I got a holley street avenger for my 2v Cleveland and when the car is not fully warmed up it will nearly stall when taking off from a stop, it also backfires at higher rpm. What could be causing this?

 

What size Holley is it, when I got my street avenger I had to go up in jets. If it is the 670CFM then the primarys are 68s and the secondarys are 70s I believe. Try going up to 70 pri. 72 sec. and see if that helps.

 

Same problem I had yesterday. We replaced spark plug wires, rotor and cap, and spark plugs. Did the trick.

Or you can replace your power valve in your carb or do a full rebuild on your carb.

Also check timing...

 

its a 670, I put the timing back to stock timing but it didnt help much, should I retard or advance them?

 

for the ignition:
1. put back to stock (something like 8degr BTDC).
make sure to disconnect the hose going to the vacuum advance at distributor and bloc the hose while you measure up initial idle advance.
2. still with vacuum advance disconnected rev the engine up slowly
check on the timing how far it advances.
Does it still misfire ?
if not, then maybe you had the vac advance hooked up to manifold vacuum instead of ported vacuum

 

+1, timing or vacuum advance. Also a cracked cap may do this or the wrong firing order. I'm with kalli. Check the timing and vacuum.

 

Sounds kind of like a lean stumble and then lean up top... I would pull the plugs and see if they were white. Also, those are vacuum secondary carbs, maybe the vacuum spring is too heavy and not opening the secondaries soon enough or all the way.

 

my current distrubitor does not have a vacume advance, could that be the problem?

Should I pick up a distributor with one?

 

I am thinking lean as well,, is it possible that your fuel filter might be plugged or that a fuel line might be kinked?

If your dizzy does not have a vac advance you won't need one. You dizzy should make up the difference on themechanical advance side. No vacuum advance might require some adjustment to the initial timing setting though...

 

put it that way:
if you don't have vacuum advance and your initial timing is at ~8 degrees, then ignition is most likely not your problem anymore.
distributors without vacuum advance are sold as racing distributors. This means: always full open throttle. the vacuum advance is helping in street conditions. better drivability for let's say little throttle up hill. will save petrol when cruising... etc.
so if you're not flat out racing a distributor with a vac advance will make for a better driver.
BUT: the car should run with no problems even without vac advance. i was driving one year without one.
I still cannot say what exactly the problem is. I don't know much about carbs, but as for ignition, try as well as stated before:
check the total advance when revving at ~2500. how much is it ?
was it running fine before you changed the carb ?