Ok so i fianlly got the truck running solid...i ended up having to ditch the holley and just scooped up an Edelbrock and the truck runs a lot better...as for the timing issue, i was hitting it with the timing light and was adjusting it to the mark at 10 degrees btdc and was getting some crazy miss firing, well it appears that maybe the timing chain has jumped a tooth because i adjusted the timing by ear and fixed the miss fire but when i hit it with the light the timing mark is way off. so i guess its time for a new timing set!

 

Sorry to hear about the timing set. Its a pain but your symptoms point towards it. After changing it out, at least your truck will run like a champ!

Eric

 

im in a similar situation. carb is a new 670 cfm holley and im getting back fires, stalls and hesitation when i hit the gas. is that just the carb dumping too much fuel into the engine or a timing issue?

 

Did you ever check the balancer?

 

That would be a lean condition or overly advanced timing. Sounds like you need to get a set of accelerator pump cams, though.

Holley 20-12 Holley Accelerator Pump Cam Assortment

 

hah i guess i didn't explain very well. its back firing out of the tail pipe. my apologies.

 

Sounds like it is moving forward for you, but for future reference, always verify firing order first, making sure that #1 plug wire is on #1 on the cap. You can chase timing issues all the way across town and back but if that is wrong, you will never catch it.

 

Thats exactly what i was getting out of my rebuilt holley! I had a crap load of black smoke, even fuel dumping out of the tail pipe, so thats when i figured it was the carb, after screwing with the holley i think i figured it was one of 3 things. 1st the fuel level in the bowls...when adjusting them make sure your at idle and take out the plug on the side of each bowl, 1 at a time and then adjust fuel level by losening the tope screw and lock nut, turn it in to lower, and out to raise, you want the fuel to come out of the side at just a trickle, then tighten the top back up.
2nd the fuel drip on the bottem of the main bowl. The is a small bb that is held in by a retainer that can get stuck open so clean it and make sure the gap between the retainer and bb are within specs, if its to much everytime you press the gass you will be dumping fuel into your carb
Last was the aecondary meterind body...i do t have much advice there just make sure it clean and all the "channels" for fuel are free of debris
I never pinned it on one thing but thats what i think was the problem. Hope it helps, and make sure the firing order is right, and if anything do like i did and adjust timing by sound until you dont here the miss fire anymore

 

I should add that i think whoever owned the truck before me replaced the timing set and i am thinking that when it was installed they disnt put the 1 cyl at tdc on the compression stroke, which means it was tdc on the exhaust stroke which would cause the timing to be way off as well

 

Yeah that could be a problem. You might pull a valve cover on #1 and see if anything looks off like if you are getting valve lift on the compression stroke or power stroke.