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-   -   holley carb issue (https://www.racingjunk.com/forums/showthread.php?t=22568)

blowenstang 12-21-2008 07:41 PM

holley carb issue
 
im not to good with the hole carb deal more into fuel injection an turbos some what knew to carb an spray
i have a holley 80 582 witch is a 750 dom with mech secondarys
it seems to spit back an pop somtimes when i stab it
no vacumm leaks
no fuel leaks getting twisted
its on a ls1 with work in a mustang
any ideas or input would be helpful

zerotolerance 12-22-2008 04:54 PM

sounds like a lean issue. how far out are your mixture screws what jets any power valves. need alittle more info to help. could be squirters too small

jmarksdragster 12-22-2008 08:22 PM

Not enough initial timing?

blowenstang 12-23-2008 06:47 AM

its on a ls1 with that 6ls kit from msd
the timimg been the same never change it from when i first tune it

Scooterz 12-23-2008 12:30 PM

The "spiiting back" tends to sound like a lean condition. I agree w/ the other post though... lets get some spec's: Jets size, PV or blocked? If PV, what size? Had a vacumn guage on it yet? Hows the float levels? Next, does it have a secondary idle adjustment? If so, no more than 1.5 turns there... that can cause hesitations/burps. Fuel mix screws... how many turns out at present? Ok, I am done w/ all the questions. Get some info & see if we can help more.

cepx111 12-24-2008 02:57 AM

More info would be nice and is needed but from what I gathered it's definetly lean. Probably needs either the pump circuit fattened up, like bigger squirters nozzles front and back and or maybe a 50cc pump kit or you just may need to go up a few jet sizes in the primaries. It's kinda hit and miss, try one thing if it doesnt work put it back the way it was and try something else.
Carbs need to be tuned to each indiviual set-up one that worked well on one motor might run like crap on yours, even if the motors are very similar.
Also you need to proof-read your posts, before you click submit, tidy things up a bit, it's very confusing the way you stated your problem especially with all the mispelled words and your shop talk, not poking at you just trying to help.
Goodluck, Cp

Scooterz 12-24-2008 12:34 PM

Good point CEPX, I have had to learn the hard way making multiple adjustments at one time. This rarely ever made any sense... as it hid the real issue even longer. I am not an expert, but he is exactly right... ONE ADJUSTMENT AT A TIME. Keep asking this forum until you get there, these guy's here helped me get my carb dialed step by step... keep diggin'

Tod74 12-24-2008 07:24 PM

I would set the idle with a vacuume gauge ,and I would choose the pv by the vacuume gauge as well..with the car in gear at idle...I think a bigger squirter would probably fix it, but it may just be a bandaid to the real issue, if that makes sense..a big squirter may dump enough fuel in there to cover up the hesitation but still may not be "correct" or optimal tune on the carb...

Completely agree with the above posters on one change at a time and most of all IF IT DIDN'T HELP PUT IT BACK BEFORE MAKING A DIFFERENT CHANGE

Just my opinion

drjohn67 01-02-2009 09:02 PM

carb
 
From the info you give definatly going lean under wide open throttle condition, ie: stabbing it. Forget the power valve or main jetting to correct this condition as they only work with the high speed curcuit, which your not on yet when it pops. You need to work on the squirters on both the secondary and primary side. They may be out of adjustment, too small or you may even need to change the nylon cams that work the pump levers. Holley has a number of them that have varying slopes that change the pumps reaction time. You can tell them apart by their colors. I do agree with the other posts though, try one thing at a time so you don't get completly lost.

itsabird 01-03-2009 04:46 AM

bigger squirters first, then tune from there, if you do not get a positive response.


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