Carburetor engine difficult cold starting

[RigerZ]

I have a 1981 Datsun 120Y which very often has trouble starting in cold weather, especially after overnight rain. Even using the choke doesnt seem to work. I'm pretty sure the problem lies somewhere in the carburetor, but my dad suspects the ignition coil isnt making enough voltage for the spark plugs.

But then again I do notice my battery is significantly weaker in colder weather and the cranking isnt as strong. When I give it a jump start the engine would start almost all the time. I seem to understand that the weaker battery would cause the following (please correct me if mistaken):

- Slower cranking leading to weaker compression in the cylinders; air/fuel mixture doesnt burn properly

- Less voltage going to the ignition coil and finally to the spark plug; weaker spark doesnt ignite the air/fuel mixture

Anyone knows any other possible causes of this problem?

 

[vr2turbo]

Why not just change the battery and try. If okay, problem solved.....

 

[Supra_Fanatics]

I have a 1981 Datsun 120Y which very often has trouble starting in cold weather, especially after overnight rain. Even using the choke doesnt seem to work. I'm pretty sure the problem lies somewhere in the carburetor, but my dad suspects the ignition coil isnt making enough voltage for the spark plugs.

But then again I do notice my battery is significantly weaker in colder weather and the cranking isnt as strong. When I give it a jump start the engine would start almost all the time. I seem to understand that the weaker battery would cause the following (please correct me if mistaken):

- Slower cranking leading to weaker compression in the cylinders; air/fuel mixture doesnt burn properly

- Less voltage going to the ignition coil and finally to the spark plug; weaker spark doesnt ignite the air/fuel mixture

Anyone knows any other possible causes of this problem?

I was thinking the same whether my carb kancil is also because of this problem. Actually happens after replacing the spark plugs and the plug cables to borsch ones. :hmmmm:

 

[vr2turbo]

I was thinking the same whether my carb kancil is also because of this problem. Actually happens after replacing the spark plugs and the plug cables to borsch ones. :hmmmm:

Yours is still the old battery?

 

[DanzEterna]

I have a 1981 Datsun 120Y which very often has trouble starting in cold weather, especially after overnight rain. Even using the choke doesnt seem to work. I'm pretty sure the problem lies somewhere in the carburetor, but my dad suspects the ignition coil isnt making enough voltage for the spark plugs.

But then again I do notice my battery is significantly weaker in colder weather and the cranking isnt as strong. When I give it a jump start the engine would start almost all the time. I seem to understand that the weaker battery would cause the following (please correct me if mistaken):

- Slower cranking leading to weaker compression in the cylinders; air/fuel mixture doesnt burn properly

- Less voltage going to the ignition coil and finally to the spark plug; weaker spark doesnt ignite the air/fuel mixture

Anyone knows any other possible causes of this problem?

i tot all old cars has problem during cold start, had a Toyota LE before gotta pump the accelerator when turning the ignition

 

[Supra_Fanatics]

Yours is still the old battery?

New bro. Changed to NMF battery. Just recall after changing the plug cables and spark plugs and also did the air valve on the same day. Only got such problem after that. Before that it was okay.

So not sure if the spark plugs is the wrong one given. Plug Cables are borsch.

 

[vr2turbo]

New bro. Changed to NMF battery. Just recall after changing the plug cables and spark plugs and also did the air valve on the same day. Only got such problem after that. Before that it was okay.

So not sure if the spark plugs is the wrong one given. Plug Cables are borsch.

Then is new battery mah! Not battery issue dy......

 

[RigerZ]

i tot all old cars has problem during cold start, had a Toyota LE before gotta pump the accelerator when turning the ignition

Thats what the choke should be for, but on my car the choke doesnt help :(

 

[Supra_Fanatics]

Then is new battery mah! Not battery issue dy......

Could it be plug cables or spark plug problem? Cold start only problem. Always have to step on gas a bit to prevent it from dying off. Another way is crank until start. If die off, start again 2nd time then it will be okay. 2 way. But step on gas vibration not that bad.

 

[vr2turbo]

Thats what the choke should be for, but on my car the choke doesnt help :(

Have you ever had the carb serviced? Could be dirty and choke not working?

---------- Post added at 07:49 AM ---------- 6 hour anti-bump limit - Previous post was at 07:46 AM ----------

Could it be plug cables or spark plug problem? Cold start only problem. Always have to step on gas a bit to prevent it from dying off. Another way is crank until start. If die off, start again 2nd time then it will be okay. 2 way. But step on gas vibration not that bad.

Sound like fuel ratio is lean for cold start. Try the choke or like you say just step a bit on accelerator until stable. No two cars start the same way. Even my VR sometimes stable, sometimes chokes and cough, step of accelerator a while and then stable...hahahaha

 

[kazukimy]

Change battery, if it is done, check your carb, try to service it, den tune it...used to do tat to my tiara, running on carb...

 

[Supra_Fanatics]

Have you ever had the carb serviced? Could be dirty and choke not working?

---------- Post added at 07:49 AM ---------- 6 hour anti-bump limit - Previous post was at 07:46 AM ----------



Sound like fuel ratio is lean for cold start. Try the choke or like you say just step a bit on accelerator until stable. No two cars start the same way. Even my VR sometimes stable, sometimes chokes and cough, step of accelerator a while and then stable...hahahaha

Yup doing that every morning Step on gas a bit and let it run gradually awhile. Then only jalan. After that the rest of the day should be fine unless I leave it till night time then got slight cold start problem. But is bearable.

Change battery, if it is done, check your carb, try to service it, den tune it...used to do tat to my tiara, running on carb...

How to tune? U mean adjust the choke?

 

[vr2turbo]

Yup doing that every morning Step on gas a bit and let it run gradually awhile. Then only jalan. After that the rest of the day should be fine unless I leave it till night time then got slight cold start problem. But is bearable.



How to tune? U mean adjust the choke?

Fong should have tuned it already, right?

 

[Supra_Fanatics]

Fong should have tuned it already, right?

Yup, but still have cold start issues Cuz by the time i reach there no more cold start issues.

 

[kazukimy]

Nope, adjust choke just merely open up throttle, use screwdriver and adjust the fuel ratio to the carburetor.

How to Adjust a Carburetor: 10 Steps (with Pictures) - wikiHow