Hi,
I was change my car (P.Wira 1.5A 1997)carburetor from original "Aisan" to "Mikuni Corp". I get this carburetor from my friend in Australia, the carburetor coming with all hose, wiring, ECU, manifold and etc.
I installed in my car last week, the result so far its good but because i haven finish doing all wiring and tuning i haven get best performance from it.
I was try to ask my question in other forum but no body reply me till i find this forum and hope to get reply.
Here i am looking to know how to do tuning this carburetor?
How the ECU wiring diagram looks like?
And hose vacuum how they works?
unfortunately i am not sure this carburetor model or was for what kind of car before, by searching on internet i thought is for Mitsubishi Magna but which model i haven know it. hope here i can get more information and guide.

Thanks an advance.

Mitsubishi Sigma/Scorpion/Magnas from the 80's and early 90's used Mikuni carbs on their 4cyl engines.
They were used on 2.0L and 2.6L engines and may have been used on the earlier 1.6L engines.

Could you post a picture of it so we can see if it is vaguely similar to anything used on a Mitsubishi?

Thanks for your prompt reply.
here you are few pictures of this carburetor.
http://img98.imageshack.us/img98/3930/1002783q.jpg
http://img225.imageshack.us/img225/3158/1002797c.jpg
http://img163.imageshack.us/img163/9521/1002785m.jpg
http://img830.imageshack.us/img830/4506/1002784u.jpg

----
http://imageshack.us/photo/my-images/225/1002797c.jpg
http://imageshack.us/photo/my-images/98/1002783q.jpg
http://imageshack.us/photo/my-images/163/1002785m.jpg
http://imageshack.us/photo/my-images/830/1002784u.jpg

is the gearbox auto or manual
float level is non adjustable

pic 3 ....92 is the factory idle jet

the dash pots fail sometimes and they need to be checked

question what idle speed have you set your carby at ?

extra wiring is for an auto TCU unit needed for the throttle position sensor
choke set up is easy

http://i253.photobucket.com/albums/hh59/magnabuff/tn20carby20auto.jpg
http://i253.photobucket.com/albums/hh59/magnabuff/emission_152-2.jpg
http://i253.photobucket.com/albums/hh59/magnabuff/1.jpg

http://i253.photobucket.com/albums/hh59/magnabuff/carb.jpg

ive had mine rebuilt a fue weeks agow, went to the wreckers and non of the 8 i saw wrere the same yet all from a tn magna.

Hi and thanks for your post,
1-The gear is auto.
2-I didn't adjust/tune the carb because i don't know how to do, even here the mechanics also don't know how to do!
3-first start in morning get 1300r/min till engine warm up, 850r/min and 900r/min with A/C when engine warmed, 110km @ 3500r/min and i was try up to 160km @5000r/min which is already illegal here, here max speed is 110km only!
4-May i know more about "TCU" please?
This carb coming with one unit control which i thought is ECU, and i hope to find how to do the wiring because all the output from the unit already plugged but input wires was cut before i get and i didn't figure how to do! only negative, positive and RPM wire done!
------
My problems are:
1. Morning or when engine is cold engine produce black smoke about one min (even with new plug "Bosch spark plugs 4 electrodes")
2. My car after change to this carb is poor fuel economy (high fuel consumption) 11.5L for 100Km!
3. And at the end a lots of cut wire haven install!

the TCU (Transmission Control Unit) is the computer that controls your automatic transmission and tells it when to shift gears and at what speeds. it relies on input from the TPS (Throttle Position Sensor) which tells it how far open the throttle is and pulses from the distributor telling it how fast the engine is running. the main way it connects to the carby is through the TPS which is mounted on the carby and would be one of the sets of wires on there. (not sure what ones)

the problems with black smoke and poor fuel economy sound like a choke that isnt working correctly. check to see if the choke completely opens when the car is warm. the choke is the nearest plate to the top that blocks the carby passage towards the back side of the carby. if this does not fully open then the mixture will become richer and thus produce black smoke and use more fuel. could also be running too rich because its tuned for a bigger capacity engine. ie letting in more fuel then needed.

test the choke first however.

regards jay

Is th TCU under the carpet in the
front middle
you may have to use your own TCU
and your car its engine bay wiring loom

the TCU have would be for a magna gearbox

I dont know anyone who would have the exact wiring diagrams for the
carby to TCU for you

sounds like a job for a qualified auto electrician

could also be running too rich because its tuned for a bigger capacity engine. ie letting in more fuel then needed.

I was thinking that the carby would probably need to be jetted to work efficiently with that engine.

Black smoke for a minute on cold startup is fairly normal because that's when the choke is on. A rich mixture will only exacerbate this. You might be right that the choke is not coming off (it's been known to happen before) but in that case wouldn't the smoke stay black for a lot longer than a minute?
The idle sounds a bit high for a Sigma 2.6 but because you're using a completely different engine this might be normal.

This is a dual throat carby, so at full throttle it'll open up the second throat and blow out your fuel bill.

Also, Edanny101, we don't want to know about your illegal speed tests.

Hi and thanks a lot for your kind replies.
i toke few pictures and show as below.
No.1) Carby during engine warm up.

http://i1081.photobucket.com/albums/j351/edanny101/th_01.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=01.jpg)

No.2) I would like to know more about this 3 adjust screw. Screw1 when open engine very power and when close engine no power at all but no change at RPM meter when change adjust. screw 2 i think is idle adjust and screw 3 no idea.

http://i1081.photobucket.com/albums/j351/edanny101/th_03.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=03.jpg)

No.3) Plug 1 i was attached the A/C, is it correct? plug 2 attached to the TCU wires and plug 3 i was attached my original distributor wires, is not correct right? the X mark added by myself because 4g15 engine distributor has only one hose and both mikuni carby hose join to one.

http://i1081.photobucket.com/albums/j351/edanny101/th_02.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=02.jpg)

No.4) Here is all wiring, all my problems is at the point which marked by "?"

http://i1081.photobucket.com/albums/j351/edanny101/th_04.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=04.jpg)

No.5) The unit pictures and wires

http://i1081.photobucket.com/albums/j351/edanny101/th_05.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=05.jpg)



old magna, thanks for information about TCU, would you please guide me how to adjust the chock.

magna buff, Thanks for the link, i am going to study my bits. if i need help about them i will back to you.

XiLurk, thanks for post, may i know how to "Jetted"?
About the smoke i also surprise why is very short "less than one min even can say about 10 sec"! not long to say chock not coming off!
Idle, i think its ok for my engine.
Fuel bill! so it can not be more economy, is it?
And i am sorry for my bad English, i really apologize, by that illegal i mean i don't have chance to test my top speed.

pictures links:
http://i1081.photobucket.com/albums/j351/edanny101/01.jpg
http://i1081.photobucket.com/albums/j351/edanny101/02.jpg
http://i1081.photobucket.com/albums/j351/edanny101/03.jpg
http://i1081.photobucket.com/albums/j351/edanny101/04.jpg
http://i1081.photobucket.com/albums/j351/edanny101/05.jpg

old magna, when i installed this carby, my auto gearbox change at 4000~5000 RPM! i thought because the auto gearbox shift point is not optimum and i try to adjust by opening throttle lever nut! but now after hear about TCU i consider that problem maybe because i didn't done the TCU wiring! can be?

magna buff, My car is Proton Wira with Mitsubishi carby 4g15 engine auto gear 3-speed AT (F3A21) . I didn't find any TCU in my car before this new carby, i was try to ask few mechanics here but they just laughing on me! looks big job for TCU wiring.

What I notice on this is in the picture that says 'warmed up' the choke plate is not fully open. It's still at a slight angle, fully warmed up that Choke plate should be flat Virtical not at a 5 or so degree angle.. This will be effecting your Mileage.

edit: No 2. is your AC idle screw.. it adjusts the Carbies Idle when the AC is turned on.

To get the choke right btw, at 23 Degree's Ambiant Temprature (roughly) the Mark on the Auto Choke Arm and the mark on the Green Cog should be in alignment. Of course you may need to adjust both the choke and the Pinon plate a little (using the choke adjustment screw and the Pinon plate adjustment screw).

The other problem may be that the Carbie needs to be rebuilt ie it's needle and seats all replaced/cleaned, new gaskets etc etc.. You are talking a 25 year old piece of Machinary there ;)

As for TCU wiring on your transmission.....

on an actual magna you would find it slightly to the left and down from the AT Fluid Dipstick , the plug your after it's normally a white plug going into the front Transaxle gear box (I can say this I just took my entire front end apart on a TN auto and put it back togeather with a new engine ;) ).

On yours I'd start looking in the same place.

Thanks Dear Robgraham for nice explanation .

May i ask which and where are choke and Pinon adjustment screws ?

In the picture of carby uploaded by "magna buff" point a screw for choke adjustment, i was try in my carby but its not turn and i afraid to break.

The TCU wiring is difficult because my gear box is different, No speed sensor, No oil temperature, No pulse generate and etc. But the carby wiring almost done except two.(No.1 and No.3 in the picture)

http://i1081.photobucket.com/albums/j351/edanny101/th_02.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=02.jpg)

The No.1 I connected to A/C but No.3 still unplug and think it effect vacuum system.

hope to find this TCU wiring diagram, My TCU number is :
MD 148064
E2T52771
OZ11

i found the best way
to get the choke adjustment right

is to unto the little nut on the thread small 4 or 5 mm spanner i think
then take the choke screw all the way out
clean off the locktight

then screw back in to adjust the choke

Dear magna buff,

Thanks, I screw the choke screw all the way out and after clean, screw it back and when engine is in ideal temperature i adjust the choke in all open. Show as below picture.

http://i1081.photobucket.com/albums/j351/edanny101/th_DSC00011.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=DSC00011.jpg)

Tomorrow i am going to test my car; black smoke in cold start and mileage, hope can see the different and i will update here.

Thanks again.

Hi,
By the first, I should thanks all of you for kind helps. Shearing your knowledge and experience helped me finally adjust the choke, solve black smoke and better fuel consumption.

Here i would like to ask about other adjustment screw. In the below picture numbers "83, 86, 89, 92 and 94" marked by red circle.

http://i1081.photobucket.com/albums/j351/edanny101/th_00012.jpg (http://s1081.photobucket.com/albums/j351/edanny101/?action=view&current=00012.jpg)


What are they jobs, What are they effects when open or close,How many mm need to be screw in or out. How they work and each screw related to which part of the carby?

Thanks again

92 is the factory setting

I found that 3 and a half turns out
from fully scered in
is the factory setting

just make sure the shaft isnt bent or damaged

92 is the factory setting

I found that 3 and a half turns out
from fully scered in
is the factory setting

just make sure the shaft isnt bent or damaged


Dear magna buff,

By apologizing, i didn't understand your meaning for "that 3"

And how can i check the shaft is not bent or damaged?

Thanks.

using a thin flat screwdriver

three full turns and a half a turn of the screw you count them

from all the way in

inspection is by looking at the pionty end

its called a jet