1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

need help with timing and carb

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Old 02-27-04, 09:01 AM
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the rxzero

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need help with timing and carb

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?

Last edited by rotorysuzuki; 02-27-04 at 09:03 AM.
Old 02-27-04, 09:22 AM
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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?
Old 02-27-04, 09:32 AM
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the rxzero

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yes it also has mech. secondarys i put the smallest squirter i could get in
Old 02-27-04, 09:46 AM
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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??????
Old 02-27-04, 09:56 AM
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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
Old 02-27-04, 10:03 AM
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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
Old 02-27-04, 10:19 AM
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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
Old 02-27-04, 10:39 AM
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Originally posted by Rx7carl
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??????
Friggin show off.

Old 02-27-04, 10:50 AM
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shoulda got a sterling/carl nikki :P: everyone seems to have problems with these out of box carbs on rotaries. :/
Old 02-27-04, 01:58 PM
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that doesnt help me I had the intake allredy and carb was 190 and I am very impatient
Old 02-27-04, 02:38 PM
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have you advanced the timing or retarded it?? have you considered the accelerator pump?
Old 02-27-04, 03:09 PM
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I have tried alot of different timing but havent done anything with the accelerator pump
Old 02-27-04, 03:13 PM
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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
Old 02-27-04, 05:24 PM
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Can you undo the mech secondaries and revert it back to vacuum?
Old 02-27-04, 07:31 PM
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maybe they sell a kit for it but I thought that mech seconds were a good thing arent they?
Old 02-29-04, 08:14 AM
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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
Old 02-29-04, 11:16 AM
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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?
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