holley 94s on a olds 303 HELP wont idle

i have my olds 303 running nicely now other than one thing. for the life of me i cant get it to idle no matter how much reading i do and how much searching i do on here. i will do the best to explain my issues and everything related

i am running an edelbrock 6x2 with the center 2 carbs blocked off. .50 jets and 2.5 power valves. all the carbs are rebuilt holley 94s model 59. for the life of me i cant get this thing to idle. with the trottle slightly open (enough to keep it at a nice idle) it runs great, everything about it runs great, no dead spots, no sputtering etc etc. i just cant get it to idle at all. i have played with the idle screws, fuel pressure. im getting the best results running the motor with 2.5 pounds of pressure showing at the gauge at the end of my fuel rail. screws in, out, half way, quarter turn here and there, nothing changes the idle at all. if i let go of the throttle it dies almost right away.

also. after running the motor, say about an hour. if i try to fire it up again i get nothing other than a starter spinning a motor.


i am seriously lost here and hope some of you guys can help me out. i need to drive soon!

http://www.youtube.com/watch?v=R-hg4Y20aIo

 

Check your intake gaskets,i had the same problem,the ports are smaller in height.There are two differant sizes.

 

intake gaskets are good.

 

Are you positive there are no vacuum leaks in the intake manifold or carbs?

 

You did not say if you are adjusting the idle "speed" screws??? (not the twin mixture screws)

In the vid, it seems to be able to idle low enough to not expect intake leaks. But in the vid, it just seems like the idle speed screws need turning in a bit.

Next, once you get it to idle, it's hard to do the final set up without a Uni-Syn to match the idle airflow to all 4 carbs. Getting that right, lets you fine tune the idle mixture better.

 

hmm, i do have a uni-syn for when the time comes. i am adjusting the twin screws. i hope i dont sound stupid but what and where is the idle speed screws on the holley 94s?

 

Just a Thought from an olguy, I run a tripower with the idle screws on the end carbs closed off, and the butterflies shut. then idle the motor off the center carb. This has always worked bitchin' for me, with progressive linkage of course. How about idling the center carbs, and shuttin' off the corner carbs. Again just a thought. Bowtie...

 

Idle speed screw should be only on one side of the carb, down low, by the throttle plate.

It is a slotted screw that opens or closes the lower throttle butterflies.

Maybe someone modded your set and tossed them?? Maybe the old 6 carb linkage was modded to have just one central aduster stop somehere else??

A single adjuster on the linkage would be OK for racing, but for street use and decent stable idle, each carb really needs it's own stop screw adjuster. Then when you have those, you unhook all the linkages to set the air flow on each carb using the Uni-Syn.

The Uni-Syn just measures how much air is flowing through a carb, You adjust each carb idle stop to get them all the same.... but only after you get the twin mixtures close on each carb.


Your video shows you holding the linkage in a certain point and it actually idled down to 800 or about, so really you need those ajusters to hold each carb open a tick to do what your hand is doing.in the vid

 

Adding to F&J's excellent post:

The idle speed screw (or throttle positioner screw) on the Holley 94 is located on the rocker linkage that connects the throttle and choke arms. The screw presses against a flat area of the throttle arm. When the choke arm is moved to the choke closed position, the rocker would rotate slightly, causing the screw to slightly rotate the throttle, thus acting as a "fast idle".

It appears that all of this has been removed in the picture.

Getting a decent idle for street use without the screws will be an exercise in futility!

If someone brought me such a setup, I would tell him it can't be done economically. Then if he insisted, and was willing to pay by the hour for an unlimited number of hours, I would approach the problem by machining custom brackets and idle positioner screws for each carburetor to replace those that were removed OR simply reinstall the rockers and screws without the chokes. Once one has idle positioner screws on each carb, the system may be tuned. The Uni-syn would certainly be essential; but the presence of idle positioner screws even more so.

Jon.

 

can you post a picture of the other side of the carbs?

 

I would do like bowtie40 suggests and run the two centers as primaries
and the corner carbs as secondaries

using carbkings suggestion of adding choke linkage to those two carbs

and F&J's suggestion to use your uni-syn to dial them all in

here's a snapshot of what the idle speed screw and choke linkage should look like
(sorry it's so blurry, must still be early in the morning)

 

hey guys i got it al straightened out before all these kick ass replys of course haha. im sure other guys will get good use out of this. everything works great now and thanks to everyone and thanks to dickster for taking the time to help me out. the hamb rules! i'll get a video of me driving it up after this weekend hopefully!