Idle issue on my 440...

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dkbug

dkbug

Well-Known Member
Joined
May 11, 2011
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Location
Norman, Oklahoma
Specs are as follows.
440
30 over
.538 MP cam
727
Not a stock converter, not sure on the stall though.
eddy 1407 carb


Started reading another thread and saw that he was having what seemed to be the exact same issue I am having. In park, this car idles like a dream. However in drive or reverse, this car will not idle at all.

I rebuilt the carb and am having the exact same problem as before. I started spraying for vacuum leaks, and I found that when I spray by the runners of my intake, it idles up. When I spray the base of the carb, it idles down.

Now, in drive I have the RPM set somewhere around 1500, in drive, obviously if you see the video I post with this, it tanks. When I am on the gas, the car has NO trouble going seeing as how my neck is kind of sore and I think I have a case of whiplash from punching it....:burnout:

Also, I attached a video showing the play in the shafts of the carb. What do you guys think?

I am not sure on my timing as I haven't had the chance to get a timing light yet, however I am pretty sure I am close to where it needs to be.


[ame]https://youtu.be/eqHbquM8Xm8[/ame]

[ame]https://youtu.be/FwAXUiEZr0k[/ame]

[ame]https://youtu.be/yEQseF2XwUA[/ame]
 
The carb throttle shaft bushings look like they are junk.

What is the initial timing on your engine? It should be in the 20* range is my guess.

It has the indications of a vacuum leak and dropping timing when placed in gear.

I'd find a known good carb and put it on your car and see if some of the issues, especially the high idle rpm, clear up.
 
dkbug said:
I rebuilt the carb and am having the exact same problem as before. I started spraying for vacuum leaks, and I found that when I spray by the runners of my intake, it idles up. When I spray the base of the carb, it idles down.
Click to expand...

Yup, vacuum leaks.
 
have done a LOT of carb work on AFBs i think Carter says that the shaft should have NO more than .004-.005" clearance. i would put bronze oil-lite bushings in them.. if you dont know how DONT try it. the main tricks are seating the throttle plates. which if not done right will make your trouble worse. and the screws are not easy to get out and then you have to be sure they dont come out later. the big Q you need to ask your self is do you have a return spring that is to stiff?
 
Ended up buying a new carb and man it made a huge difference. I still have quite a it in RPM drop but I am about 80% sure it's because of my converter not being high enough stall for my cam choice. I am now shopping around for a TC.
 
yes those throttle shafts are seriously worn.....no good for trying to make a good idle. I agree with the higher stall TC would help too.
 
dkbug said:
I am not sure on my timing as I haven't had the chance to get a timing light yet, however I am pretty sure I am close to where it needs to be.
Click to expand...

You guys kill me. The number one cause of big rpm drop is NOT usually torque converter related.

Get the timing squared away because that cheap to do.
 
Okay so, just thinking out loud here;

Timing, timing,.........................What's your timing? Did you defeat the Vcan?
Transfer-port sync up, have you set it?

Why don't modern 4bbl carbs have an adjustable idle-air bypass, front and center?

Why are there no 5 bbl carbs?
 
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