I have read a lot of topic on this issues but there were virtually no information on how to cure this problem; ERRATIC IDLING on Proton fuel injection cars.

I own a Wira 1.6XLI Auto and Waja 1.6 Auto.

The Wira have been giving me problems since 2004 when the original Throttle Body fails.
So I have the servo kit changed (2 times in fact); but no good at all.
Proton sell the Throttle Body unit for RM 1200+, so I get a re-cond unit at RM580; but still no good.
Same result as changing the servo kit.

I am an ex-mechanic myself, so I went on a learning spree about fuel injection cars.

Tried reset ECU by taking off battery for 30 minutes, went to workshop for diagnostic reset error code and troubleshoot; every thing is fine; but idling still erratic, especially when air-con kicks in or turning the steering while parking or making a turn.

I've eventually solved the problem... literally!

Here is what you need;

1) flat or Phillips screw driver
2) or no. 8 spanner
3) digital volt meter (must be digital)

Firstly, check the followings;

1) timing set to 12° BTDC (variable range is 8° - 18°) you can set to proper value after adjustment depending on the fuel U use
2) make sure TB Servo is working properly (hot start engine should rev above 1000RPM then drop below that after a couple of seconds)

MUST;
a) set to proper timing of 12° BTDC if not done
b) if TB Servo not working, have it changed

Without meeting a) & b) requirements, this adjustment procedure won't work.

After that, here is the easy part;

1) Start your engine or turn car key to ON position
- measure TPS (Throttle Position Sensor) the 2 green terminals
- variable range must be between 0.5 - 0.95 volts, U try which value is suitable for your car, mind is 0.5 - 0.6 (nice & stable)
2) Turn OFF engine, make sure car key is in OFF position
- turn the air bleed screw all the way clockwise until it locks, not tight - just lock
3) Start the engine & let it run for a minute or so
- engine should open the idle servo to compensate for the lack of air
- engine should automatically rev to >1000RPM then steadily drop to 600/700RPM
4) Engine still running after 1 minute (take your time, let the engine figure out what to do)
- turn air bleed screw 1 full turn anti-clockwise
- engine should again rev >1000RPM then drop to 700RPM or so
5) Let it run a minute or so again
- now ON air-con
- engine should react immediately to the extra load
- ON & OFF air-con a couple of times between intervals of 30 second or so
6) You may turn the air bleed anti-clockwise more, if air-con idle too low
- range is usually 1 - 2.5 turns anti-clockwise

* You are done

My Wira now accelerates better, more immediate and less smoke due to rich idle, engine runs cooler too.
Previously it chokes & accelerate like a diesel vehicle, vibrates during idle; now no more that.

You guys enjoy. Proton car is such a fuzz.

Hi,my Waja 1.6 4G18 is also giving me this erratic idling problem.Like what you said,everytime I switch on the air-cond the idling needle will go up and then drop and this also happens when I turn the steering wheel when not moving.

Does your guide applies to my Waja.Mine is a manual.I am not very good in car repair so hopefully you could provide pictures where the adjustment screw will be in order for me to set it up my own.By the way,would there be any effect if I screw up with the setting.Thanks bro

This post has been edited by 779364: Jun 26 2008, 02:14 PM

is this apply to all proton cars? i dun know how u mention the situation but i do feel my car vibrates when idling...

im driving persona btw

Yes, better to provide picture..cause some of us are noob in engine tuning...including me...hehe..

can use in all proton car? im using gen-2 btw.

i think thats for mmc batch... campro and siemens is different

Will try to post the photo ASA I can.
- The TPS is usually wire black box & attached to the Throttle Body (TB) with 2 small bolt (usually size 8mm).
- There's only 1 screw in a hole on the TB, its the air bleed.

Yes, this applies to all Proton fuel injection vehicles & this concerns idling only, ermmm... I don't know about Siemens TPS.
- Just measure the voltage, if its between 0.5 - 0.95, you're good.
- Follow from step 2 onwards, its pretty much thats it.

Yup when i was driving my wira mmc that time i always play with the idling screw...as low as possible,save fuel ma. Now driving campro car idling set at 1k rpm so suck.

Proton engines do vibrate a little, especially when the air-con + automatic gear engages, otherwise its fine. MYvi do not vibrate at all due to high RPM @ 1000 - 1100.

You only need to remember 1 thing, TPS voltage range 0.5 - 0.95, do not touch the TPS if you aren't sure about this.

You can screw up the air bleed, no problem; the effect is too high, too low or erratic idling, thats all.

For proper idling adjustment, just follow step 2 onwards.

wow... totally noob here
but as long as i know fuel injection engine idling position is cannot be set 1
caburator can because the manual stated there FI car is non-adjustable

Campro different already lo. My blm i on off air con the idling stays at 1k rpm you dont feel any sudden fluctuation in rpm at all.

Here you go.




Attached thumbnail(s)

my car not at 1k if idle, i think around 900 rpm, izzit normal?

When engine idle, RPM meter cannot be too high or too low
Too high = makan minyak
Too low = engine will vibrate

ok so mine is around 900 rpm, n my car vibrate.. so how much rpm u think will make the vibrate stop

The pic is a little small and I can;'t really see the air bleed screw properly.Is there a bigger pic focused on the air bleed screw.Sorry TS hehe

This post has been edited by 779364: Jun 29 2008, 12:39 AM

my nissan car also the same. on air cond idling sure up. turn wheel when not moving also up.

nice information BRO!!

And what if the TPS voltage range is not within 0.5 - 0.95? Any way to correct it?

I just open up the bonnet and I saw the throttle body sensor with the wires coming out of it.But I can;t see the air bleed screw.