What if choke doesn't kick in when starting

Niels Schoon

Niels Schoon

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Hi,
Awaiting the carb problem (see other thread), I might have another problem. The choke doesn't kick in when cold start (I always put ignition on and press gas pedal once before starting). What could be wrong ? Is it electric related ?
 
Are you pressing it all the way to the floor? If the cold start linkage isnt engaging then it needs to be adjusted. The chokes should close up on their own as the engine cools, if not the choke actuators (small round canister) have to be loosened and turned in the direction of closing more but not so much that the chokes dont open fully when warm. Message me if you want the Zenith manual for the above procedures.
 
as described before is not electric related, only mechanical, it is a combination of serrated levers and springs
i have been fiddling with dozens of this carbs, and it is one of the faulty elements in most of them, in several cases due to not understanding the system it has been damaged or deleted in previous repairs
together with manuals, if you follow my serie of videos you will be able to see and know what to do

a good kickstart needs only a slight touch of the pedal to engage, if you go to the floor you inject the fuel of the pumps too, a good meassure if your car has been sitting for long time
 
Okay thanks... so let me try to describe the behaviour (since a few days).
Normally the car fires up the first time (with cold start) on high rpm (as I have initiated the choke and pedal to the floor). Now it has difficulties and doesn't fire up the first time. Extra gas kills immediate and I need to crank a while. As I tried to figure out what is wrong, I noticed that trying to give gas does kill the engine direct. I have to let the engine fire up (after a while) but that goes with stuttering. After 5 -10 seconds it start to run stationair and more smooth.
 
i am not aware of the history of your car, you are a recent member with few messages, i do not know if you have this car since new or you are a recent owner,
also to say i do not know your experience and skills on automotive issues and in this particular model

in my experience carbs are one of the important parts of these cars, zeniths have a bad reputation because mechanics do not take the time and efforts to understand them and thus to maintain them well

if they have been well kept and maintained or not makes a big difference, but if you do not know the history, youd better overhaul them at once, even brand new fully restored cars hide some secrets,... @Philippe db can tell you his story ;-)

what other owners express is certainly subjective, someone can tell you that his car runs well because he has no other reference to compare, please bear this in mind when others are giving their opinions

generally speaking you might have a problem in the choke mechanism, but is a complex thing, the only thing i can figure out are an easy check are primary butterflies

it seems extrange that you have missed a good behaviour that has been there for a while, but lets see

if you remove the air filter cover with cold engine, are the primary butterflies closed ? or open ?, if now you press the throttle linkage with your hand, what do the butterflies do ?

BTW adding gas always floods the engine so it wont start until it evaporates and recovers the right air/fuel ratio

BTW, Try not to start the procedure with "pedal to the floor", use a simple tiny push of the pedal

i will be happy to talk to you on the phone if you want, just let me know
 
a couple of easy checks also,
see if the primary butterflies are well engaged to their pushing rods
see if all electric connections are correctly engaged
and one more thing, show pics of your carbs, there are several different models out there
rgds
 
Good advice from deQ. I meant to the floor for cold start in the morning to both engage the cold start linkage and to prime with fuel as your pump is mechanical. Post pics of your carbs when cold and warm.
 
deQuincey said:
i am not aware of the history of your car, you are a recent member with few messages, i do not know if you have this car since new or you are a recent owner,
also to say i do not know your experience and skills on automotive issues and in this particular model

in my experience carbs are one of the important parts of these cars, zeniths have a bad reputation because mechanics do not take the time and efforts to understand them and thus to maintain them well

if they have been well kept and maintained or not makes a big difference, but if you do not know the history, youd better overhaul them at once, even brand new fully restored cars hide some secrets,... @Philippe db can tell you his story ;-)

what other owners express is certainly subjective, someone can tell you that his car runs well because he has no other reference to compare, please bear this in mind when others are giving their opinions

generally speaking you might have a problem in the choke mechanism, but is a complex thing, the only thing i can figure out are an easy check are primary butterflies

it seems extrange that you have missed a good behaviour that has been there for a while, but lets see

if you remove the air filter cover with cold engine, are the primary butterflies closed ? or open ?, if now you press the throttle linkage with your hand, what do the butterflies do ?

BTW adding gas always floods the engine so it wont start until it evaporates and recovers the right air/fuel ratio

BTW, Try not to start the procedure with "pedal to the floor", use a simple tiny push of the pedal

i will be happy to talk to you on the phone if you want, just let me know
Click to expand...
Hi there! Hope you are doing well,
Reading this 8 years old thread. Very interesting. And, I have a question: My coupe is a '75 injection with automatic choke, I believe, driven by a temperature probe. My car sleeps in my heated basement every night. So when I start it in the morning, it almost doesn't turn on the choke. Or just a little bit. As soon as I pull it out the engine revs up from about 1200 to 1600 rmp, or so. It usually takes me about 3 to 5 minutes to close the garage door, put on my jacket, shoes, or whatever is needed. Sometimes even a couple of minutes more to take the garbage out or whatever. So I was wondering: is that automatic choke absolutely necessary? because if the car engine starts fine, maybe it is useless to have the engine reving that high, while it could just sit there running at a lower rpm.
Another question: does it really help to press a little, or to the floor, the gas pedal before ignition? during ignition? Makes me realize that perhaps, when voltage is on, the fuel pump can pressurize a little amount of gas that would help the engine to start ? Because indeed, sometimes my engine starts, not at the first try, but at the second... Because I remember my old carb car that would start without pressing the gas pedal at all...
Thank you for your advice.
 
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