacuum advance only has an affect at idle. 68RS406 has some good advice, but it doesn't sound like you checked it. A coil wired backwards will still spark but the spark will be weaker. Under higher cylinder pressures it could misfire. What happened with the condensor, did you change it?

just went out and checked coil and its wired right, changed condensor and it dident make a difference. :(

Have you checked the weights out and see that they move open and close without a huge amount of force against the springs?
Recheck dwell and plug gaps. Look at point contacts and check that they aren't pitted.

not sure how there supposed to feel but ill check weights see what i can tell, points still looked good when i was changing condensor, as they are fairly new also but will glance agian while in there...may have an extra at work. plugs and dwell should be set to what?(10.4 comp i beleave, matters for plugs?). *think* when i checked them befor putting them in they were .040?

Point Gap @.019"
Dwell @ 32deg.

Plug gap should be .35. I know MSD says you can go larger, but in my experience with that, it wasnt pretty. The performance lags badly.. I reset mine back to the .35 and it was much better. :)

My first thought on this was fouled plugs as it has always been the crack and pop at higher rpms for me. But you say you have changed plugs. I have also seen a bad coil wire do this. As well as a spark comming thru the coil wire boot and jumping to the coil terminals.
How about the total timing? Shine the timing light on the mark and rev the motor up and see what you are getting. Maybe you need an ajustable vac. advance.

Threw in new points and set gap on them, plugs were .36.. Coil wire was changed when i did the other wires after the problem, so was before and after, not that sadly.

Threw on timming light and reved the engine(much to my neibors dislike) with vac advanced hooked up in went up and past straight up...w/o vac hooked up, it rised almost 2 inches, or a little over half as much as with vacume(although started lower of course.

I can wrench on a car all day, but as im clearly not to good at the tunning, and the ignition part i dont know what to make of it.

How was the car on the road with the new points and gapped plugs? Form the sounds of your "straight up" on the harmonic. that sounds like its about the 32 - 36 total advance range. Though at 4k I would have though it would have been something closer to 45 or more.

Post been dead, but thought id just say finnaly got new distributer in there(wanted to ditch points setup anyway) and it took away the problem, runs great and strong.

Thanks for the imputs from all yas :beers:

sounds like your old points distributor seen its last days.

Im inclined to think that the cam lobes on the dist. shaft are well worn.
OR
the points are bad (points will deteriorate faster when using aftermarket coils)
also another thing to check is the dist rotor phasing.
In my opionion I would opt for a new distributor and get rid of the points.
Mallory makes a unilite dist. that is the same size and is electronic.