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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: devildogmech on May 26, 2018, 01:17:16 pm

Title: Calling all Carburetor Guru's!!!!
Post by: devildogmech on May 26, 2018, 01:17:16 pm
Ok.... 79 C-10 with a stock 350/350 set up.

Truck is new to me. It came with a gunked up Edelbrock 1406. I tore the carb down and completely rebuilt it. After fiddling with the step up springs it ran like a champ..... For a day.

Over about 20 miles, it went from driving great, to having a little hesitation, to bogging to having a hard time staying running at stop lights, to dying on me at the busiest intersection in town.... After a minuet it started right back up and drove home, stumbling all the way.

If I throw it into park or Neutral, it smooths right out. This made me think its a Trans Issue.... I checked the fluid and the level is ok.... I haven't dropped the pan....

Now I grew up on Honda's... to me Carburetors are black voodoo magic. I rebuilt Cummins 903's in the Marines.... I know engines and Fuel Injection, but not Carb's....

Does this sound like a Carburetor problem or a Trans Problem?  I'm leaning towards a Trans issue, but hey, who knows.

TIA
William
Title: Re: Calling all Carburetor Guru's!!!!
Post by: Irish_Alley on May 26, 2018, 03:35:35 pm
could be a many things from carb, timing or vacuum issue.

i would start at the basics and check for vacuum leaks then check your timing and on my truck i set base at 12°-16° then hook the vacuum advance to manifold vacuum not ported like the emissions sticker says

ill also find you some post on the basics of timing and carbs
Title: Re: Calling all Carburetor Guru's!!!!
Post by: Irish_Alley on May 26, 2018, 03:38:49 pm
Ignition Timing for First-Generation GM V-8 Engines (http://forum.73-87chevytrucks.com/smforum/index.php?topic=32085.0)

and

A note about carburetor flow capacities (http://forum.73-87chevytrucks.com/smforum/index.php?topic=31379.0)
Title: Re: Calling all Carburetor Guru's!!!!
Post by: devildogmech on May 26, 2018, 04:39:11 pm
Well, I'm an idiot.

I went back and double checked stuff. Turns out the engine ate 2 quarts of oil in about 100 miles. I topped it up and it immediately ran better,...... If i'm LUCKY its valve seals (im not lucky) if not, its rings......

Anyone got a spare 5.3/4l60E swap laying around?
 :o