Hey Folks!
Well just now I got my Carburators Secondary Solenoid off the carburetor it was so tight all this time I couldn't get it off! Well its corroded and when I gave 12v No click! So here is the culprit that made the Engine bog down when the secondary opened ! Well I think it is ? Any ways the question is I will order or get one Solenoid soon but after getting the new one I need to know if I should connect it straight to the Ignition ? Like the Primary one (Idle solenoid) because mine doesn't have a ECU.. If I connect it the ignition it will always be open am I right then the petrol will keep flowing in even when the secondary is closed... Should I make a Circuit for it or connecting it directly to the ignition like the Primary will work ?
Cheers mates Good day.
Carburator Solenoid Question
- Petros
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Re: Carburator Solenoid Question
there should be two solenoids, one cuts off the fuel when you turn off the engine, the other when down shifting. The one that cuts off idle fuel when you turn off the engine can be wired directly to the ignition, so when the ignition is on the solenoid is on (giving it fuel) and when you turn it off it cuts the fuel supply to prevent dieseling or after run.
The other one that cuts off the fuel when there is a vacuum on the engine, such as down shifting or between shifts, so it reduces unburned fuel when you are using the engine to slow the car. so this solenoid needs to run through a vacuum switch that engages or disengaged the solenoid depending on the amount of vacuum in the manifold. this still can be done without the computer, but it might have some annoying habits. Check out the manual on the operation of the system to see if it is worth rigging as it was intended, you may not need a computer, just a few vacuum operated switches.
It will run without either solenoid as long as you are getting fuel to the carb through these circuits. The one that prevents dieseling might be a bit of trouble if it did not work but it will still run okay. I once had a car that did that and I got in the habit of dropping the clutch with the car in gear when I shut the engine off. The other one will not affect drivablity at all, but will increase unburned H/C emissions when you down shift.
The other one that cuts off the fuel when there is a vacuum on the engine, such as down shifting or between shifts, so it reduces unburned fuel when you are using the engine to slow the car. so this solenoid needs to run through a vacuum switch that engages or disengaged the solenoid depending on the amount of vacuum in the manifold. this still can be done without the computer, but it might have some annoying habits. Check out the manual on the operation of the system to see if it is worth rigging as it was intended, you may not need a computer, just a few vacuum operated switches.
It will run without either solenoid as long as you are getting fuel to the carb through these circuits. The one that prevents dieseling might be a bit of trouble if it did not work but it will still run okay. I once had a car that did that and I got in the habit of dropping the clutch with the car in gear when I shut the engine off. The other one will not affect drivablity at all, but will increase unburned H/C emissions when you down shift.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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- My tercel:: I owna Cortina with a Tercel Engine 3A
Re: Carburator Solenoid Question
Thanks for all that info mate! but Still didn't get the answer I wanted I'm set with the Primary Solenoid that keep the car idle.. Its the secondary I'm having a issue with I need to know If I have to just connect it to the Ignition or Use a circuitPetros wrote:there should be two solenoids, one cuts off the fuel when you turn off the engine, the other when down shifting. The one that cuts off idle fuel when you turn off the engine can be wired directly to the ignition, so when the ignition is on the solenoid is on (giving it fuel) and when you turn it off it cuts the fuel supply to prevent dieseling or after run.
The other one that cuts off the fuel when there is a vacuum on the engine, such as down shifting or between shifts, so it reduces unburned fuel when you are using the engine to slow the car. so this solenoid needs to run through a vacuum switch that engages or disengaged the solenoid depending on the amount of vacuum in the manifold. this still can be done without the computer, but it might have some annoying habits. Check out the manual on the operation of the system to see if it is worth rigging as it was intended, you may not need a computer, just a few vacuum operated switches.
It will run without either solenoid as long as you are getting fuel to the carb through these circuits. The one that prevents dieseling might be a bit of trouble if it did not work but it will still run okay. I once had a car that did that and I got in the habit of dropping the clutch with the car in gear when I shut the engine off. The other one will not affect drivablity at all, but will increase unburned H/C emissions when you down shift.

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- Member
- Posts: 41
- Joined: Sat Jan 12, 2013 7:54 am
- My tercel:: I owna Cortina with a Tercel Engine 3A
Re: Carburator Solenoid Question
I read it again and again and understood thanks mateDiNka wrote:Thanks for all that info mate! but Still didn't get the answer I wanted I'm set with the Primary Solenoid that keep the car idle.. Its the secondary I'm having a issue with I need to know If I have to just connect it to the Ignition or Use a circuitPetros wrote:there should be two solenoids, one cuts off the fuel when you turn off the engine, the other when down shifting. The one that cuts off idle fuel when you turn off the engine can be wired directly to the ignition, so when the ignition is on the solenoid is on (giving it fuel) and when you turn it off it cuts the fuel supply to prevent dieseling or after run.
The other one that cuts off the fuel when there is a vacuum on the engine, such as down shifting or between shifts, so it reduces unburned fuel when you are using the engine to slow the car. so this solenoid needs to run through a vacuum switch that engages or disengaged the solenoid depending on the amount of vacuum in the manifold. this still can be done without the computer, but it might have some annoying habits. Check out the manual on the operation of the system to see if it is worth rigging as it was intended, you may not need a computer, just a few vacuum operated switches.
It will run without either solenoid as long as you are getting fuel to the carb through these circuits. The one that prevents dieseling might be a bit of trouble if it did not work but it will still run okay. I once had a car that did that and I got in the habit of dropping the clutch with the car in gear when I shut the engine off. The other one will not affect drivablity at all, but will increase unburned H/C emissions when you down shift.

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- Member
- Posts: 41
- Joined: Sat Jan 12, 2013 7:54 am
- My tercel:: I owna Cortina with a Tercel Engine 3A
Re: Carburator Solenoid Question
One more question are both the solenoids the same ? I mean do they do the same job ? They look pretty much the same
- Petros
- Highest Ranking Member
- Posts: 11941
- Joined: Sun Jan 28, 2007 6:31 pm
- My tercel:: '84 Tercel4wd w/extensive mods
- Location: Arlington WA USA
Re: Carburator Solenoid Question
I think their operation is the same, but they cut fuel off to two different systems. One is idle fuel, the other cuts it off from the main fuel supply jets.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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- Member
- Posts: 41
- Joined: Sat Jan 12, 2013 7:54 am
- My tercel:: I owna Cortina with a Tercel Engine 3A
Re: Carburator Solenoid Question
Yea the Idle one is connected to the Ignition so it stays open the whole time until I switch off... The Other one is on the secondary barrel When the secondary opens up it is activated.. Correct me If I'm wrong