Monday, May 17, 2010

DIY: Carburetor Cleaning for 4G13p/15p

Before I start, I would like to tell what problem that I am facing now. My daily drive is a 18 years old Proton Saga equipped with a 4G15p. A lot of people will wonder why I am not driving Satria, Celica or Kancil instead of an old junk. For Satria and Celica, both modification done on them and the fuel consumption are not suitable for daily use while the Kancil is use by my dad so this is the reason why I am not using them.

Back to the problem, the aging 4G15p already clocking at 200K KM mileage and haven't done any major overhaul. Recently the engine will shaking after turn off the engine and the symptom looks like it running rich and there is fuel in the combustion area. The next problem is the fuel consumption is pretty high where about RM0.25 per KM and this consider bad for a 4G15p manual engine.

The first thing I plan to do is to clean the carburetor. Therefore I went to BROTHERS- a well known accessories shop but with a not very good reputation to get a carb cleaner and Unifide Clear-Out Carb & Choke Cleaner is my choice and it cost me RM22.90.

First thing to do is open up the air filter cover, remove the the air filter. You can clearly see the carburetor opening valve which it suck in air from the filter. I did not remove the entire air filter cover so can really see the whole carburetor.

Next, spray the carb cleaner to the carburetor without starting up the engine. You can obviously see that the carburetor is being cleared.

After that start the engine, press the throttle pedal and spray the carb cleaner into it. Beware that if you spray too much into the carburetor, the engine will die off. It is normal and just start the engine and repeat the above steps.

After doing that, the engine is easier to start. I already pump in a full tank of fuel. Let's see what happen after a week whether this will improve the fuel consumption of the aging 4G15p or not.


Hi, i came across your blog & i find this topic is interesting. ben, can i get some advice from you? my car is old proton saga(4G15P). black smoke come out from my car exhaust pipe& my fuel consumption is super duper high. So, i suspect my carburetor need to change but i know it will cost me a big of money which now im out of budget. thus, i interested to know the outcome after you apply the carb cleaner. is it work? or is there any other way beside using carb cleaner which i can save my carburetor rather than change the whole things?

Hi, it's works for my saga. Average help me to save up few cents for my fuel consumption and the engine run smoother compare to previously.

However for your case, black smoke from exhaust is your car running too rich. Which means that your fuel is not totally finish burned. There is a possible cause of this kind of problem is a stuck choke plate. Try to examine the choke, if the choke plate is nearly close or close then you car is suffering from stuck choke problem. Then apply the choke spray to it.

Besides that, try to examine your vacuum hose. Black smoke may cause by leak vacuum hose.

Alternative, you can service your carb. Bring to a mech and he will clean your carb and retune it. This will help as well and does not cost much.

hi ben, how to check the choke plate & vacuum hose? do you have any illustration for that? since it work for you, i will buy the carb cleaner you used for your car & then see the outcome. if it is still the same, then i send to the mechanic for service. thanks for your advices!it is very helpful & the illustration above is very clear& easy to follow:)

Hi, sorry that I do not have a picture of the choke plate. Anyway you can see it easily after you remove the carb from your engine. For checking the vacuum leak, you can use the carb cleaner or starting fluid and spray around the vacuum hose. Any noticeable change in idle speed and there is your leak.

I have found a carb cleaner but uncertain since my 4G15 is Gas while the carb cleaner says diesel? Is it the same cleaner you are referring to.

As long as it is a carb cleaner that it is suitable for your engine.

Is the carb cleaner effective in reducing your fuel consumption?

Yup, it reduce about 2 cent for my car.

My car seems to have water coming from its exhaust what can be the cause of this?


Water is a by-product of the combustion of gasoline. Gasoline does contain hydrogen, and when gasoline is burned, some of that hydrogen combines with the oxygen being used to burn it and then produce water.

Most of the time, the exhaust is hot enough that the water remains in the form of invisible water vapor. When the engine is cold, the exhaust pipe is cold, or the outside air is cold, this water may condense and become visible as "steam" or as liquid water dripping from the tailpipe.

Hi Ben,

Your saving is 2 cents after applying carb cleaner. Is this per liter?


My calculation is based on per km. As I posted in the post, my previous fuel consumption is about 0.25 cent per km and now is around 0.22-0.23 cent per km. So for full tank of fuel, I am able to save up about RM7-8.

Hi Ben,

I am not sure if this still related with this blog. My car (1989 Mitsubishi lancer/4G15) seems to shake too much when in Idle or when I turn on air conditioner? What can be the reason? Should I increase the engine revolution?

Hi, may I know what is what your engine rev during idling and air cond ON? If both are around 800-1000 rpm then your engine rev consider normal and try to check on your engine mounting.

The rev when idling is 1000 and it gets down to about 500 and the engine sometimes shuts off when the air conditioner is on also the whole car's body shake as well but shaking stops when I turn of the Aircon.


I am not sure your engine is running on carburetor or EFi. If yours are EFI, try to check the Fast Idle Control Device (FICD). If yours are carb, then try to adjust the aircond ON/OFF idle screw. If either still not able to solve your problem, most probably your aircond compressor is dying/jam.

hi ben, i like your post. my car (proton iswara 1.3manual 2003) having problem when i started it, it will shake badly and last for 1-2 minutes. no problem to started the engine, only the shaking, even when i press the throttle paddle the engine will shake heavily...

Hi Sandakanese,

You may check on the several things as below:

1. Engine/Chassis Mount
Any rubber or pad that has worn away will cause metal to metal contact between the engine and frame, causing a serious vibration.

2. Choke
A choke that does not close for cold-start conditions will not allow enough extra fuel into the intake manifold for combustion. A choke mechanism that does not disengage properly (open) will flood the engine and cause a noticeable vibration.

3. Fan Blades
Cooling-fan blades can wobble on worn-out hubs or fan clutches, causing a very noticeable vibration.

4. Pulleys
Check the harmonic pulleys for any perceptible wobble or noise.

hi, there i am having lancer and the engine is 4g13 is there any help i can get as i need the diagram of vaccum pipes proper assembling

Hi ben,
How can I check my Engine model.. I'm Using Iswara 1.3


Iswara 1.3 is using 4G13p. You can see engine model at the sticker on the firewall of your wall. Anyway this is only applicable if you have not change your car engine. Second method is to look at the engine number on the engine block.

Hi Ben,

Nice seeing such an informational blog...thumbs up for u bro...


Hi Ben,

car, iswara 1.3A/B manual. difficult to start in morning; very shaky but better after car moved and rpm goes to 800rpm.

auto choke problem? if it is, how to DIY? tq


Hi lantohsay,

It might be auto choke or thermostat problem.

Currently I do not have any post for this. Let me write up one later.


Hi Ben,

My Iswara 1.3 Air cond stops to function. The fan and compressor is not working when I start the car but if I do a bypass, both were working. Is it possible that my air cond hose is leaking?

Thanks a lot.

Ah Meng

Hi Ah Meng,

Have you check the relay that activate the compressor? I doubt that the air cond hose is leaking because if this happen only your gas will leak and won't cause the fan and compressor not working.


Hi ben,

Mine is Kancil 850ex. white smoke came out when i start the engine early in the morning. n after a few minutes it will get what is the problem?

Hi Madshark,

This is the effect of evaporation. It is normal.


Hi ben, interesting post, and I have a question, my 4g15 carb can't start, the UFO ( fuel pump) is working perfectly but it seems like the fuel is stuck in the carb, not flowing to the combustion area! When I close the mouth of the carb, and a friend try to start it, the carb is dry,no sign of fuel at all



i was wondering that my 85' saga original engine is a 4g15 means a 1.5 engine, right? my parents swap the engine long ago so the current engine is said to be a 1.6, some say its a mivec engine.

what i know is the engine's description is mitsubishi 12 valve cyclone. other descriptions are in Japanese.

since there are no paperwork (i assumed it's lost) how can i identify the engine?


I'm afraid that your engine is not a MIVEC engine. For a 4G92 MIVEC, it is a DOHC which means it has a 16 valves in it. By the way, you may search MIVEC in my blog for better understanding.


Hi Ben

I'm driving old Saga hatchback 1991, auto.
The problem is, i want to DIY tuning my carb.
Just want a clear up, that the bottom screw adjust is for aircond off idle.
The top one is for aircond on idle, and the middle one at bottom is for autochoke idle.

What is the best position for autochoke screw, near or far from the plate?


It is no best position. It depends on your car running during autochoke is on.


Hi Ben,

I have a 4g13 with a carb. In the morning the car starts but dies within 30 seconds if I don't accelerate. After few mins it runs ok. How can I tune the auto choke of this Pics will be great if you can provide. Thank you and Best Regards.

Ben. I would like to ask about 8v carbs on 4g15p. How do u tune it up. N how do u tune the 2nd butterfly to open certain rpm?

Hi Ben,

Mine is a Proton saga 94 model, I would like to boost the performance when driving uphill because it lessen the power at uphill condition and you can feel it dramatically.


Hi Ben,

Mine is Proton saga 94 model, my car has low power when driving uphill and you will notice it dramatically. How can I boost it performance?


Hi Mike,

First of all, please make sure that your engine is still in good condition. If so, you may slightly upgrade your car by changing to a bigger carburetor. If your engine is 4G13 and by changing to 4G15 carb, you will notice some difference. A lot of people saying 4G13/15 carb are both the same but try to compare side by side and you will notice that there is slightly bigger for 4G15.


Hi Ben I read all your explanations and modification's ideas on the ​​4G13/4G15 engines. View you seem to be an expert I want your opinion, I have in head to boost my Proton Arena / Jumbuck to 250hp or more and also to put a 4Wheels Drive. Thank you in advance for answer me, your opinion will be of great help to me .


Hi Jefferson,

You may opt for a 4G93T 1.8 Turbo engine. It comes with a 4WD gearbox.
Since Arena and Wira length and wheel base are almost similar, you can directly install the shaft to your car as well. However a 1.8T will not able to boost you to 250hp by itself. You need to have some modifications to it. For better option, you can opt for 4G63T 2.0 Turbo from an Evo.



Where is the autochoke idle screw located?



It located at the side of the carb.


Hi Ben,

Thanks in advance coz your blog too HELPFUL for iswarian anyway and me too..

And i got a situation here..I'm using iswara 1.5 auto 4g15 and the fuel consumption getting worst and worst..then my car vibrates a lot due to rpm gets low almost 300-500..after few days i saw black smoke coming out from exhaust and i already did top overhaul few months is it because of carburature or any other faulty parts..??


Black smoke indicates that your A/F ratio is not right. It is running rich. Try to check that.


Hi Ben, i m using 4g15 engine. the engine always tend to die off randomly. it happened few months back and now it begins to happen more frequently. i ve changed the fuel filter but the problem seems remain unresolved. and there's one more thing, the amount of white smoke coming out from exhaust is too high. i wonder isit normal cause sometimes i do travel quite a lot with this saga. Thanks in advance and hope to hear from you soon.


Can you try to clean your carburetor? Besides that, worn valve seal tend to show symptom of white smoke from exhaust.



I did something similar to u.. except i did it before seeing ur post.. I spray the carb cleaner to the throat and the 4 holes, as well as to the smaller hole u can see at the southeast direction connecting to the engine prior to starting and when it starts, it gives our popping sounds which i think is the backfire. Can you please advice on what can be done? It got worst than it was. Previously only stuck at 1.5krpm but now at everywhere below 3 and sometimes above 3.

Millions of Thank You in advance.

Hi Ben,
Please specify where to spray the carb cleanser into after the engine has started? to the middle throat or the 4 holes? Thanks.


Regarding the 3k rpm can you check on your choke plate whether it is stuck or not?


Spray to the middle throat.


Hi ben i have a proton wira auto 1.5 4g15 carburater..the problem im facin is sometimes my rpm will drop to the bottom & the engine will stop..sometimes my rpm is not stable..i have retune the the mechanic told me maybe the carb choke has a problem..the worse thing is in my state they is no mechanic willing to do a full service carb nowadays & even proton services centre too..pls advise..

Hi Fraincischong Chong,
Can you check your idle knob of your carb?

Hi Ben. Just want to ask if its ok to put on fuel pressure regulator and a rev limiter on a 4g13 carb engine lancer 1995. If possible, is it ok with you if I ask for a diagram so I could install it myself. Thanks Ben

Hi Ben, i am Jawwad
great information you have shared here. thanks

I have Iswara LMST 1.3 4g13.
1st issue when my idle is never same when AC is turned ON. Idle drops and car stalls
when car is hot my idle is 1050rpm when AC is not it drops to 700/600rpm

2nd when AC is on after 15/20 mins of drive the car stalls and doesnt throttle properly like my gas tank is getting empty but thats not the case.

hi ben,
i have a lancer 97 with a 4g13 carb...idle and rev the engine runs fine.. but when load comes it drops ,,and sometimes engine you have any idea about the problem?
thanks in advance