Setting Curb Idle Speed of Carburetor Video -Holley Carb DVD

[thizztian209]

I need a fedback on my 84 305 chevy...I run of gas and I put gas and I try to start it and all it do is just keep on crankin...idk if overflow coz of I keep pump it..and I wait til next the next to start it about to fire up but after that it just keep on crankin again...wut shud I do?I love my chevy....

[kellzsanator]

ok, heres one for you. i just made an intake manifold for my porsche 911 (1980) and put a holley 4 barrel truck avenger carb on top of it. I fugure, if wont be too big because the secondaries will only open up when the engine demands for it (vacuum secondaries).

i have had the idle screw for the throttle position all the way unscrewed, but

but i have an idle problem: it idles to high, like 3k rpms.

[kellzsanator]

@kellzsanator so i have been playing with the other smaller throttle position screw next to the electric choke. it will be idling at 3k rpms, and when i turn that screw to close the throttle and i start the engine up again, it will start up and the rpms will fall all the way down until the engine dies.

maybe its just the porsche engines need a very fine tune amount of air at the idle, that i have to keep trying to hit, but could it be something else?

[kellzsanator]

@kellzsanator i am now trying my last idea which is closing the primary throttles at the idle adn adjusting the other screw to open the secondaries some, to the flow will be even through the two sets of throttles.

maybe this will help?

thanks

scott

[splinter196]

also i have a tickover when not in drive of near 2000 rpm but about 700 in drive any one know if this is somthi i can do somthin about if i lower it car stalls i do have stage two cam in it dont know anyone playing with these engines in the uk

[splinter196]

i have a secondary vac carb got a new set of adjustment springs as they seemed not to be workin took it apart and the hole was blocked by the gue they had assembled it with from new i can see my carb as im driving as its a t bucket goes better now dropped to purple spring will try next one down to see if better still backfire on overun now gone wuhoo it is a 390 carb on bored out 231 buick odd fire bottom end with even fire turbo heads

[grngs1]

My car is overheating with the holley carb, can i adjust it using the mixture screws?

[BoxWrench]

@grngs1 most likely, your overheat problem has nothing to do with the mixture settings of your carb.

First thing to check is that your plugs are wired correctly and then verify that your timing is set right. Timing should be in the ball-park of 6 to 12 degrees Before Top Dead Center.

After that is verified, check your water level, and be sure that fan is operating correctly and has an operational fan shroud.

Did you recently change water pump or anything related to fan and or cooling system?

[johnnypneumonic]

@BoxWrench If its really lean, it will get hot. The more heavy the mixture, the cooler the engine.

[TheIntolerantAtheist]

If I stop wrong my engine shakes, if I stick my car into "park" it sometimes shakes violently, the engine sounds weak and feels like it's going to stall but never does. If my battery is disconnected for any length of time it's even worse, the engine will just "click off," one moment it's on the next I notice the car isn't running, always at stop lights with the "battery" icon displayed after stopping weird. Shops can't duplicate the problem. Could this be an idle timing problem?

[TedJankowski]

OK, What if the Idle screw is backed all the way off and it's still too high of an idle?

[BoxWrench]

@TedJankowski There is a single Idle "Speed" screw that contacts the throttle arm directly. There are two primary Idle "mixture" screws, one on either side of the front/primary fuel bowl.

If you have the idle 'speed' screw backed out all the way, and the idle 'mixture' screws are somewhere in the neighborhood of around 1 turn backed out each, and your idle is still too high... you need to check your timing first and then your floats after that.

Our Holley DVD covers all this in detail...

[Schectersch1]

Would a fast idle and a hard cold start [without the choke sticking] be something that can be fixed by turning the idle speed screw out and the mixture screws in?

[BoxWrench]

@Schectersch1 First verify that you have decent compression in the cylinders, that a decent spark is being created and that your spark plugs are in ok shape, then you can begin to troubleshoot the carburetor tuning.

The basics are to set idle in gear (friend holds foot on break to stop vehicle) with a vacuum distrib hole plug it at the carb fitting. Then yes, out on idle screws and in a touch on speed screw. The detailed version of how to do this is in our Holley DVD at our BoxWrench site.

[bkselect]

do you turn the screw while the car's going or turned off?

[BoxWrench]

Definitely not while the 'car' is going, it'd be to hard to run along side the car driving down the street... ha ha

Yes, you would make the adjustments while the engine is running. At :30 in this video it says to "start the engine and let it warm up...".

This video is only for adjusting the "idle speed screw" it does not cover the idle mixture screws which are the first part of the adjustment.

Our Holley DVD has dozens of other adjustment and tuning methods in a 2 1/2 hour DVD.

[bkselect]

yeah. is holley carby similar to toyota 1982ish carby engines? coz i just got a 82 dx corolla with 4k and want to work on it but i don't know shit all about cars. aw got so much to learn haha.

[jamesmiltoncox]

While it is going, but if its an auto you need either another person to hold the brake while it is in drive and adjust, or put it in drive yourself with your foot on the brake, note the rpm, put it back in park, adjust, then put it in drive and check it again. This is because the idle in a car with an auto trans is set with it stationary in drive. Hope that helps, make sure you adjust the idle mixture too.

[SkylineR034]

Nope, the engine has to be running.

[crazycrowd818]

man, i love your videos! how different is a holley compared to a demon carb? (apart from the 4 corner screws)

any tuning tips on those?

Thanks.

[BoxWrench]

Barry Grant carbs are basically a knock-off of Holley carbs...

You can use almost all of the content in the complete DVD for the Demon carbs. Same principals and extremely similar designs, inside and out.

[TClear4]

thanks!