electric choke/ operating in reverse at start up

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gordo9

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gordy
Truck Year
85
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Sierra 2500
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350
1985 350/ quadra jet 4 bbl. emissions removed/ vacuum lines still installed.

Scenario : get in turn key, if its cold out choke light doesn't come on ( 1 pump choke plate does set). If it warm out or warm engine choke light comes on.

it"s one wire to choke, so it can't be reversed with anything??? wire appears to be connected to oil pressure switch? on side of distributor. position about 3 o'clock looking at distributor .

carb is rebuilt, high low advance all set. when in the shop operates as it should other then start, but suspecting that when driving choke is on too some degree. 5 mpg and a little sluggish under load. and thoughts and suggestions greatly appreciated.
 

Turbo4whl

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Wayne
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1974
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Jimmy
Engine Size
350
The choke light works backwards from what some other systems work. Turn the ignition on, power is fed to the oil pressure switch. The light is wired to that side of the switch too. Non running engine pressure switch is open, current to the light only. Start engine pressure switch closes, current to the choke heating coil. The light goes out because the bulb resistance is higher than the choke coil. Electric flow, path of least resistance.

The fact the choke does not set could be an adjustment or bad coil parts.

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Ricko1966

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Rick
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1975
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c20
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350
Low oil pressure, choke oil pressure switch is bad( and it's not typical oil pressure switch normally open closes with pressure) open circuit to choke oil pressure switch.
 

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