Something weird going on

[734406pk]

  That's GREAT NEWS! ENJOY YOUR CUDA! 

[joes74challenger]

Congrats! Glad to hear the good news!

Sent from my SM-G920V using Tapatalk

[73440]

All right!
And maybe all the others things you worked on during this will help it run better .
For wires touching, I thought that was a problem if wires that are in the firing order and were touching may misfire. Like 5 and 7 which are beside each other.

[cudabob496]

yes, I've heard about #5 and #7.
Was mainly referring to all the separation of MSD ignition wiring that
was being recommended by MSD.  I"ve put most wiring back to the way it was.
and running fine so far.

The car today did seem to be running sharper and quicker. In past 4 months have put
in new plugs, new mag pickup in distributor, new coil, removed variable timing unit,
and new ground wire for MSD box. But I'm not powering 6AL box directly off battery in
trunk, as MSD recommended. And still routing ignition wires through same hole in firewall.
I am keeping the MSD wiring going to coil and distributor separate from other wires.

[cudabob496]

gonna run some new plug wires soon.

So, AFR at idle is about 12.0.  Each 4 corner idle screw is
at 1.5 turns open.

How would I get AFR up to 13 to 14 at idle?

At full or part throttle, AFR is 12.5 to 14, where I like it.

[cudabob496]

Sooooo good to hear!     we all can learn from this, at least I did. Thanks for posting it all.

Bob I'm looking for an AFR, do you like the one your using?

Yes, its a great tool. Got from Summit about 5 yrs ago, all for under $200.  Brand is AEM.
and you don't have to weld in a bung to your exhaust. They have strap on ones now!
Very sensitive, even if you slightly change four corner idle adjust screws.  When I first
started up, the AFR was about 11 while cruising. My jets were 84/84.  Now they are
77/84, and AFR is around 12.5 to 14. They are a must have, IMO.

[73440]

http://not2fast.com/NACA/

I was trying to find NACA 49 which talks about low vacuum at idle having variable afr , when found this collection of articles.https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091078.pdf

What is your vacuum at idle?
http://racingfuelsystems.myfunforum.org/viewtopic.php?f=31&t=18

I dont know if this applies in your case.

Was looking for a simple article of how to change afr but these articles seem to be more involved .

[cudabob496]

lotta good tech info there.
idle vacuum is around 10 to 12 in gear.
if the 4 corner screws don't help, I'll just live with it.
If I had the billet metering blocks with the adjustable jets and bleeds, could
probably fine tune it a lot better.
thanks

[cudabob496]

This is a super book. And there is an updated version.

http://www.bing.com/images/search?view=detailV2&ccid=jblCsZ4A&id=6C4DCF4416B1EA611EA93365201A0D01426B6786&q=dave+vizzards+holley&simid=608033221469538806&selectedIndex=1&ajaxhist=0

[73440]

Yep, had two copies , dont have a holley , still using an original Carter, so gave them to two members here.

[cudabob496]

well, my 4 corner idle adjusts were at 1.5 open.
but my idle AFR was 12.0
So, I turned each adjust screw in .25, to 1.25
AFR at idle now 13.2, which is good enough for me.
Idle vacuum is also up near 13 now, so that is good too.
Idle rpm is 1200 to 1400, which is recommended for my cam.
But, cruising today, AFR is about 15 under part throttle, so
gonna raise primary jets from 77 to 79. I guess this is to be expected,
since carb has new metering blocks.

[cudabob496]

well, turns out I was at 79/86

so now its 81/86, and we'll see how the AFR does

[734406pk]

Your carburetor is responding well to adjustments, you should be able to dial it in easily with the AFR gauge...more horsepower from less fuel, it's all good!

[cudabob496]

Your carburetor is responding well to adjustments, you should be able to dial it in easily with the AFR gauge...more horsepower from less fuel, it's all good!

makes you wonder how we lasted with no AFR meters

[734406pk]

It was all by spark plug color, very rough indeed. After many hours of carb tuning, it's easy to see why EFI was needed when you realize that you are the ECM.