car stalls during traffic

[Cleeow]

good day everyone!

I'm a newbie girl driver and is just starting to learn things about a car.
I'm driving 04 Chevy Optra 1.6 A/T. I bought it (2nd hand) last Nov. 2010. On December, I did 100T km check and changed a lot of parts already (through casa in Pasig) such as:

* Oil filter * Inner & Outer Drive Shaft Boot * High Tension wire set
* Air filter * Idler Roller * TIMING BELT
* Fuel filter * Drive Shaft Clamp * Tensioner
* Spark Plugs * Thermostat Assy * Water pump
* Auto tensioner * Fan belt

Then I started having problems around March. The car stalls during traffic and I can't even put it in idle even for a couple o' minutes. I feel the engine losing power (parang naghihingalo) then after few steps on gas & break even on light traffic, maglalaro na pababa ung RPM until the car shuts down. Good thing though, after I give it a rest, the engine will start again. Pero 'pag sa expressway, and continuous ang drive, never syang namamatay! Basta lang pag puro gas and above 1,000 ung RPM,walang problema! (Eh, what the hck, we live in a country of narrow streets and where heavy traffic is just a normal everyday view in the city!) How could that be?!

I brought it back to casa in Pasig & they cleaned the throttle body. Problem was never rectified! Then to another freelance car mechanic and replaced some parts and wires again, still the same! I decided to bring it to Chevy Makati, diagnosis: pull down fuel tank, clean & replace gasoline, replace: fuel pump, oxygen sensor & throttle body. Doing so will cost me a whopping P41,000! (Hindi ko po binibili ung buong repair shop nila!). haha!

Then our beloved Banawe! have scouted 3 big car shops & still, problem can't be found! Although they have advised that changing the fuel pump & the gasoline replacement is not necessary. Mapapagastos lang daw ako kasi pag un daw ang problema, dapat pag namatayan ako ng makina, totally hindi na talaga mag-start ulit! Sa whole throttle body naman, mahina ang P10,000 for replacement!

I am so desperate now and find it so impossible na hindi nila makita/malaman kung ano ang dapat linisin or palitan to solve the problem of my stalling engine! I just don't know kung saang repair shop ko pa po dadalhin tong car ko!

Help naman po please?! I know someone out there will be my angel to help me with this....

THANK YOU SO MUCH IN ADVANCE!

[desert fox]

Welcome sa site sis...

[desert fox]

sis, de computer na mga sasakyan ngayon, dapat compter test ang gawin at doon makikita kung anong me sira...usually me sensor lang na di gumagana jan...

wait ka lang at maraming me mabubuting kalooban magpapayo sa iyo dito kung saaan the best dalhin yang auto mo...

bakit kasi ngayon ka lang nagawi dito?

[spitshine]

hi there po, im 25 from iloilo, sa opinion ko lang po baka po fuel pump po sya. base po kasi sa sinabi mo namamatay pag nag idle lang or pag nag break ka.my theory would be mahina na po fuel pump mo, kasi pag naka straight ka na na byahe d naman namamatay which the suction ng makina sa fuel is grabe. and namamatay lang sya pag stop mo kasi mahina yung higop ng engine sa fuel. im not the best when it comes to cars pero iv'e had this kind of trouble sa 2nd hand car na binili namin dati. hope this helps

[Cleeow]

sis, de computer na mga sasakyan ngayon, dapat compter test ang gawin at doon makikita kung anong me sira...usually me sensor lang na di gumagana jan...

wait ka lang at maraming me mabubuting kalooban magpapayo sa iyo dito kung saaan the best dalhin yang auto mo...

bakit kasi ngayon ka lang nagawi dito?

Nagpa-reset na rin po ako ng comp box, at nagpa diagnose na ko sa 2 Chevy shops para nga po i-comp test. Kahit nga ho gumastos na ako ng malaki kaso hindi naman nila naaayos. Yung isa po sa Banawe inadjust and clean ung "serbo". (pardon for the term,don't know exactly ung right technical word for it po). After nun nag-okay sya for a while then it went back to its same state.

Thanks po for the welcome, been lookin' around this site already, lately lang po nkapagregister! ingat po sir! salamat ulit!

[Cleeow]

hi there po, im 25 from iloilo, sa opinion ko lang po baka po fuel pump po sya. base po kasi sa sinabi mo namamatay pag nag idle lang or pag nag break ka.my theory would be mahina na po fuel pump mo, kasi pag naka straight ka na na byahe d naman namamatay which the suction ng makina sa fuel is grabe. and namamatay lang sya pag stop mo kasi mahina yung higop ng engine sa fuel. im not the best when it comes to cars pero iv'e had this kind of trouble sa 2nd hand car na binili namin dati. hope this helps

I will try your suggestion, kasi I only took the advise of 2 mechanics na hindi daw fuel pump, ipa-check ko na rin. thanks much po!

[bananatype]

Just a guess:
You need 1) air, 2) fuel, and a 3) spark in the cylinders to keep the engine running.

Air -- Lack of air is easy to diagnose, just look at airfilter and check for blockages. Make sure servo of variable intake system is working properly. But this type of simple blockage affects high RPM more than low RPM and idle.

Spark -- Judging from what you said that the engine is fine at high RPM, sounds like the ignition system is fine. If it something's busted then, it malfunctions whether low or high RPM.

Fuel -- A clogged fuel filter, fuel line blockage, or faulty fuel pump can cause the conditions described. High fuel flow at high RPM can overcome a partial blockage, but when the fuel pressure is low a partial blockage can stop the flow of fuel completely. So maybe fuel system has to be checked.

Cheers

[lancy09]

Try mo pa-check/clean yung MAF sensor at distributor rotor assembly.
Nalinis naman ang servo, napalitan fuel filter, bago spark plug, bago high tension wire. Based on my experience, very rare nasisira ang fuel pump. Mauuna pa ata ang engine overhaul bago ka magpalit fuel pump.

[dondonposadas]

grabe naman ang chevy casa di nila ma-diagnose ang problem. sana masolusyonan na oto mo TS.

[bananatype]

Yup could be a faulty MAF sensor. It could be giving wrong signal to ECU to lean-out the fuel mix during low airflow such as at low RPM or idle, hence the stalling in those situations.

Sometimes cleaning it temporarily fixes the malfunction, but if the problem manifests again after the 2nd cleaning then you've gotta replace the MAF sensor (ouch!).

Good luck!