combustion problems - HELP

[cobra_2_76]

I have a problem I just can't figure out. I'm getting fuel to and though the carb, floats ok, 66 primary jets, 68 in secondary. Idle screws about 1 turn out. I'm getting spark to the cap and plugs, verified MSD box works fine. No fuel filter obstructions.

But it won't run. I can get it started once and awhile if I turn the dist to about 30 degrees advanced, but if I return it back towards 10 degrees it dies, and becomes harder to start. It also appears to be harder to start when warm.

This engine ran really nice up to about two weeks ago when I noticed a slight miss or something when driving it at 60 mph, just barely noticeable. Mechanic who was checking my drive shaft balance didn't notice any problems. Over the next week it progressively got worse... until it wouldn't start unless I started advancing the distributor as noted above.

Originally I thought I had a broken coil wire to the horseshoe connector, so I replaced it with a new one. Didn't solve the problem.

Replaced the plugs, cap and rotor, just in case something was amiss there but again no difference.

Any suggestions......one thought I had was whether the carb is passing too much fuel, maybe a cracked carb body? Crack worsend over couple weeks? Would that explain why it might run 30 degrees advanced? (advance gives the engine time to burn the fuel but at 10 degrees floods out?)

I'm open to any ideas

Other particulars:
9.0 compression
351W heads
Blueprinted Duraspark by Accel
MSD 6AL box
Mild cam
about 8,000 miles on engine
does not burn oil or consume fluids
17 inches vaccum
Edelbrock Performer manifold
Holley 600 4150
Holley mechanical fuel pump

 

[HISSIN50]

im not that good with carbs. if none of the old timers in here know, might try posting in the classic section - those guys should be really up on carb settings/troubles.

im alright, but a lot of it is trial and error - im not smart enough to know what i need to have it dialed in the first time.

good luck.

 

[Michael Yount]

If you're sure you're getting fuel into the cylinder in reasonably proper amounts, and you're certain you're getting spark at the plugs - but it won't run, then you're not getting the spark at the right time, or your valve timing is off. Chase the timing/dist. cap wire order. Not sure what else you changed - are you sure your cam timing is correct? Was that altered (new cam?)?

 

[HISSIN50]

oops, i went to sleep on this one; i confused the threads. i thought Cobra 2 was the one who posted about his jetting being messed up (no/low fuel into the furthest intake runners). i dont know how i posted my first reply to this thread - i think knowing how to read would help.
disregard what i posted above (and this one, for that matter).

 

[Michael Yount]

In the words of Emily Latilla of Sat. Night Live fame (played by Gilda Radner) - "Oh, that's very different. Never mind."

 

[HISSIN50]

In the words of Emily Latilla of Sat. Night Live fame (played by Gilda Radner) - "Oh, that's very different. Never mind."

LOL. could not have said it better myself - but if i did, i would probably post it in the wrong thread.