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Topic: 750 Holley DP adjustments.

in Forum: C3 Fuel, Emission Control, and Exhaust Systems


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750 Holley DP adjustments. (1/4)
 8/3/12 9:25pm
aceLifetime Member
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Ocala, FL - USA

Vette(s):
1975 coupe, Green, 4speed, T-top, 383 stroked, Hooker side pipes.


Joined: 9/14/2002
Posts: 72

Beer Anyone have some tips on adjusting a Holley 750 DP carb ? I havent tinkered with it in awhile and I noticed some things. When I'm cruzn along N mash the gas it has some hesitation. So I checked under hood when I got home and started turning screws etc. It seemed to help some. Does anyone knoe how to properly set them up, such as Idel screw adjustment, accelerator pump adjustments. Are the accelerator pumps to be adjusted with some gap between bottom of adjustment nut N spring or tight up against ? Looks like I may have to buy a Holley book, I had one but lost it in all the moves over the years. My motor is a 383 CUI with Hooker side pipes, 4spd, 3.70 gears. 
 
Thanks gang,
ACE


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Re: 750 Holley DP adjustments. (2/4)
 8/3/12 10:19pm
Adams' AppleLifetime Member
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Duncanville, TX - USA

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The accelerator pumps should be adjusted to where there is NO freeplay, but that pump lever is not actually moved..if that makes sense. You want to adjust it to where the screw just BARELY touches the pump lever arm.

Flat spots, if they are due to accelerator pump issues, can sometimes be corrected by changing the pump cam...the little nylon cam that screws on the linkage that the pump adjustment lever rides on.
At cruising speeds, the acc. pump really shouldn't be doing much anyway, but they do add a short skwert of fuel quickly, to overcome the flat spot....

hth


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Re: 750 Holley DP adjustments. (3/4)
 8/4/12 3:14am
DaveMLifetime Member
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Flanders, NJ - USA

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I had a hesitation on mine and I went up one size on the squirter and it got rid of the hesitation.
Dave


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Re: 750 Holley DP adjustments. (4/4)
 8/4/12 7:06pm
aceLifetime Member
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Ocala, FL - USA

Vette(s):
1975 coupe, Green, 4speed, T-top, 383 stroked, Hooker side pipes.


Joined: 9/14/2002
Posts: 72

Thanks for such a quick reply ! The nylon cam is it sized by color ? Also what about idel mixture screws on sides of metering blocks, R they to be like 1 1/2 turns out +- ? I need to do some tinkering this week while on vacation for sure.    Beer
 
Thanks again, ACE 


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