Any help appreciated with my feedback carb.

My truck recently started idling rough and idling rich. I'm getting a 72, 73, 42 (rich) code and I'm sure I'm performing the goose test correctly. I've ran this test in the past with no problems.

What I've done,

New TPS
New Idle Mixture Solenoid
Tested spark wires
Cleaned cap and rotor
Check for Vacuum leaks
Cleaned plugs
Tested MAP sensor
Tested TPS
Tested ISC (Idle speed Control)
Swapped in known good ECU
Testing leads going from TPS to ECU

Looking at the wiring diagram the black lead coming off the TPS is tied in with the switch on the Idle Speed Control.

What I found was the Idle Speed Control switch (on the end of the piston) has over 3 ohms of resistance. This seems high for a switch. I isolated it down to the ISC switch on the carb.

Does anyone know if this is normal? Seems like it should have no resistance unless there's a resistor in the switch.

​​Thanks.

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3 ohms is high but that might be good enough for the computer. How long has it been since the carb was rebuilt?

 

I'll check my records. I bought the truck from a neighbor and he gave me all the records and I know he rebuilt it a couple times. It looks pretty clean. I'm pretty sure it's electrical. The computer insists that I'm not "goosing it".