Lean under load

[67cuda360]

I'm running lean under load (going up a hill at low RPM), what do I need to change to richen it up a bit? I have installed a A/F gauge and here are the readings i'm getting:

- Idle is around 13 - 13.5
- Part Throttle (Highway driving) 13 - 13.5
- Full Throttle 10.5 - 11.5 (so too rich, should probably lean out the secondaries a bit)
- Part Throttle under load: 15.5 - 16 (going up a slight hill in top gear at low RPM)

Specs:
- A/F Sensor installed just behind the passenger side manifold flange
- 650 Edelbrock Thunder AVS
- '74 360 with electronic ignition, 18 initial and 36 total timing.

 

[360duster]

try the next stiffer step up spring for the metering rods. It seems that the vacuum is keeping the rods from moving into the power mode.

I´d try to lean out full throttle, too. No need for AFR 11 in a NA application.

Michael

 

[RustyRatRod]

You have a century ahead technology air/fuel measuring device on a century behind air/fuel mixer. You will never get a carburetor to be 14.7 at idle, 14.7 part throttle and 14.7 at WOT. Ain't gonna happen. I agree about the step up spring. I think you can get it closer than it is, but it will never be perfect, simply because it's a carburetor.

 

[67cuda360]

I realize it will never be all at the perfect metering, but thats a little lean for my taste i'll try the step up springs and i should probably go one size down on the secondary jets.

 

[OldmanRick]

This may give you a headache reading it :mrgreen: , but if you don't already have it, there may be some good info for you.......

[ame]http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf[/ame]