ok here is what I have 12a holley int. holley 450 with .025 squirter blaster 2 coils my problem is it carrys on when i step on it but if I push slow on gas it will drive ok when I dump on it it backfires and runs like crap can some one help me figure it out its driving me crazy my fuel pressure is set at4.5 do I need to put in a return line?

 

Where the hell's Carl?

He knows more about Holleys than I do, but it sounds to me like you have too much pump shot.
I also don't know alot about timing, but I run mine as Paul Yaw prescribes on his site. I don't know if that will help you.

Does the 450 have a two position AP cam?

 

yes it also has mech. secondarys i put the smallest squirter i could get in

 

First off, you rigged it for mech secondaries? Why? Youll probably need a bigger squirter if you wanna go that way, and more cam duration. What cam and what position are you using? And is there still a spring in the vacuum box? Which color? You shouldnt have a problem deadhading it. Is this a rotary prepped carb? Or a plain jane out of the box carb?

And where the hell is Carl anyway??????

 

4.5 psi fuel pressure seems kind of low to me. I always used 6-7psi on my N/a's. Does the car smoke black? If not, you need more fuel,... if it smokes black, turn the fuel down until it doesnt anymore. Either that, or make an o2 bung in your header and wiband it.

Jonathan

 

no I didnt rig it for mech it comes that way its a holley 450 from summit it has a pink cam and I have tried both positions also have tried a 31 squirter and a 25 and it bogs and then revs and at high rpm breaks up with the 31 it runs better with the 25 but still cant take the pedal pushed hard I also have a 1" carb spacer sq bore on there

 

I just tried uping the fuel pressure and changed cam position with 31 squirter and if i push the pedal slow its ok till high rpm then it carrys on and if i just dump on the gas it is real crappy

 

Friggin show off.

 

shoulda got a sterling/carl nikki :P: everyone seems to have problems with these out of box carbs on rotaries. :/

 

that doesnt help me I had the intake allredy and carb was 190 and I am very impatient

 

have you advanced the timing or retarded it?? have you considered the accelerator pump?

 

I have tried alot of different timing but havent done anything with the accelerator pump

 

i had a bad diaphram in my accelerator pump and it had poor throttle response and would stutter when i jumped on it. perhaps you could give it a look. i cannot confirm though, i am a newb hollys

 

Can you undo the mech secondaries and revert it back to vacuum?

 

maybe they sell a kit for it but I thought that mech seconds were a good thing arent they?

 

I dont think I can convert it cant I make this work?I read a post on here where someone put this on and said it worked great

 

okay took out the open plenum spacer and it runs better but still sputters at high rpms any ideas how tto fix or how to adjust this carb?