GAPAUTO

I checked the cable slack which didn't had any problem, actually it has plenty of slack which i think i need to replace the cable soon because the adjuster is in its max . The AC idle up unit is custom unit which was fabricated using a diaphragm since this model didn't came with a original AC. So the idle up is clearly visible and a simple one which i did make sure it didn't had any thing to do with idle. Well the throttle flap seems to be seating when i took the carb out and clean few weeks back. After last evening idle tuning now i need to keep the idle speed adjuster screwed in a bit to have the required amount of idle speed. So probably i was running rich which i guess the reason the idle was not really smooth. And i think probably my timing is ok (Not advanced) from the HC levels in the failed report image. Any more thoughts ?

Well i cleaned up the Carb few weeks ago and fix a part load idle issue as well with the help i got from you on pin pointing the problem. But i think i didn't set the idle mixture after the second round of cleaning. I had a small hikup kind a stumble in idle which i think cause by running rich. Had some carbon around the ring of the spark plugs as well, but plugs were not fouled. I re adjusted the idle mixture today evening and found out i was running idle without event the idle speed adjuster was not even touching the throttle arm . What i did was increase the idle speed, and then started leaning the mixture until the engine run rough. Step back until the roughness stop and Step back less than a quarter turn. Then readjusted the idle speed. This is something i used to do with my old VW Bug which i read from it's manual.

Its a Carb on 4G12 Lancer. Well the Pass Image is my last year result. Still i didn't went for the second attempt.

Hi Guys, I went for a emission test today and it was failing on idle with a high CO value. I'm doubting that i have messed up with the idle mixture and want to get your inputs as well. I'm attaching my existing (Passed) results sheet and the new (Failed) result sheet. Failed Passed In the failed report i think my 2500 RPM seems to be ok other than the indication of low lambda which might be caused by the my airfiler which i will replace before my second try. Please give me your inputs GAP.

No it was actually 5mm. But the i found out that it doesn't belong to emulsion tube since there was no such o-ring in the removed parts. By the way there were some more air passages which has varnish in them and i sprayed them clean. And i have messed up the balls in the pump cylinder and discharge chamber. i had balls in the same side (small size). But after reading some articles about AISAN carbs i found out that the big ball should be in the discharg chamber. And also the small ball in the pump piston chamber was stuck with varnish. After cleaning and fitting it back, now it runs like a kitten . Thanks for all the help Rumesh

I removed the carb today and checked for the port above the plate, and in first spray there was no visibility that the spray came out. but then i close the port below the plat by a finger and sprayed again which made the spray come out of the port above the plate. Another question is the emulsion tube, is there a o-ring ? cause there is a o-ring in the kit i bought but in the old removed parts there was no o-ring with the emulsion tube ?

Yes i just checked it and it just before the primary venturi starts to deliver fuel. This happens until the primary venturi is fully operational. So i guess its the fast idle port which is clogged as you pointed out. Is the fast idle port is above the throttle plate ? And can this be clogged because of the deposits which flowed when i was spraying card cleaner ?

Thanks Rumesh, It happens even when the engine is warmed up. I will check tomorrow as you have mentioned when is the hesitation is actually occurring.

Hi Guys, Recently i did a carburetor cleanup using carb cleaner and changing the JETs and gaskets. I did the same 2 years back and after fitting the carb back the engine ran fine. But this time after fixing the carb the idle seem to run smooth. But when i pickup the car in 1st gear the car stumbles a bit (hesitate) and then returns to the rpm which it should according the throttle position. This only happens at certain angle in the throttle movement as i have notice. But pushing Gas pedal beyond that angle accelerate the engine just fine. What could be the reasons to have such symptoms ? I checked the accelerator pump which seem the work as expected. Engine Model : Mitsubishi 4G12 GAP.

Thanks Davy, Great answer, You answer helped me a lot and showed me a side which i didn't though of about the 3rd option, now i see it not a really good option. I will try the panchikawaththa place first before moving to option 2. GAP.

Hi Guys, I have a 1978 lancer wagon, When i open the rear door it doesn't stay still, the reason is that one of a rods in side the assembly which should keep the weight of the door while its open is broken. I was hoping modify it with small shocks similar to what nowadays cars come with. Has any body in this forum has done such modification to a wagon rear door ? If so can you share the details such as how the new brakets and shocks are fitted and what type of shocks that you used.

Well guys, i was mentioning pinging which some ppl called a spark knock. So as Crosswinds brought up its not some other mechanical noise, well i know that this old engine do sound rough but trust me people who has newer engines in late 90s sounds rougher than me . I mentioned the whether because a engine can start to ping when the intake air is too hot, and it can also happen when timing is bit advance or the mixture is too lean or the octane value issues. So guys now i know that we will not see any difference is type of petrol, i will give try to Euro 3 and i will check upon my mixture and timing. Thanks.

HI guys, I wondering which would be the best 90 octane petrol from the following fuel stations. IOC Cepetco Laugh The reason i'm asking this because currently i'm using IOC, but in this hot whether my engine suddenly start to give a pinning when accelerating. So i wonder its really because of only the weather or the quality of the fuel which adds on to the hot weather. Please share your thoughts and experience. By the way i'm running a 1978 1.4 L Orion Mitsubishi engine. GAP.

Rumesh88, i totally agreee with you. I did face the head and done the value seats as well since they were bad and replace the value guides when rebuilding the engine. i will do a compression test and see as well as you suggested.

This happens even when the engine is hot as well. Well some thing i notice is that as soon as the car is started it runs really fine for few seconds (~ 5secs). Then only the idle get rough. Well its has a EGR value which has two diaphrams, But all hoses are disconnected. I agree with you on some mechs disconnect things because they are lazy to fix . I will check the distributor cap as well, i clean it well , but i didn't check the connection points when they have a good connection. Thats i will check as well. The nice thing is before the engine rebuilt, two of my exhoust values were not even seated well. But the engine didn't have a problem like this, even though it was bit rough on idle and fuel consumption was high but not like this .

Thanks every one valueable comments, I went to the same mach today and he checked the values (even though i have made around 600km after rebuild) for clearence. He adjust once value which needed to adjusted and when we fireup the engine the miss was still there. Then he checked for vacume leaks in intake manifold and check the EGR value as well. It has been blocked by the previouse owner and it should not be a problem since its blocked. Then he checked the points and adjust it a bit by making the gap bit larger. It seems that in one coner the gap was not enough. Now the idle was much better after that. But still i feel there is a slight different how my engine idles . i'm wonder wehther i should chnage the points and the condenser

This car didn't came with a factory fitted AC unit, So there are no AC dampers in Carb. I checked the idle screw and the mixture screw. Both seems to be fine. Even if i raise the idle speed by the idle screw (the one which adjust the throttle possition) i can feel a light miss in the engine. I'm afraid whether its a sticking value as metioned in the above reply . How can i checked that without taking the head off ? And what about the condenser and points ?

Yes did that, And the plugs seems be fine no carbon deposits, they have a brownish color. In the rebuild process i replace the value guides and new plugs was installed to trouble shoot this problem.

I have a Lancer wagon which has a 4G12 enigine. Two months back i have rebuild the engine by changing bearings ,cylynder rings , oil seals and valve seats and guides. Last week i droves the car which didn't have any problem. But yday when i started the engine it was rough and from the sound it seems like one cylinder was missfiring. When i rev the engine the missfiring sound goes a way. I tried removing one plug wire at time to check which was missfiring and it seem the 1 and 2 were not firing as it should be. Change the plugins and checked the wires by replacing them with another set i had extra. But it seems those are not the problem. When i remove the wire half way on cylinder 1 and 2 i can here the spark which is jumping from wire to connection in the plug. I checked for vacume leaks and intake manufold mounting points on the head as well. Check the value clearence last week at the garage and they were ok as well. So could this be a problem with my platinum points or the condenser ? Or is it a problem with fuel delivery or mixture ?

i had the exact same problem in my 4G12 Lancer wagon. And replacing the oil pressure switch solved it. Its start when the oil is heated up. Try replacing it cause it not that much of expensive as i remember.

Hi, I did the anual emission gas test today. The results where as follows. ----------------HC----CO-------LAMBDA----O2------CO2-----Wastage 605RPM-----586---3.436----0.972--------1.88----11.81-----12.11 2500RPM---349---4.013----0.921---------0.92----12.3------12.12 My engine is a Mitsubishi 4G12. Its a lancer wagon. When i normally take off after idle there is a whitish smoke coming out and my air filter is 1.5 years old as well. Can some one explain me whether this is some thing to do with timing or carb tuning. Thanks in advance. GAP

Thanks a lot , i knew that it's condensation of vapor which is a outcome of the combustion, but i wanted to get a second opinion from a expert who can confirm the tuned state. I will try to track the fuel economy and see whether it has improved as well .

When I start my car in morning there are water droplets in the tailpipe. This started after the last Carb tune up. This goes away when tailpipe heats up. Does this mean that the Carb is running with a optimum mixture? GAP.

Hi Rameez, He is in the Ganemulla road in kadawatha. There is a narrow double bend which is called "Aliya Wanguwa" after that just ask for "Nimal's Tinkering Place" from some one. The garage is next to a bakery.

Well i'm not sure to where you are heading here, but all i wanted is to get an idea regardless of the amount i paid already. This is some thing fo future reference a kind of lesson learn. So i guess its better we stop this "paying the 1500 thing" .