my proton wira aeroback 1.5 auto have this problem recently...i start the car for a while then the engine stall
so i went to mechanic and ask him to clean the throttle body, check the air filter...then when he put everything back and tune it with a computer device he said the circuit board in the throttle body going to spoil already...so he advised me to wait until it complete gone then change a new one....

my question is which circuit board he's referring to ? i ask him izzit to throttle body that he clean b4 that...see this picture
http://www.hitachi-hap.com/products/Control_Units/etcu.jpg
or something else bcos i didnt see any circuit board on it

if that's the one i want to know the price range for a reliable/performance brand other than proton...

personally i dun feel like waiting for the thing to die out...so i want to change it asap

unfortunately, that's the only brand of throttle body u can use. it's a common problem. just clean the throttle body everytime u service the car. it should be fine.

ohh i went to eon service center they said it's the servo motor that need to be changed...he said their brand is apm

izzit good? any other reliable brand and cheaper
the price they charge is 600 including service

other than cleaning, there's some plastic gears inside the TB that could be changed....it's cheap, rm30+ i think...any reliable normal garage can install this i think

i did this to my satria years back for erratic rpm behaviour of my engine...not sure if this could solve your problem, but it's worth a try.

Just got back servicing the throttle body too. Before with aircond on 1 oso engine can die.

Ask the mech to air blow the connecting hosts...they could be clogged. Mine is running fine now. Aircond on 3 also never jerk. Gonna fill in and see fuel consumption. I think it will gimme alil bit more milage.

it doesnt matter whether u on 1 2 or 3..
if u on 1 and the car jerk, then 2 and 3 confirm jerk
if u on 1 and no jerk, then confirm 2 and 3 wont jerk
experienced from my own car

Ic...in my case if i was on 1 my car jerk less than 2 or 3.

mayb we got diffrent problem

tumpang thread...
if stepper motor is not working, does it have any effect on the car?

ur car idling will fluctuate..
from 1k to 0.5k and so on..
when idling also will get severe vibration..
when u r cruising, sometimes the rev will drop and rise back in few seconds time, result in short term power loss

ok confirm that the ics servo motor circuit spoil
already check with 3 different garage...all also got use computer board to check

right now my car will stall during starting up...so have to step on the acc. and according to mechanic that is the only effect and if worse will stall when not moving...

This post has been edited by triads418: Mar 24 2008, 08:32 PM

what car are u driving? with what engine?

u can get a 1.6 throttle body for rm400.00............good for slightly more power on the 1.5....

wira aeroback 1.6 xli...there is 1.6 xli logo on the car body..so i think my car should be 1.6L

one of my mechanic said the servo motor should be rm700 anything less is refurbished product...2nd hand around 300-400 also warranty 7 days

YES Ur car is a 1.6
the 2nd hand price is more or less the amount u posted, new 1 is very expensive

1.6, use perdana 4 cylinder throttle body. re-con ones will cost u rm450.00. more power

what is the difference...intake hole bigger? if more air comes in does that mean more fuel will be injected?

i dont mind changing it to gain more performance as long as its fuel consumption is the same as b4...

Your throttle response will be better~~
negligible difference on FC but if u always hentam....the FC will be higher as usual...

This post has been edited by shinjite: Mar 26 2008, 11:29 AM

err....just want to ask sifu here...mine is wira 1.3 injection and using mmc wiring...beside 1.3 TB what other TB can i use?? is it possible i use 4GX series TB?? sorry for noob question

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Added on March 26, 2008, 11:41 ambtw, seem my rpm always fluctuate like crazy sometimes it might goes to 2k rpm....when i stop at traffic light the rpm will always keeps fluctuate and people might think that i play2 with gas pedal....really ashamed..

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Added on March 26, 2008, 11:42 amis it stepper motor problem?? this is my second TB...and its really costly to change..

This post has been edited by ezianevo: Mar 26 2008, 11:42 AM

the only 4g9x that u can use comes from the wira 1.6. the perdana one is too big....


sounds like a stepper motor problem

thanks for the feedback...
the good thing is that no problemo with idling.
But stepper value is 0 always. After cleaning TB & induction box, my car maintains 900rpm no A/C. 300-400rpm on A/C & no fluctuate, fortunately. I'll just attempt clean stepper motor later on see any good results.

perdana one is same with FTO? 63mm?

perdana is 60mm.

no offence bro, for a TB, i think better spend on a new one rather than a recon one. recon ones already cost that much, might as well spend a lil bit more on a new.

New 1 alone will be twice the amount....

then u might want to use FICD (or FCID?) to stabilize ur car idling when a/c on

wira new VDO still can get in a range of 600-700.

Thats for VDO, not Mitsubishi ones

hi triads418,

I'm driving proton wira1.5 manual year 2000 car. I change the entire new genuine Throttle Body since last week. According the mech in the proton service shop, he said the proton 1st version that have fuel injection function (1998 ~ 2000) proton car always cannot solve the RPM problem. Those 2001 ~ onwards can try to solve by clean and servicing by TB gear kits.

i spend Rm980++ for new TB tuning and labour cost.

My problem is RPM drop until 500 if aircorn pump is run. If without air corn pump run the RPM is ok. When RPM drop to 500 whole car shaking like earth quake.

Hope this can forever solve this problem coz my car already almost 8 years and hope can drive another 8 years. But so far the 1st week now my car can feel good . Still have just abit shaking and plan to change 1 set new mounting to resolve the problem later.

Hmmm...he said can't solve the bad idling with air cond on?
Like that we changed to genuine new TB also useless?

What I usually recommend for all Proton throttle body '"Earthquake' problem; buy 1no used Toyota air-cond adjustable/ATC, drill & tap a hole at inlet manifold, hook-up the vacuum pipe & problem all solve FOREVER. Can set whatever idling rpm you want.

I had installed Toyota FICD, but my rpm still drops when air cond on

dun need to drill hole lah...

Better-lol, after BOCOR-BOCOR rpm too high pulak.

hi....
i do owned a perdana 16V model & its been 10 year......
now my car got a problem like wat u all mentioned above,
which is throttle body problem, always "earthquake" when da car is idling or halt....
sometimes it even when stalled....
consulted several workshop.....these wat i tried.....

been changed many time those tiny gears which fitted inside TB.....
they're wont last long......then changed whole TB wit recond set.......
after 3 month, problem start to occured......
fedup with same thing.....straightaway get brand new TB from proton.....guess wat?
it costed RM1.2K for a new 1.......after used 1 year.....its back again....

then decided to try other workshop,

first thing, they said it was spark plug worn out so changed it....eventually it solved...
after 2-3 month....problem arise again....changed another brand new set plug...
after 2-3 month...same thing again....

went bac that workshop, check again.....detected 1 of the 4 plug cable not working properly....
replaced new set of plug cable.....as it come only whole set not separate....
then thought it was settled down......barely 1 week......same problem again....
but it wasn't that worst till stalled,still drive-able....

now i began noticed, below TB there is area got several electronic cable attached/connect to TB...
that area fully wet with dark oil......is that sign happened to u all proton car?
b4 this it that area are dry not wet......

This post has been edited by Klemann C: Aug 16 2008, 12:35 AM

that's a sign that the throttle body spoilt......

so its that any possibility to fix bac TB witout change whole TB??
coz this TB i juz used not more than 2 year....

full service and clean your TB

how much to do TB cleaning?...
im using waja 1.6 A 2002...
never done TB cleaining since bought...
where i suppose to send my car for cleaning purpose?

Just make the mods as I've explain 'aboved', cost less than $300, after that non of those fellas with the problem ever come back again.

thats the ISC cable.... inside ISC is the gears and grease to lubricate it.... mayb the rubber gasket sealing that part KO adi.... grease/oil leaked out, causing wear n tear to the gears....

or another possibility, ISC cable melted due to extreme heat...

I am facing the same TB prob for my wira 1.6xli, and recommended shops near PJ?

I heard this is a common problem among wira/satria owners.

I myself having throttle body problems too. The gear inside the throttle body broke and after changed still the same problem which is the RPM go up and down even though I didn't press the accelerator. So mechanic asked me to change throttle body. I got myself a 1.5 model for my 1.3 model which the mechanic said should be compatible. That throttle body didn't come with a gasket so the mechanic made 1 himself.

Ok so everything went well, the RPM doesn't go up and down anymore, but the engine will subsequently die in a sudden. No warning no anything, just die. Also after changing the throttle body so many problems jor.. Even my CHECK ENGINE lights are all gone. Stupid mechanic ar~~ More problems after changing throttle body.

that gasket didnt sell as separate unit in sparepart shop??...

my car had this kind of problem before, so what i did was go to kedai potong get myself a good TB with good condition isc motor, my car is 4g15 injection but i bought myself a 4g63 TB(RM250),throttle response increased significantly not to mention reduction in FC. but still after two years, the ISC melted again so since i can't upgrade to even bigger TB, i just went to workshop and installed an additional toyota ficd, it cost me just rm150 including labour and now the probelm is fully solved.

I got the throttle body from distrobutor in my hometown. No gasket included.. I was too rush when I bought the throttle body that I forgot to check whether there's gasket included or even sold seperately. The price where I bought the throttle body was rm300+ only whereas the mechanic wanted to sell to me for RM500+. The mechanic told me he can make it himself then I didn't bother to buy it.

But thinking thoroughly, I can already get a 2nd hand stock Wira 1.5 engine with near the same amount of money. (RM500 for Wira stock 1.5 engine without installation)

rm150 jz for the toyota ficd??... whoa.... last time i bought from halfcut shop for rm50 only... diy install, free....

now cannot get adi lor... 4g15 enjin lantai cost more than rm1k now...

@ sonic-U've been con la bro..FICD paling mahal pun only cost RM 50 + RM 30 for installation

This post has been edited by aliftaufiq: Aug 18 2008, 09:01 AM

Mine during cold start got problems 1, rpm 1.5k, then when u drive a bit for round 10 minutes
The rpm will go up and down up and down. Need to off engine and reignite back then drop to normal 900rpm idle. I already installed FICD still like that >_>

If want to use Toyota FICD than you need to do some mods within your current throttle plastic gears. That alone would recommend to install the drill & tap one directly to the main throttle chamber so as it's distributed to all cyclinders without any possible air-leaks, no cars which have been installed with this current method that I've known of ever had a recurrent of this problem. But some will want to maintain without mods & this is what has been done for its maintainence;

remove throttle-body magnet & do a service every 10K km, by cleaning with non-solvent base cleaners, water base ones & compressed air. Do not use anything like petrol or any alcohol base as it will damage the plastic components. After that apply the cleanest & best water base grease/lubricant that money can buy no other than 'KY' which can be obtain from pharmacy. Seal the item again with silicone liquid gasket & it'll perform as per new until the next service interval. So far so good for my mates.

hi.....can anyone recommend me a workshop which does provide addon FICD thing?? with reasonable price?
i wana fix my car, add FICD on throttle body....now it gettin worsen....car moving also can stalled....serious
somewhere near old klang road or within kl area?

i went to proton authorised service centre, they dun provide service to tb......only change to whole set brand new 1!!! that fella talk wit lcly la....
anyone got recommendation,pls PM me detail....need to fix it ASAP....everyday need to use that car
thanks in advance!!

Thats what u get if u go authorised SC, they will tell u TB rosak, change enw 1, costs a bomb

Just go normal workshop and tell them u wanna install FICD, kao tim

changed my Wira 1.6A XLI throttle body after it died of 8yrs of usage.

Costs me rm170 like tat

ok....but i did asked several workshop.....they said no wor.....even ask them juz service also "like force them to take poison pill"
btw, which step more recommended?

1) juz service & clean TB?
or
2) straightaway add FICD on it?

as i did mentioned b4,da throttle body ISC cable there is covered with dirty dark color oil...
1 of the forummer said, that sign showed TB gonna spoilt

hmm tumpang guys, my tb now starting from cold start would be 900, then after running for like 10 mins it will be 1.4k or sometimes 1.5k. it didnt drop and increase again its like constantly 1.5k already >< why is it like that?

dat day i went my local sparepart shop enquire about ISC repair kit... he said now they came up with an easier solution...





it bolts directly to the throttle body, replacing this unit...





the ISC socket still plugs in, but with removal of coolant lines inside the throttle body... it works the same with less damage coz heated coolant no longer flows into the throttle body.... but somehow, the thing is still made of plastic and will melt, as what often happens to faulty throttle bodies... this stuff cost rm150, can easily diy change, if u know how to remove the throttle body urself....



this is what conventional ISC repair kit consist of... plastic gears inside the ISC... if the bottom black plastic thing melts, changing this alone wont help...




or else, jz custom a metal/aluminum plate and block the whole thing off and use FICD to control ur a/c idle rpm...

Allright, I'm not a mechanic by trade, but I've worked on cars enough to know that some of the solutions offered here will do your car more harm than good.

That "FICD" posted above is a Vacuum Switched Valve (VSV) that opens up whenever +12V is applied to it. VSVs are used for EVAP and EGR control, *NOT* for idle control. All it does in this instance create an air bypass from your intake straight into the manifold. Wiring it up to your A/C compressor will cause your idle to go up to 1.5k - 2k RPM. There is no form of idle "control" here. In EFI engines, this will kill your fuel consumption and cause other issues like your car jerking/surging forward when you release your brake pedal, or even cause shifting issues if you have an auto transmission. This is because your ECU is no longer able to properly control the idle and will think you have a vacuum leak.I know some people are going to flame me for this, saying there are no issues with this setup, but trust me, this would cost manufacturers at most $5 to implement, and if it were this simple they would. Car manufacturers know more than you about their own engines. This "FICD" is not intended to supplement or replace your engine's idle control method. If your car wasn't designed with one, you shouldn't be using it.



^ This is the device that Toyota uses to control idle. It's called an Idle Air Control (IAC) valve. It contains a stepper motor that is controlled by the ECU to vary the amount of air going into the engine to control idle. If you turn your A/C on, your ECU tells the IAC to open a little more to increase idle to compensate. Newer cars that have drive-by-wire/electronic throttle control may not have this as the ECU controls the idle by directly adjusting the throttle valve. This is also partially the reason why certain D-B-W cars accelerate very suddenly with slight movement of the throttle pedal - because the throttle butterfly is already partially open.

If you have an idle problem, fix the cause at the source.



Fluctuating idle can be caused by a plethora of problems from a dirty throttle body/IAC to electrical issues. I have a feeling you may have electrical issues on yours.

Most cars, when first started up, will idle slightly higher than normal for several minutes to warm the engine up. This is needed mainly to lower emissions, but also because every modern engine is designed with an optimum operating temperature range. Catalytic converters also require warming up to work efficiently, as does your engine oil as it's viscosity lowers as it warms up.

If your idle keeps fluctuating, you could have a faulty coolant temperature sensor. I would also check the AFM/MAF/MAP (whatever you have on your car - all does the same job, measure air volume) and the oxygen sensor (on your exhaust manifold/header pipe) in case one of them is causing your car to run in open loop. It can also be something as simple as a dirty throttle body to something nasty like a faulty ECU. I'd get the car checked by a mechanic who knows what he's doing.



For the love of God, do NOT seal your throttle body with silicone/RTV/FIPG, they are to be used as gaskets in oil pans and valve covers where hot oil is an issue, NOT throttle bodies. It is a b*tch to remove; your mechanic will hate you and will scratch the hell out of your throttle body trying to clean it all off.

-------------------------------------------------------------

Throttle bodies / IACs / intake pipes will get dirty, this is normal. Your engine burns fuel, and carbon is a by product. This is also why your oil goes black, it's normal. Throttle bodies and IACs *should* be cleaned regularly, though most mechanics will not look at it until there is an issue with the car. It can be time consuming as to clean it properly requires removal of the TB, intake hose, disconnecting all the cables and hoses, etc etc. Some TBs also have coolant bypasses in them, and you need to top up the coolant after reinstalling the TB.

If your issue is caused by a dirty TB/IAC, clean it. Do not install the "FICD". If you're feeling poor, do it yourself. All you need is carby cleaner, a socket and ratchet set, a few old rags/t-shirts and patience. Alternatively if you're lazy, buy yourself a bottle of Seafoam and run it through a vacuum hose.

I totally agree with skyther. thats what happens to my everyday used wira 1.6(A) year 2000. I've installed the FICD, but new problems occured like you mentioned it above... jerking, fuel consumption, the rpm... all gone mad already. Plan to pull off the FICD and start find new TB. My mecha said, the plastic below the TB already melting. I've service it by change the servo kit... but same problems still occured.

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Added on August 25, 2010, 10:37 amMine also have the same problem. Rpm will fluctuate when idle and when press fuel pedal i could feel the noise something like sysss sound. What is this actually??
Went to Toyota SC and they scanned, found error at ISC/IAC valve and suggest to change ISC. Very costly.RM1644.

They also said if i'm not change maybe it could effect ECU. Is it true? Please help!

Other thing is my airbag and engine check light doesn't function at all. They said it could be short circuit because of 'cara tukar bateri salah.'

Sorry for my English.

This post has been edited by hleb24: Aug 25 2010, 12:13 PM

it is not ICU (ICU is Hospital term), the correct is ECU. Perhaps you can get a used throttle body at half cut shop at few hundreds.

..the symptom stated by ur posted i kena all..when release throttle pedal..car feel jerk a while..but installed a FICD is the only way to solve my idling problem..coz my ISC is melted..the only way is change throttle body? btw..i am driving an iswara convert to injeksen and i did not connected the ISC socket and use FICD.

My car now facing the RPM fluctuate when my air-cond is turning off, but when my air-cond switch on to the MAX level and the RPM will stable back to normal .. I have done the Servo gear replacing and TB cleaning .. so what seems to be the problem .. unless alternative solution is to replacing the ISC unit ? or just change a recond TB will do ..

hi guys,

i am a lady girl who really dont know much about car..just know to drive..XD

recently my kenari car dashboard appear the " teapot" light, which is the engine light, meaning that something wrong over there. i am also experience the "earthquake" during the car is idle..so i sent it to perodua SC for inspection.

the mechanic told me that the motor inside my kenari's throttle body was spoiled, need to change a new one, which will cost me about RM700 ++++

so guys, could anyone suggest me a cheaper way of solving it?
a)send it to normal workshop and repair?
b) change FICD as suggest by some forumers( i really duno wht is that)
c) or others????

Please help!!!

i will suggest u to repair ur throttle body or rather change a new one but not with FICD..
FICD cannot use with ISC..ue idling will become unstable...

teapot means check engine oil level or low on oil pressure... should be nothing to do with ur throttle body... check ur engine oil level first...

I'm also facing this problem with my 9 year old Satria. After went to mechanic, cleaned up the TB & checked if the servo gears teeth are broken or whatnot, seemed that they are fine. My mechanic advised me to get a new TB but if i want to continue to use the same TB, no issue but my FC may go up a bit.

Currently my TB will somewhat "auto-throttle" if my speed is dropping to 10kmh, auto-throttle my car back to max 30kmh at gear 2 or gear 3, without me STEPPING on the accelerator. Also, when idle, the TB will sometimes light-revving my engine, sometimes causing drivers to race with me at traffic lights, even though that wasn't my intention to rev for racing in the first place. hehehe!

I don't mind this condition, as long as my car doesn't stall or heavy jerks during idle. But truthfully, do i really need to change my TB?

This post has been edited by Zaryl: Jan 18 2011, 05:17 PM

nope u dont need to change ur throttle body... if u dont wanna spend so much servicing ur ISC gears, use FICD... as for ur unstable idling, remove ur throttle body and clean it thoroughly... change new throttle body gasket to prevent manifold leak... check and replace (if necessary) the plastic idle screw nipple...

agree. please check these things:
- engine oil level: if oil level is low, top up. if it's time for oil change, get it serviced (regular service which is change engine oil and oil filter)

- engine oil pressure: suspect that oil pump breakdown/jammed

how can i install this into 2000years wira 1.5 (A)?is it suit for this type of car?

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Added on June 26, 2011, 1:00 pmhow can i install this into years2000 wira auto? is suitable for this type of car?

This post has been edited by zendachoo: Jun 26 2011, 01:00 PM

no. not a plug and play item.....

then how to do it and the cost about all item?got instruction?

best to just get another throttle body.no point going through all that trouble......

This is a common problem for wira. I can list out the problem generally experience by driver and reply from the workshop.


Most workshop will ask the driver to replace the whole thing when they see the black rubber thing is melting. Some claim the motherboard in it got problem but never able to explain what extact problem. Some will say the engine temperature is too hot thats why it melt.

But however I can give you the reason why the back thing is melting. It happen usually when your plastic gearing get stuck, that is where your engine having idealing problem. when the gearing broke, it stuck the motor from running, but the ECU keep sending the motor to run, it will overheat after a while. There is no motherboard inside the black thing it just a wiring, 7 silver wiring in it. Imagine if you claim the motor shaft and you supply current to force the motor turn. what will happen , smoke from the motor right, and sometime smoke from the wiring too...

because the motor stuck, the wire inside the black thing become overheat and it melt the rubber.

the only preventive solution is service the the gearing regularly. because after sometime the grease inside the gearing come stickly. it create more pressure to the motor. It is more stickly early in the morning when u start you car.... and this is where the time is get over heat before then engine warm up.

Get a workshop that can service this for you... to my suprise, even proton service centre not able to do that..... and they not even know that need to be service....

my throttle body black rubber melt d.. is it mean that the wire inside it also melt d? actually what is the function of that socket? can i just replace that part or need to replace the whole ISC?

Your idling got problem? If no problem just use it till got problem.

ISC have to be replaced as whole, they didn't sell it by parts.

not really got problem.. previously it keep stall when i start the car and the rpm drop a lot till <200rpm when turn on aircond, so i bought a recond throttle body.. but after install more worst, it keep on rev up and down.. then i install back the old 1, but i gatal and open the ISC gear to see. nothing broken inside. so after install b, it become normal like last time pula.. so i sell off the recond 1 after i change with the shop. although it wont rev up and down, but when on aircond it drop a lot also ( better compare to before) about 400rpm.. my problem is now it wont rev up to warm up engine at morning.. can it be solved by tuning? or just unplug battery to reset the ECU?

That unit is to control the idling. If damaged idling drops when air con cuts in.....

Try service/change my TB gear, believe me it easy. Mad idling gone already.

This post has been edited by Ashtrix: Jan 16 2012, 11:28 AM


Attached thumbnail(s)

This morning I experience flunctuatin idle, wild, it will like earthquake, stall. and, when i WOT, it can suddenly jerk, like the throttle closed entirely.

I drive wira 1.6sohc. I tried to clean TB myself once using petrol. But during the installation etc, i broke the isc socket (crack on the cover), like, cause its covered with greasy thing, i was not sure that was a melted socket, or grease. So, i pulled pretty hard and it got a crack now. Will it be a problem? When i got my car, already got FCID installed. Should i remove it?

So what should i do? What could go wrong? Possibly ISC? and by the way, how to check whether stepper motor functioning? air flow senser function? Thanks guys.

same case with my SEG..the RPM meter up and down like eartquake M/C call what? I think the stepper NG..

This post has been edited by Arsenalism: Mar 25 2012, 08:14 PM

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Added on September 20, 2012, 6:57 amHi,

I am also using the wira 1.5 auto that perhaps uses the same part as yours.

I had problem with this throttle for many years and had been keep on changing it. I had came to a point where I was
truly not convince with foreman who are not electronically sound.

I came to a point I started to check on it myself.

So I started to use an electronic scope to diagnose all the throttle pin and all signal goes according as expected. But
occasionally the system still failed.

Finally I manage to figure out that the ECU (Electronic Control Unit) will stop controlling the throttle body once it loses
any signal from the throttle body. It will only control it back once you restart your engine.

Let me share with you how it works.

1. Once to turn ON the ignition key (without starting) , you should hear a SOUND like 'he he ta ta ta tak'. This is the
most important clue telling you that the ECU is calibrating the throttle body opening valve angle. Try again you
will find it happen everytime.
2. If step 1 happens each time, this means that your ECU and throttle are communicating and it should work.
3. Start your engine NOW. Then after a while try turn ON the air-con. You should see the RPM rises (abt 0.5sec)
before you aircon physically turn ON. This means that the ECU is working properly.
4. When you turn OFF, the aircon, the RPM should rise first and then drop back to the point when you starting your
car.
5. Slightly engage the gear (ie N to D) making the lamp D ON without physically lock the gearbox, you again should
see the RPM rise. Repeat doing this you will find the RPM rises each time you try to engage the gear.

All the above are important clues telling that you throttle system is working.

As I know for WIRA(older model) it can still work without throttle body. You can try to unplug the connector to the
throttle body. Your car should start and the engine will not die off.

The engine only dies when the throttle try to work but work wrongly.

Note: Wander why I knew all this??? I am an electronic designer who write MCU programs and fully understand
how the program should behave. Meantime I am in the process of designing a throttle analyser hoping to
relief many foreman ignorance on this item.

Thanks.
Liew

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Added on September 20, 2012, 9:55 amHi,

I am Liew.

'But stepper value is 0 always. After cleaning TB & induction box, my car maintains 900rpm no A/C. 300-400rpm on A/C & no fluctuate, fortunately.'

The symptom above is nothing more than telling you that your car throttle body totally fail to operate.
A good throttle will keep your car rpm constant at (probably 800..900rpm) regardless of aircon On/Off.

However your car should still run but just not performing stable and engine shaking only.

Try to get a throttle fix up but make sure the shop give you warranty (i.e 3 to 6 months) otherwise just live with it.
Thanks.
Regards.
Liew

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Added on September 20, 2012, 10:09 amDon't drill hole, it is not the right approach.

The car throttle work to save for fuel at all condition and not only for aircon. Most foreman told u it is just for 'aircon' but in actual fact it is for everyting.

Among them are
1: When you engage gear, the engine rpm increase to prepare you with more power.
2: When you turn ON the headlamp, the rpm also increase.
3: More saving, when you car comes to a complete stop, your rpm reduces further. It is great saving in traffic jam
condition.

Using traditionally air suction valve to regulate for air con is 30 to 40 years technology and it is rather unstable
Thanks.
Liew

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Added on September 20, 2012, 10:16 amSome car can work without this servo motor but some cannot live without it. For newer car it is a must.

Thanks.
Liew

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Added on September 20, 2012, 10:20 amI sound like you get a mechanic who knows nothing about electronic. He is just take you for a ride.
All this need knowledge and experience and not simply swap with compatible.

The engine ECU and throttle has to match, otherwise it will not perform as expected.
Regards,
Liew

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Added on September 20, 2012, 10:31 amTake note that the throttle mechanism without the motor or gear working , can also ramp up and down.


This can happen if your idling setting is too high and can be nothing to do with the electronics.

Thanks.

This post has been edited by Walter Liew: Sep 20 2012, 10:31 AM

Sometimes faulty main fan motor causes erratic idle. Try disconnect main fan motor and see if idle return to normal. If so, you know what to do.

Hi gang,
I’m experiencing the same as mentioned on another thread.
Rough idle, almost stall on startup, stalling on deceleration. If I touch the accelerator when started, erratic idle- high revs. Seems to drive normally despite the idle trouble.

I have replaced the following:

Valve adjustment
OEM map sensor
PCV valve
OEM Surge tank sensor
Air & fuel filters
Temp sensor (big one on thermostat housing)
OEM O2 sensor
NGK plugs

Good fuel flow & 40psi
Crank sensor checked, (even though engine starts)
Throttle body cleaned.
Injectors checked.

No change in symptoms as yet.
Usual vibration when thermostat fan or a/c runs with no effect on idle.

Awaiting new OEM throttle body and OEM VDO spark plug leads, hoping the new throttle body rectifies the issue, update when fitted.

I will try this while I wait for new throttle body 👍🏼

No change when disconnected

Wow..why do you change all these things without first finding out the issue? How much did it cost for those parts and workmanship? Over 1k? BTW, what car?

Have you checked the ignition coil and the cable? IACV?

2005 VDO Jumbuck, process of illumination.
The map sensor had a broken nipple, so replaced.
The mechanic did the valves, to improve manifold pressure from 13 to 15, and coolant sensor because of cold start idle.

I replaced the pcv, plugs, leads, air/fuel/oil filter when servicing. The surge tank sensor clip was broken so replaced also.

Has had a used throttle body fitted, but a friend said a new one fixed his idle issues.

The mechanics answer was to send ecu, wiring and keys off to be checked, as he exhausted all avenues (swapping parts of his Jumbuck to see if it changed anything) he returned it with no real change. $300AU

The first new throttle body I got was damaged in shipping, so I am waiting for another one.

Update

Have replaced throttle body with a brand new one from proton, and no change to the issue.

Also installed some 8mm NGK leads and a new denso fuel pressure regulator.

It’s truely got me stumped. I might have to try a new mechanic, I’ve found one that does a lot of newer model Mitsubishi mods/servicing, get the coil checked and the intake manifold for vacuum leak. Hopefully they have the diagnostic equipment needed..

Thanks for the update. It is really interesting to see what is the problem and why it is so hard to diagnose. Hope you are able to find out the culprit.

Can anybody explain what this part is?