cutlass throttle stop switch
March 31st, 2013, 06:41 PM
#1
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Join Date: Mar 2013
Posts: 29
cutlass throttle stop switch
Working on rewiring my 74 cutlass with the 455. Book mentions a throttle stop switch. Mines missing, the wires are there but the sensor is gone. do I need it? The schematic shows that it's hooked in to and override relay. Is this necessary, If so how does it all hook together?
Thanks
Thanks
March 31st, 2013, 08:06 PM
#2
Oldsdruid
Join Date: Dec 2007
Location: Southside Vajenya
Posts: 10,302
You can do without it until you find one. It's to prevent dieseling when the engine shuts off.
When you turn the ignition switch to RUN, its plunger extends and increases idle speed so the engine will run smoothly. When you turn the switch OFF, the plunger retracts and closes off the throttle plates so the engine will die. If you had it you would set curb idle speed by turning the plunger in or out to achieve desired idle speed.
If you don't have it, just use the idle speed screw on the side of the carb to set your curb idle at about 550-600 RPM in DRIVE. If the engine diesels when you shut it off in PARK, try shutting it off in gear.
That override relay should have been disabled long ago. It was the subject of a recall campaign. Way back in the dark ages of the guvmink nanny state, somebody decided cars needed an ignition interlock to prevent starting them with any front passenger position seatbelt unbuckled. This went into effect for 1974 model year.
As with most grand plans, nobody took the unintended consequences into account. The system was very prone to failure which is why the cars had that override relay- it was up on the firewall and had a button "Push to start". Some cars had to be overridden every time they were started- my parents' 74 Impala was one of them and it drove my Mama up the wall. I think that was one of the big reasons she hated that car.
A screwy weight sensor switch in the seat cushion would prevent the car starting, or even a bag of groceries or a purse would make the thing think there was someone in a seat that wasn't buckled in and it wouldn't allow the car to start.
The carmakers and the US Congress (who had foolishly enacted the law requiring it) got an earful from the general public to the point the law was quietly repealed and the carmakers sent out recall notices to bring the 1974 cars in to have it disabled.
When you turn the ignition switch to RUN, its plunger extends and increases idle speed so the engine will run smoothly. When you turn the switch OFF, the plunger retracts and closes off the throttle plates so the engine will die. If you had it you would set curb idle speed by turning the plunger in or out to achieve desired idle speed.
If you don't have it, just use the idle speed screw on the side of the carb to set your curb idle at about 550-600 RPM in DRIVE. If the engine diesels when you shut it off in PARK, try shutting it off in gear.
That override relay should have been disabled long ago. It was the subject of a recall campaign. Way back in the dark ages of the guvmink nanny state, somebody decided cars needed an ignition interlock to prevent starting them with any front passenger position seatbelt unbuckled. This went into effect for 1974 model year.
As with most grand plans, nobody took the unintended consequences into account. The system was very prone to failure which is why the cars had that override relay- it was up on the firewall and had a button "Push to start". Some cars had to be overridden every time they were started- my parents' 74 Impala was one of them and it drove my Mama up the wall. I think that was one of the big reasons she hated that car.
A screwy weight sensor switch in the seat cushion would prevent the car starting, or even a bag of groceries or a purse would make the thing think there was someone in a seat that wasn't buckled in and it wouldn't allow the car to start.
The carmakers and the US Congress (who had foolishly enacted the law requiring it) got an earful from the general public to the point the law was quietly repealed and the carmakers sent out recall notices to bring the 1974 cars in to have it disabled.
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