labrat Posted October 31, 2001 Share Posted October 31, 2001 Well, this 327 motor has been sitting for about a year and we finally get the car running, but it's running REALLY rich on the Holley 4 bbl. Try to adjust the carb, get kinda close, but backfires out the carb (Big Fireballs!) when slamming pedal from idle, and still blows huge black smoke clouds. Off comes the Holley, on goes brand new 600 cfm Edelbrock 1406. Adjusted carb per manufacturer's specs. Idles good, runs good, but on "Slamming" the gas from idle, still huge fireballs! Is this a carb problem or in the ignition timing? This is a new carb, it was supposed to make the problem go away! Thanks Bill Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 31, 2001 Share Posted October 31, 2001 What's the static and mechanical timing like? Also, are you sure you don't have a vacuum leak? Quote Link to comment Share on other sites More sharing options...
labrat Posted October 31, 2001 Author Share Posted October 31, 2001 Well, without the vacum advance hooked up and the port blocked, it came out to 4 btdc with the harmonic balance white out mark. There are many marks on the balancer, and i don't know if this is the true tdc mark. I know it should be around 8~12, but i was unsure of the timing marks... Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 31, 2001 Share Posted October 31, 2001 You can buy a through-the-sparkplug-hole piston stop pretty cheap, as well as a degree wheel. I'd check where TRUE TDC is and mark the balancer to be sure. Quote Link to comment Share on other sites More sharing options...
labrat Posted November 1, 2001 Author Share Posted November 1, 2001 Well, figured out the correct timing mark, and made sure it was to to 8* btdc @ 1000 rpm. backfires through carb still. changed it to every position through 12* initial timing @ 1000, still happens. Tried readjusting carb. No dice. Are these numbers correct for the timing? Thanks Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted November 1, 2001 Share Posted November 1, 2001 12's minimum for my chevy builds, depending on cams I've needed more. I need 15 minimum with my current ZZ4 cam or it would spit as yours is....FWIW mine did exact same thing UNTIL (long trial period....I'd assumed if it was timing it would have corrected by 12 degrees, I was wrong) I got past 13/14 when it started to lay in......at 15/16 it just hauled ass and lit up instant Just be sure your total timing isn't exceeded as you bump in initial... Quote Link to comment Share on other sites More sharing options...
labrat Posted November 2, 2001 Author Share Posted November 2, 2001 Well, I figured it out today. As I was checking timing for the 10th time and readjusting the carb yet again, it ran out of gas. Put in 3 gals of premium, and it runs like a top! No hesitation or bog at all, and no more fireballs! It was either leaning out because it was running out of gas or it was the old gas that had been sitting in the tank. Finally got all the timing numbers and idle speed from the 68 vette 327 haynes manual. Thanks for all the help! Bill [ November 01, 2001: Message edited by: labrat ] Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted November 2, 2001 Share Posted November 2, 2001 HHHMMMM bad gas! When someone brings me a bike (I'm a MC mechanic) thats been sitting for more than a month(hot 100+ AZ summer) and it doesnt run well, I go straight for the carbs and the old gas... Thure Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted November 2, 2001 Share Posted November 2, 2001 Ohhh and my Z has two paintless spots right on top of the carbs, on the hood. Thure Quote Link to comment Share on other sites More sharing options...
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