carb issues??

[69dodgedart360]

hey ppl, i have a holley street avenger 670 on my 360 and it doesnt do it too often when im going around town but mainly coming off the freeway from turning 2500rpm to a red light (oil pressure is at 30lbs, temp is at 185 nothing out of the ordinary) if i start to give it gas after i just came off the freeway the car damn near shuts off unless i floor it or let off and gas it quickly. Same thing happens if im just cruising and i stand on the gas it bogs for a second and goes. i have to result to manually shifting it just to get it going so that it doesnt turn off. Any ideas??? i think its my carb that needs adjusting but it doesnt seem like i can just get this thing right no matter what i do i.e. too lean, too rich. im thinking buy a new carb i was looking at the edelbrock thunder avs or a double pumper whats everyone else running?

p.s. already checked the timing

thanks

 

[rumblefish360]

IMO, a classic case of not enuff pump shot. When you step on the gas pedal, the carb should be squirting out fuel through a nozzle in the primary barrels. There isn't enuff.

 

[sakraceng]

gooday 69dodgedart360,because it seems to do it more often after freeway
driving it could be your float level is low and as rumblefish said its not getting enough pump shot ,your power valve may need to be replaced with one next number up as that can also cause a hesitation just as you start to accelerate say to overtake moderately-ken

 

[dgc333]

I wouldn't give up on the Street Avenger. I have one on my 360 and it has been great and required no adjustments out of the box to run great.

I would go back to basics and make sure the floats are adjusted properly and that the fuel pump is supplying enough fuel. Also, make sure the accelerator pump is adjusted properly.

 

[fishy68]

It sounds like it's definetly running lean. The Avenger carbs are good carbs but like any carb when it's not adjusted or jetted right will run like crap. Like the others said go back to basics. First adjust the float level then adjust the idle mixture adjustments and then check the accellerator pump to make sure that it is spraying the instance you push the throttle. If all that doesn't cure it it probably needs bigger jets.

A buddy of mine just bought a new avenger for his chevy pickup and even though Holley claims their adjusted close right out of the box their not. We had to raise the float levels on both the front and back alot (about 2 full turns per bowl) and then readjust the idle mixture screws. I also bought one last year and it ran extremely rich in the secondaries. I pulled the bowls off to re-jet it and found they had installed the wrong secondary jets at the factory. It had 88's in a 670 carb!!! There only supposed to be 68's IIRC so it's no wonder it ran so rich.

 

[69dodgedart360]

Thanks for the quick response's, i was looking at the holley booklet and i was thinking about buying the different pump nozzle #35(.035),Power Valve size 6.5, and an accelerator pump cam, and placing the screw in the cam in position 1 reason being i read up and it said it would be a good idea since my car idles in gear at around 650 it would find that position more useful giving me a better pump shot coming off idle sound good so far???
P.S. i think i have a vaccum leak coming from the Metering Plate in the carb im sure a new gasket would do the fix but would the leak cause related problems?

Thanks rumblefish,sakraceng,dgc333,fishy68