Holley experts

by Sinister Sat Jul 20, 2013 12:05 pm

I cannot get my 3310 adjusted correctly.
In order for the car to run,the float levels must be set high.
Running an electric pump running 7 psi.
My adjustment procedure is as follows.
Once the car is running,lower idle as low as it will go and adjust idle mixture screws for best vacuum.
Adjust float levels so fuel just spills from the sight plugs.
Once I lower the float levels car stalls.
Any thoughts?

by dynchel Sat Jul 20, 2013 12:31 pm

I would try to not lower the idle so low initially, adjust the mixture screws like you said, then reset idle speed.

by Bruisr Sat Jul 20, 2013 6:42 pm

Most holley books say to use idle screw to maintain idle, low enough to keep a steady idle, Then adjust air/fuel mixture for best vacuum, then use idle screw to raise or lower to the desired speed. Idle should be no lower than 700-800 rpms. Nice thing about holley mechanical secondaries, is you can open or close the secondary throttle blades to compensate for too much idle screw adjustment. Can you verify that your secondary throttle blades aren't opened at all or too far?

by Sinister Sat Jul 20, 2013 7:02 pm

Mixture screws are only on the front of carb..dual feed lines.
lowering the secondary float have affect on the front bowls?
I'm currently just working on the front bowls as the power circuit runs fine once car is running?

by ant7377 Sat Jul 20, 2013 11:26 pm

No affect on the idle from the secondary side. Some carbs are four corner idle but I guess not yours. Start with the timing before anything . What I do is turn the screws in as far as you can with out stalling the motor,then set the idle to your desired rpm (700-750 does it) the motor will run rough. Then using your vacuum gauge slowly about an 1/8 of a turn at each screw back them out watching your vac gauge go side to side. when it stops climbing you know you are set then back the idle screw down to where you want it since at that point the motor will be idling very fast. You are setting the idle screw first thats why its stalling.Idle is too low you are closing off the idle flow. On a plus side you know you dont have a vacuum leak.

by pila Sun Jul 21, 2013 8:57 am

Which engine ? I've had a 3310 on my 400 since the late 80s. I did some tuning on it originally, like tweaking jet sizes, put a trick kit in it etc, and it's worked great (except for gas mileage:D ). I rebuilt it a few years ago, because of age, but nothing else.
Sounds to me like something else is going on with your engine, which is affecting the way it runs.
What initial ignition timing do you have ? 10 degrees BTC should work OK....
Possible vacuum leaks ?
If the engine is a 350, that carb is a bit big for it. Lower vacuum signal from a 350 versus a bigger engine etc....

by Sinister Sun Jul 21, 2013 9:24 am

No timing tab or tape on the vortec motor.
I'm close on the timing as you know how small the window is.
Any major movement of the dizzy and the car wont start...its not perfect..but close enough to get the carb dialed in.
I ordered new needles seats to see if the problem will go away..if not I'll be ordering a new carb.
Even a vacuum secondary 750 shouldn't be too big for a 350..since vacuum controls the air through the carb.

by Sinister Sun Aug 04, 2013 9:55 pm

Got the new needles installed and now notice the gasket is wet between the intake and the carb spacer.
You guys run a gasket between the manifold, spacer, and carb?
I may just remove the spacer altogether.

by dynchel Sun Aug 04, 2013 10:02 pm

I don't run a spacer, but I do believe you are suppost to have a gasket on both sides of it.

by ant7377 Sun Aug 04, 2013 10:26 pm

Right ,gasket on both sides,massive vacuum leak with out it.

by pila Sun Aug 04, 2013 11:32 pm

Yes..two gaskets. Surfaces aren't usually mated good enough to run with no gasket......
Maybe that's part of your problem ??

Hope to hear that you get it figured out.....

Bill

by Sinister Tue Aug 06, 2013 1:49 am

I'm running a gasket on each surface.
No vacuum leaks but after sitting over night I can see seepage onto the intake manifold.
The gaskets are cheap thin paper gaskets.
Any better choices in gasket material?
I removed the carb to install the smaller spring loaded off road 97 seats...as they need to be installed with the carb inverted.
I will maybe try the carb without the spacer and see what happens.

by bracketchev1221 Tue Aug 06, 2013 12:25 pm

I use the Mr. Gasket carb gaskets. They are like a rubber/synthetic combo. My question is, why is it leaking on the intake? The carb should not be leaking anything anywhere. If you can get away without using a spacer go for it. On street cars, I use them usually just to clear the vacuum fittings on the back of the intake.

by ant7377 Tue Aug 06, 2013 9:27 pm

Strange. Put a straight edge on both surfaces,see what it looks like.

by bigredlaguna Wed Aug 07, 2013 2:18 am

I once had brand new fuel bowl gaskets that didn't seal properly, resulting in a fuel leak. I can't think of any other place that fuel could leak from on a holley. Your gaskets may leak just enough to wick into the base gasket by hanging on to the surface of the carb until it reaches the base gasket.

by dynchel Wed Aug 07, 2013 6:43 am

If I remember correctly, last time I rebuild mine was because the accelerator pump was leaking.

by ant7377 Wed Aug 07, 2013 7:47 am

Could be the thin gasket between the main body and the base plate. That is pretty thin and could tear easily. The accelerator pump is an easy fix,just pop off the front float bowl and change it.

by pila Wed Aug 07, 2013 10:40 am

If you suspect a vacuum leak, that's affecting the way it runs, you can use a propane torch ( un-lit of course !) .
With the torch turned on, pass the nozzle around the intake gasket area, and around the base of the carb. If there's a leak, the RPM should pick up a bit above normal idle speed when a leak pulls propane into the engine.

by Bruisr Fri Aug 09, 2013 8:35 pm

Can you get the engine to idle at all? Do you notice any fuel dropping from the center squirters? For some reason I feel the size 97 needle assembly is too big, especially for your 350. If that is the case, adjusting float levels will do nothing as the 97 needle is allowing too much fuel in. Just my thoughts!
I run a proform mech. secondary 750 without the chokehorn, on my 350 or 454 (which is what I bought it for), when I swapped to my 350 all I needed to do was lower 2 jet sizes in the primary side. If there is a float sticking or being overfilled, it will leak fuel from the center squirters. First check like Pila said and eliminate the possibility of any vacuum leaks, check the intake gaskets, and don't forget to check your vacuum advance. Those little diaghrams can hide a leak.

by bigredlaguna Sat Aug 10, 2013 2:09 pm

7 psi seems to be a bit high to me also. It's possible to overcome the needle seat with too much pressure.

A carburetor doesn't require more than 6 psi, and can run just fine with as little as 3 psi. The trick is to have enough flow to meet the demands of the carb.

by Sponsored content

Holley experts

Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts

Re: Holley experts