air bleed, rich, lean or perfect

after some great tips from mr6pk my 1970 440-6 is running great but I always have to tinker so yesterday I went out and pulled the aircleaner b ecause I read that a good test for air fuel mixture is to cover the airbleeds one at a time. When I do that the car stumbles really bad yet I am out 1-1/4 turns on the outboards and when idling it tends to get a little blue in the garage and at 1-1/2 turns out the car idles rough and my vacuum goes from 20 inches down to 18 inches. Did I read a missprint on this test or what?

happy you talked to Bob K. something to try but don't forget where you started from incase you end up being happier where it was.

i would open up the center carb 2 1/2 turns on both idle screws. then turn in the idle screws one at a time checking as you go while covering the air bleed and checking for a rpm change. if the rpm drops, richen the mixture, if rpm increases, lean the mixture. do thse one at a time and when you are done do it again. after you are happy that there is no change in rpm, the using a vacuum gauge adjust the idle on the center carb. then check it again.

all this is assuming that the timing is setup where it needs to be.

I called Holley and talked to one of there tech's and he said he never heard of anything so stupid as covering the airbleed holes one at a time. He said no matter where the idle screws are it will stumble. I think I am developing a brain tumor from all this info and misinfo. One guy says outboards out no more than 1/4 turn and I can not get the car to run at all. Then the next guy says 1-1/2 turns out and the car runs great. So let me ask just to make sure I understand, there should be no change in rpm's when I cover the airbleeds?

this is how my car is setup and i think it is running pretty well. all i can say is try it and if it does not work out, change it back to the way you have it now. you did say you think it is running better since you took the advice of mr sixpack. personally i would rather take the advice of mr sixpack over a holley "tech" any day.

if you don't mind me asking, what advice did you get from mr sixpack that helped you out?

Bob said set all screws center and outboards at 1-1/2 turns out, plug vacuum advance, start car, warm up and set timing at 12 BTDC. With vacuum gauge connected to intake manifold start with center car and adjust for maximum vacuum, then adjust outboards for maximum vacuum. By the way I purchased through Promax a throttle body for the rear carb where the screws come out side ways so the can be reached on the car. As of now I am pulling 20 inches of vacuum at 850 rpm's with the center screws out 1-1/2 and the outboards screws out 1-1/4. The car idles great, cruises great but as I said really bogs down when I cover a airbleed hole. Am waiting to hear fromBob on this to see what he thinks but if I have time may try your suggestion to see what happens. And ya I have lost all faith in the Holley techs. How weird that they don't know what to do.

just wanted to add that after talking to another mopar guy locally this morning that both outboards have two air bleed holes on each side and they both need to be covered at the same time and I was covering only the outside one. I am hoping this will clear up my concern. Learn something new every day, wow.

the air bleed closer to the center is for the main fuel circuit. if the throttle plates are closed there should be no effect when they are covered. this is why they say when checking the idle air bleeds, that they recommend having the outboards disconnected so that there is no question that the carb is only running in the idle circuit. so if the carb is closed you would only need to cover the idle air bleed.

thank you for clearing that up for me

macmic87, took your latest advice and reset the center carb 2-1/2 turns out, unhooked the vacuum and linkage to the outboards and started adjusting the outboards. I am now at just under 3/4 of a turn out with NO rpm change when I cover the outside hole and still pulling 20 inches of vacuum and the car idles great. Will test drive it tomorrow and get back to you. Between you and Bob you have really helped me out. If you ever need any carpenter advice just ask, been pounding nails for fortythree years.

now that you are satisfied with the outboards, you should still put a vacuum gauge on it and adjust the center carb screws one at a time and three times ina row to make sure you have the highest vacuum. with the screws out so far before on the outboards, alot of times that takes away any adjustability from the center carb. now you should be able to adjust the center and have it make sense.

thanks for the tip

macmic87, I test drove the car today and feel it is alittle lean, I got backfire on deacceleration and could feel a slight bog on cruise. I did as you suggested and double checked the center car with a vacuum gauge and between the vacuum gauge and the tach on the timing light I am maximum on vacuum, just a hair over 20 inches. Now for my question, would you adjust the outboards or the center to richen the fuel. Right now the outboards are at 3/4 and the center is at 2-1/4

i would double check all the float bowl levels. center just to the bottom of the hole and the outboards flowing out. if the plug was still there it should be half way up the hole. this is important!! if that is all set then i would take and give an extra 1/8 turn to all the outboard idle screws. take it for a ride and see what you get. now it is a matter of doing one thing at a time and see what the results are. seems like you are really close.

i don't remember, what is your timing at? initial and total mechanical and what rpm is it all in.

timing is 12BTDC and 41BTDC at 2500 rpm's. float level was checked before I posted last message. I am running with vacuum advance plugged per Bob's suggestion. Will drive on Saturday and let you know

Boy, you vacuum outboard guys have it tough.

mr6pk and macmic87, after driving the car last weekend it still was not correct and that is when a freind take a look at the spark starting with the easiest, the dist cap. To my supprise there was green inside the cap. I put a new cap on yesterday and the car runs great. I have also ordered a set of Taylor wires.

happy to hear it. now go out there and drive it like it supposed to be.