383 runnin rich!! need help

[91fullsize]

carbed 383 in my 91 rcsb is runnin so rich can even stand behind it without my eyes burning to where i cant stand it already turned the mixture screws in and backed them out 3/4 of a turn timing is set right at 14 initial 36 total exactly like lunati suggested throttle response was great at a full turn of the screws but its startin to hesitate off idle but on the 4 barrels its great i dont know what to do, quick rundown of the engine 10.5-1 383 dart heads lunati 60113 hr scat bottom air gap holley black pump with fuel pressure at 6psi at rail holley 750 street hp double pumper any other question please ask or any ideas let me know thanks guys!

[randeez]

at idle to rich? change the power valve

[91fullsize]

yes sir, very rich at idle with a haze of smoke what size powervalve comes in those out of the box and what should i go to???

[Justin_Inc]

turn the mixture screws back in! if you can turn them all in without the truck dying on you, then the PV is leaking fuel (you can also look down the carb while idling to see if fuel is dribbling out).

Start with the base of 1 turn out how you said it idled good (if you have a vac guage, this can be done by getting the highest vac reading then reset the idle speed and re-set the accelerator pump to be within .050 of full stroke @ wot). If you have tip-in hesitation, then you will have to play around with pump cams and squirter sizes.

So by doing the above, you now had an idle vac reading, you want to install a Powervalve with a rating around 1/2 of the idle vac reading while in gear. (I usually go just above half of the reading, so if its 12 at idle in gear, holley recommends 6-6.5, I use a 7.5-8 and then tune accordingly).

[dave89iroc]

turn the mixture screws back in! if you can turn them all in without the truck dying on you, then the PV is leaking fuel (you can also look down the carb while idling to see if fuel is dribbling out).

Start with the base of 1 turn out how you said it idled good (if you have a vac guage, this can be done by getting the highest vac reading then reset the idle speed and re-set the accelerator pump to be within .050 of full stroke @ wot). If you have tip-in hesitation, then you will have to play around with pump cams and squirter sizes.

So by doing the above, you now had an idle vac reading, you want to install a Powervalve with a rating around 6" lower than the idle vac reading.

very good walk through

[91fullsize]

i can turn the front screws in without affecting the idle but if i turn the back ones all the way in it tries to die it should do that with the front ones also shouldnt it??

[NEUMANNZZ]

yes.

[91fullsize]

changed the power valve and that was the problem still runnin just a tad rich but the more i play with the mixture screws the better it gets but its a whole lot better thanks guys

[NEUMANNZZ]

might have to jet down one or two jet sizes.

[91fullsize]

i was thinkin bout that also what size comes in them out of the box?

[NEUMANNZZ]

http://holley.com/data/TechService/Technical/Carb%20Numerical%20Listing.pdf

[NEUMANNZZ]

good tuning info page 3-4

http://holley.com/data/TechService/Technical/Carburetor%20Tech%20Info.pdf

[91fullsize]

kinda curious also how i could get less fuel at idle but more wide open cause it feels like its leveling off way before 6500 rpm which is what cam should make power to would the accelerator pumps have anything to do with that?? i noticed there was a 50cc upgrade kit would that be worthwhile?? thanks for ur help by the way

[NEUMANNZZ]

using bigger accelerator pump shooters(squirters) or switching out accelerator pump cams, usually found in a trick kit. if a bigger shooter doesnt work then upgrade to the bigger accelerator pump. get your jetting in order first.