Help! Car stalled suddenly.....

[speedoSTAR2099]

To all sifus out there.....I need help urgently......Thanks in advance for all ur feedbacks....

Currently i'm driving a Wira with 4G61T manual transmission.....

The problem i'm facing is that.....My car's idling is smooth at times....idling around 1100 on idle with the a/c on....but after running the engine for awhile then as i am slowing down....the car's rpm would drop till about 300rpm n then will rise back again until 1500rpm then the engine would suddenly stall....this incident doesn't happen when the engine is cold or running on short distances.....and also not all the time when i'm trying to slow down....it syok syok happens....and when this happens, on the attempt of slowing down before the engine stalls, the rpm will be a bit sluggish.....

I've been trying to troubleshoot this problem for quite some time already but still couldn't manage to pin-point the fault.....I've cleaned the trottlebody, replace the engine temperature sensor, replace a brand new K&N air filter and also checking the fuel line....

I've got some parts that i've suspected for the fault, but not very sure whether those parts does control the idling part of the car....the parts are rpm sensor, oxygen(O2) sensor or the Idling Speed Controller(ISC).....

This problem occured the day after i've changed the timing belt and also a new radiator....

I hope all you sifus out there would offer me some expert advice on solving this problem....it's getting me frustrated already....Thanks again.....

 

[tk2005takeru]

I dunno if this works for u...

Does the new radiator got 2 fans?? If so the other fan will suck up a bit of juice from the battery to blow off the hot air if it thinks hot... That will cause unstable RPM idling rev... It will drop the idling rev a bit but after it shuts down, the engine will return to normal... I think putting a voltage regulator will help here, or try those grounding...

This happens to my car so I've rev it up a bit to suit the lowest RPM condition... Lowest RPM can be obtain(if u dun hav voltage regulator or grounding) by:
-Switch on A/C
-Switch on Lights
-Turn the Steering Wheel to the max so that the power steering will pump the oil harder, thus resulting more lower RPM rev.
-Switch on Back windshield heater
-Switch on everything that u feel will lower the RPM a bit...
Then rev it up to suit the lowest RPM condition. But I dunno when doing it damage the car or not, but I know the fuel consumption will jack up higher a bit...

 

[Doink]

culprit ISC!!!...

 

[sakuraguy]

Speedostar: Is the guy fixes timing belt for u made correctly? .. Timing belts are very important and accuracy needed in doing that or it could damage ure engine as well. Please refer back to the workshop u have done for a re-do or warranty purpose..

 

[speedoSTAR2099]

Thanks for the feedbacks ya bros......

tk2005takeru - yes, my radiator indeed has two large fans....the mechanic did told me before too that once the temperature get hot, both the fan will spool, therefore dropping the rpm....but one thing I doubt this problem because before I change the timing belt, and radiator while using back my current fans, I don't face this kinda problem....the idling was so stable then....the only engine stalling problem I had before happened only if i was travelling on high speed then on a sudden i hit the clutch with the brake too hard....but now it seemed that even on idle, the rpm would go crazy and just drop dead....

Doink- the ISC is also one of my major suspected fault but my mechanic checked it and told me that my ISC is in working condition....but what i felt is that maybe, just maybe, then when the engine runs for quite a while, the ISC turned weaker and weaker, then all of a sudden, it becomes faulty....but i'm not sure whether this is logical anot....hahahaha

sakuraguy - I once read a post out here on zth about faulty timing belt position....i mean that the timing belt is placed not accurately....then i also had approached my mechanic, i left the car at their workshop to ask for checkup, in the end they told me that it was placed correctly, but what i'm not so sure is that whether did they really took the whole timing belt out n place it correctly back again....cause for the process of taking out the timing belt would take quite some time and lots of work....not darn sure whether they really checked for me.....

but then how about the O2 sensors? what do they actually do? can this idling problem be related to them?

Thanks again for all ur advice....I really appreciate them.....

 

[tk2005takeru]

O2 sensors could also be one... Try to check everything around the timing belt and the radiator, see if anything is unplugged or forgotted to screw back... Sometimes even 1 thing unplugged can cause tons of other stuff...

 

[jigc]

i dun think it O2 sensor.
even u r running a faulty O2 sensor, it will not die ur engine, the ecu will detect error in value and run the engine rich with its preset value.
how about throttle position sensor?
if ur car only dies or rpm not statble with ur fuel throttle off, it is to do with TPS.

 

[putra4767]

o2

Yup, it may not be the o2 sensors

 

[chinozie]

service ur throttle body...

 

[zan]

i faced similar problem with my 4G92 last few weeks. found the ISC plastic gears broken inside so changed it. but idle speed becomes worse even. then i sent my wira to EON for a diagnose.

it turned out the ISC servo had melted. solution = change complete throttle body.

cost new = RM1300.
used = RM350.

but i havent change yet...just celebrate raya..pokaii.. :D

speedostar, u might check complete throttle body. maybe same prob with my 9 year C98 wira.

it may happen also if air flow meter (air mass sensor) not plugged in properly.

if still not happy, sell ur 4G61 to me...he he he i will convert to carburettor :lol:

 

[speedoSTAR2099]

jigc - well, the TPS i had changed already, and that solves my other problem like car jerking on full trottle....but it doesn't help on maintaining my idling problem....

chinozie - the trottle body had also been serviced....but still no luck....

zan - erm....where does the air mass sensor located? and what does this air mass sensor actually does? The problem is that my mech told me that my current ISC is still in working condition....but if it really are the one in fault, well, i could get another ISC, and no need to buy the whole trottle body it self....can save a bit ma....hahahaha.....

aih....i really hope i could find the culprit of this fault....even got cash in hand and wanna solve it also kenot cause couldn't find the error....pls give in more advices or any other part of the car that you all feel related to this kinda problem.....

thanks y'all

 

[jigc]

pls make sure adjustment of tps is right:

http://s3.invisionfree.com/WiseAutoClub/index.php?showtopic=1524

i'm not sure how ur mech adjust the fixed SAS

 

[bullet_7037]

yeaa...my 5 ys old wira got a same problem too....my frenz advised to chance a fuel pump...not yet done tgh kopak beb.. but not that serious....alwaz died under hot sun driving. mayB u can try n let me knw the result

 

[chinozie]

check ur AFM...happened to me before...
changed to a better one...all seems to be ok...

borrow one from ur fren...n see how...

will this help???

http://www.dsmtalk.com/forums/archive/index.php/t-63707.html

 

[zan]

air flow meter or air mass sensor functions to measure the volume and speed of air inside air filter box. the input then send to ECU then only ECU will calculate how much to spray fuel, or how fast. the combustion mixtures will be measured again by oxygen sensor (lambda sensor) at the exhaust pipe. if too much unburn petrol, then ECU will calculate again the sufficient fuel to be sprayed.

the location..of coz laa at the air filter box. if not mistaken, its plugged in at the flexible hose between air filter box to throttle body.

remove and refit plug and ensure its plugged in properly.it also can happened due to false warning.. which can be erased using electronic diagnostic tools or by removing battery terminals overnite. the tool i mentioned avialable at EON know as MUT. can check 4G63, 4G92, 4G93. later version is called PDT. can check almost all proton/mitsu engines including SP4H gen2, 6A12 V6 and 4G13/15 step 2. false warning can also cause problems...ECU thinking sumthing wrong but dunno whether is or was.

 

[speedoSTAR2099]

jigc - About the TPS, on the day when i had it changed when i was hoping it could solve the idling problem, the mech did try it a few rounds, checking on the reading with the ohmmeter and readjusting the TPS position and it still doesn't do any good....but i'm not sure whether the mech is doing it right anot or does he place the TPS in the correct position....well, i'm not a DIY kaki, so i daren't do any fancy stuff to the car alone....later i might screw it up even more....hahaha....i'll try to ask my mech to check on the TPS again on my coming visit to him....by the way, thanks for the DIY link u attached....at least it does gimme some idea on how to check on the TPS....cheers buddy!~

bullet 7037 - as for the fuel pump, i don't quite think is the culprit to my idling issue....but what the heck....might as well ask my mech to check for it too....hahaha....and my car's idling also goes haywire only when travelling long distances, it wouldn't happen if i was travelling on a short distance no matter if fast or slow....therefore, i suspected something related to temperature issues cause as i travel on long distances, the temperature would rise, then the 'thing' would create problem then....not so sure tho.....just my 2 cents....

chinozie - sorry ye bro, what's an AFM and what does it do? Thanks for the article, i've read thru it, it gave me some extra pointers....

zan - oh ya, now i know what's the air mass sensor is....cause i used to call it air flow sensor, then i thought it's a different thing then....hahaha....the air mass sensor is also in my highly suspected culprit list along with the O2 sensor....hahahaha....so, if the O2 sensor detects a lean reading on the air/fuel mixture, would it make my car 'mati engin' on idle? Due to the O2 sensor located at the exhaust system, therefore i am suspecting it as the main problem....cause like i've said before, the problem only exist on long distance travel....maybe the O2 sensor already 'half-dead', working at times and also taking a break at times...hahaha.....I've once taken the car to another mech which my friend is quite fimiliar with and the mech plug in a diagnostic reader to my ECU, and it displays two error codes, one for the TPS and another for the O2 sensor, therefore i've changed the TPS, and the mech unplug/off one of my two O2 sensor....so now currently, i'm not sure whether he unplug/off the faulty one or the working one....

 

[chinozie]

AFM - air flow meter...(dunno ur model called it what)
from throttle body...then goes to air intake (air hose)...then the thing that look like a box...just right before your air filter...