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Yet another tuning question

nutz4spd

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So here's my setup. I have a 413, that is pretty much stock I believe, with an electronic dizzy, MSD 6AL , Edelbrock intake and Holley 600 carb. It had a FiTech throttle body but the pump was going out so I'm switching it back to a carb. I bought the carb used and the pervious owner said he only ran it twice on his vehicle before removing it.

I have been adjusting this and that, reading, checking this and that, and reading some more. I have it to the point where it idles ok at about 700 rpm once warmed up. It does have a slight stumble upon take off and I can't get it to stop dieseling when I shut it off. The secondaries and primaries are fully closed too. I haven't had to adjust the primaries for idle purposes...yet. The floats have been adjust to where gas just barely trickles out when I rock the car while it's running. I have the timing set at about 8-9 degrees advanced at idle with the vacuum advance hooked to the port on the carb. This setup makes the motor ping pretty good under load. If I leave the vacuum advance off it doesn't ping but feels a little sluggish. Could just be me. What am I missing?? Should I set the timing at zero degrees at idle with the advance hooked up? What about the dieseling? I can't seem to get this thing to stop pinging and running on. Mind you it didn't do any of this with the throttle body.
 
Does the idle change when you connect the VA? If yes, then two possibilities:
- the VA is connected to a manifold vac source
- pri blades are open too far accessing the ported VA port. This is possible if the engine has a big[ger] cam.

Dieseling. Surprised it does it at 700 rpm. Old engine with a lot of carbon in the chambers?
Auto or Man? What happens if you try & reduce idle rpm, does it run rough?
 
Does the idle change when you connect the VA? If yes, then two possibilities:
- the VA is connected to a manifold vac source
- pri blades are open too far accessing the ported VA port. This is possible if the engine has a big[ger] cam.

Dieseling. Surprised it does it at 700 rpm. Old engine with a lot of carbon in the chambers?
Auto or Man? What happens if you try & reduce idle rpm, does it run rough?
No, the idle stays the same.

Possible I suppose. The one plug I pulled wasn't gummed up. It was a little orange around the insulator and the rest....well... now that I went back and looked at the plug, it does have a little carbon on the edge. It's a manual. At this point the idle screw is all the way out so it's idling on its own without having to adjust it. If I turn the mixture screws in (leaning it out) it will start idling lower.
 
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Are you sure the throttle cable isn't keeping it from completely closing the blades?
You should be able to get it to run at 550 if you like.
 
Are you sure the throttle cable isn't keeping it from completely closing the blades?
You should be able to get it to run at 550 if you like.
Yep. I pulled the cable off and the linkage was still fully closed. 550... that's not too low is it?
 
Yep. I pulled the cable off and the linkage was still fully closed. 550... that's not too low is it?
The idea was that the throttle was closing all the way and not held open by something else mechanical.
And yes you can idle down to 550 rpm with a stock engine.

If you can't get it to idle lower then you may have a vacuum leak
 
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The idea was that the throttle was closing all the way and not held open by something else mechanical.
And yes you can idle down to 550 rpm with a stock engine.

If you can't get it to idle lower then you may have a vacuum leak
Gotcha. I'll see if I can get the idle down then. I just thought that was too low and that it should be more around 750. I just put new plugs in as well. I'll find out at lunch time today how she does.
 
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