Holley Truck Avenger help needed

[NewUser]

when i built the motor in my 77 i put a brand new 670 Truck Avenger on it

when driving it if i give it more than half throttle it starts missing real bad and puffs black smoke plus you can smell it richen up like instantly


if i gradually ease into it it doesnt do it and runs fine

if i romp it and open the secondaries it doesnt do it

this is a new carb not one of the ones that they had casting issues with i have changed the accelerator pump cam to the blue one like recommended with no change

its driving me nuts and im afraid to take my kids out in it because of the fumes from the exhaust

any and all help is appreciated

Keith

 

[Disciples Performance]

needs to be tuned and dialed in, sounds like its flooding itself ive found the holley truck avengers to be very touchy especially outta the box, def not a throw it on and go setup like the edelbrocks did it come with a manual on a cd cause that should give you the tuning tips and troubleshoot on it for sure if not hit up holleys website it should have one for ya there bud

 

[rcamacho]

I'd start with the basics - check for vacuum leaks, set float level, check fuel press <6.5lbs. After that, figure out where in the carb circuits you are when it goes rich and at what HG. Then start taking fuel out of that circuit or delaying the power valve if appropriate.

A note on the Truck Avengers, there is no emulsion in the main circuit and a check valve to overcome so be a bit cautious about how much main jet you take out - it could delay or prevent the mains from starting. Also, the idle feed circuit is very long in these carburetors in order to compensate for the main start up lag. So, you actually may be on the idle feed restrictions most of the time.

 

[VegasBruce]

Here is a good article on the TA carb.

http://www.4x4mecca.com/forum/vbarticles.php?do=article&articleid=12

 

[GsxrMike]

Are you sure your advance curve on your timing is good? I had a truck doing very similar things and it was timing and not the carb. I swore it was the carb at the time.

 

[NewUser]

i drove it today to go look at another K5 and i noticed it really only does it when under a load(going uphill, passing another car) if i push down a little more on the gas it kicks down to passing gear and clears up til i let off of it and let it shift into drive