Another idle question from a blower newbe

Ok here is my problem, when I get the idle set where I like it my throttle gets really sticky down around idle, as far as I can tell the vacuum from the blower is pulling the plates tight. Ok I fatten it up some and it gets better, but when I do that the motor gets lazy and drops the front two cylinders. I really dont want to have it idleing like that.

Am I doing something wrong here??
572", std 8-71 @ 28% over, crower 8 port injector, has anyone else had this problem with this injector??
New 110 fuel pump.
timing is at 30*
.124 main

Idle pressure hangs right around 16-20psi, depending on where Ive got it set.

 

Possible vacuum leak around the hat area?

What is the gap at the blades?

Also, what did you set the leakdown at idle?

 

Blades

Check your blades with the motor off and the throttle cable disconnected. if they stick then, the blades may not be centered. the shaft may be off center, or have a small tweak in it. Do they close smoothly? Just a thought to check. Good luck Don

 

The throttle is smooth as silk when not running.
The gap is .006 and thats 8 2.812" bores.
I've had the hat off and I cant see any signs of an air leak.
I dont know the leakdown, I know, I need to get a tester.

 

Throttle Blades

Are the blades frosting up and sticking to the injector opening.
I have this problem once and a while. They frost and it takes a little bit to crack them open, when the engine is off the frost melts.

Just a thought
Corey

 

Mopar,

Do you have throttle stops on both ends of each shaft, if not, blower vacuum could be twisting the shaft on the end without the stops enough to tweak a slight bind. Also, make sure your barrel-valve hex-link center to centers are the same (or a least close) as the c to c on your bv and throttle shaft. Also check that the angle on your bv hex link rod arms are in the 45 degree range at closed and at full open. Sometimes if the rod arm gets adjusted at a much higher angle, it might still open smoothly, until you fire the engine, then the vacuum is too much to overcome with the decreased mechanical advantage. Just guessing but worth looking at. Are you guys going to Cordova this weekend?

 

How are you setting your idle and at what rpm, and, are all the blades at .006 and where are you checking them?

Another thought is, have you verified the barrel valve is correctly assembled? Reason I ask is that, when I bought mine, I didn't check it and had some real bad idle issues that turned out to be improperly assembled barrel valve.

 

Yes, we are going to cordova this weekend, untested as usual.

We're not having a problem opening the blades, its not wanting to all the way back to an idle, I may have solved it with a stiffer return spring, but its still bothering me.

The barrel valve is good and free turning, the .006 is at 90* from the shafts.
Idle rpm is at 1400-1500 now, I've had it down to 1100, and as high as 2000.