Hello Friends, Its been a while... Been Working on my Dads Truck, Installed a Carb Cheater and while its doing Good (19.417, 15.2, and 21.043 MPG Recently) looking at the Data Logs its Randomly going Rich to the Point even the Carb Cheater cannot trim it up, its especially bad at idle - 1200 rpm (with CC turned off it's trying to run at 10.5-11.2 AFR) and I feel there's something wrong but im unfamiliar with this Goofy Carb as im typically a Holley Guy but this is apparently my only option with this AOD

Any advice on these things would be Greatly Appreciated or If Someone is Well known for Building These That would be awesome

 

https://www.garysgaragemahal.com/holley-4180c.html

https://www.carburetor-parts.com/hol...uild-kit-k4098

 

At 1200 RPM that is not IDLE but cruise RPM on some overdrive cars / trucks.
Try and lower the IDLE RPM to factory spec and see if that helps as you should be back in the idle circuit and the idle mixture screws should then work to lean it out if need be.

The other would be to reach out to https://www.carburetor-parts.com/
as said
Dave ----

 

It generally idles 650-700 rpm in gear, with the Carb Cheater im able to watch the vacuum and AFR in real time and see how its responding, after 1200 rpm it leans back up appropriately, im thinking the issue is potentially related to these 2 ports, I don't have any information on what the purpose of these are as my older 2150s do not have them so I don't know if they need manifold, metered, or port vacuum like maybe I have them hooked up incorrectly

 

Again the 1200 for idle is not on the idle side of the carb so if you are trying to fix a rich / lean at idle you need to get it to idle.
That 1200 is just starting to tip into the high speed jet side of things .... just saying.

Do you have the vacuum sticker on the radiator support maybe that will help where the vacuum should be hooked to?
I have a 300 six and all the smog has been removed so not even close to knowing where the hoses get hooked.

I want to say I do remember someone saying what that was? Maybe DaveF? it was a year or 2 ago and dont know what to even search for
(bump)
Dave ----

 

The top arrow goes to a added gizmo on your carb that lessens the accelerator shot when the engine is warm. Leave it disconnected, it does no harm.

If the lower arrow port is sucking air at idle or when you rev it, it needs a cap on it.

 

This is an EMISSIONS CARB and cannot be modified/tuned as was the H4150/4160.

It is TAMPER RESISTANT but can be modified somewhat once you understand it.

FORD WSM HERE - https://www.garysgaragemahal.com/198...justments.html

 

Thank You! We will cap those off and give it a try to see if it changes the issues we're having, Much Appreciated

 

UPDATE Your assessment was correct, lower port had failed and was filling vacuum line with gas , we capped the lines to both ports and the duty cycle on the Carb Cheater dropped from 80-100% at idle down to 0-22% and after idling around for 30 minutes with CC off and on never dropped below 12.5 (off) AFR and generally stayed in the 13-14 range, with CC on it kept between 13.8-14.5 THANK YOU Franklin

 

Do you have a link to this Carb Cheater?
Dave ----