Tune 4G15 Carburetor

[Iroshw]

Hi guys,

I have Mitsubishi C62A (known as ASP Model 1991). It has 4G15 engine and very powerful. But I'm not happy with the fuel efficiency of this car. And there is a black smoke as well. I just surf the new and found this car does 14km/1ltr (average). But my one is doing nearly 8km/1ltr (without AC).

I was searching a solution through net since I'm really really tired with garages. I took my vehicle to a lot of place to solve this issue. But so far no good result.

I found some instructions from a forum. This is about tuning the engine (4G15). Please check this and let me know your feedback since I'm going to try this on Saturday .

1) Warm up engine first(run 5-10 mins)
2)Shut off engine
3) Back out on the idle speed screw until it justt doesn't touch the throttle linkage. Then screw it in back about 11 turns (what this does mean actually?)
4) Screw in the A/F mixture screw until it stops(do not force tighten)
5) Screw out the A/F mixture screw 2 full turns
6) Start the damn car. It will run like its choking. As long as it's running it's ok.
7) Now turn in the A/F screw until engine dies. If this happens, turn out the A.F screw half turn at a time to bring it back. (try to start the car of coz) (what this does mean?)
8)Continue to turn out the A/F screw at half turns every 3 seconds. Engine will pick up speed. Continue to screw out until the point engine runs worse. When that happens screw back in half turn every 3 secs to the point engine runs smoothest.(do this by ear or watch engine vibration) (what this does mean?)
9) Now set the idle speed. Go on the air conditioner. Watch the tachometer. Turn in the idle speed screw until rpm is around 900 to 1000 rpm.
10) Now it's ready to rumble..

black smoke also caused by KO piston ring (what this does mean?).. check the compression

Guys, please let me know your feedback, is it ok if I follow this to tune my engine? Only problem is my AC is not working. So will it be a problem for me to follow these steps since it says that I need AC to be on during the process. Please advise.

Will this help to get a good fuel efficiency and stop black smoke?

[The Stig]

8 hours ago, Danny1997 said:

I have a Lancer CB2 1995 which also has an issue with the carb

The fuel comsumption is very high and only does like 7km/L

The carb had never been tuned or serviced

Current mileage is around 160,000 km

Any reasonable and a qualified mechanic whom i can consult ?

Talk to Mr. Dhammika in cotta road

0112694223

[Russendyll W. Acuna]

 

Thank you a lot for your post. I was able to tune perfectly my lancer piston carbs. more power to you. 

 

[Russendyll W. Acuna]

Thanks for your post. I was able to tune my carb piston perfectly. now my lancer run smoothly. 

Sent 

 

[Randolph]

Hello,

Can someone please recommend a mechanic for tuning a 1988 Ford Laser?, issue is fuel consumption is high.

Thanks and best regards

Randy

[Rumesh88]

At cold start no big issue. It happens when the engine turns hot after some driving. Eco test failed at first time. Then I got the air filter cleaned and adjusted the idle a little bit then got passed. Let say barely passed. CO level is close to 4.0 at idle. At 2500 it is very less 0.2 or something

This means you already had the answer with you. I do not know why our mechs do not make better use of the eco readings. In your case it is not difficult to adjust the carb because you need to get only the idle mixture screw set, but it may not be perhaps possible if the piston fails to home in at idle position due to restricted movement. You can test this if you make sure the car idles at 600 (or whatever stable speed without AC) before you stop the engine after a drive. Now when you restart the engine it should idle at the same stable speed. If u try to rev the engine just before stopping, as many of us got used to, the piston may get stuck at a random position thus giving you trouble when you restart and idle. If you observe this behavior of the carb, get your piston mechanism cleaned so that it moves freely all the way. At the same time get the carb needle too checked for damage.