Check Engine and Idling Problem

[red_888]

Guys need help naman my car is a Avanza 1.3.

Got idling problems which started last month, and then lumalabas ang check engine light nya. I did my research and mostly Idle Speed Control Valve ang sinasabi. Pumunta ako sa Shell Service Station and pinalinis ko yun ISC Valve, after ilang days lumabas ulit CEL and nagkakaproblem na sa idling ulit.

So what i did is bring it to a Toyota Service Center to have it scan. Ang lumalabas nga is yun error sa ISC daw nya, may inayos siya and sabi na mukhand hindi maayos ang pagkakabalik ng throttle body and isc valve. Pero ang recommendation nila is to have the ISC Valve replace. Nawala naman for a moment ang CEL at idling problem pero after a week bumalik na naman ang problem. Observation ko lumalabas yun CEL pag cold start then on/off siya for a while pero nawawala upon driving for a while.

Hope you can help me guys. Kelangan ko na ba talaga palitan yun ISC Valve.

Thanks.

[red_888]

Guys update lang, nagpa scan ulit ako sa ibang toyota branch and it shows na throttle position sensor. Ni reset nawala for a week then bumalik ulit ang CEL one time.

[jick.cejoco]

What was the idling problem?

Erratic idle speed?

Idle speed too low?

Idle speed too high?

[red_888]

as of now pag bagong start minsan tumataas umaabot ng almost 2k then biglang babagsak yun parang mamatay na engine tas biglang babalik sa 1k rpm.

pag matagal na tumatakbo yun auto sir mag normalize na yun idling niya.

[jick.cejoco]

What is the engine type/ family? e.g. 3EE, 2SE

[pakjun]

if the scan gives you the ISC problem then that's the problem. try to clean the ISC valve. there are videos in youtube on how to do it. usually brake cleaner lang ang gamit na panlinis. and while you are already on it, remove and clean the throttle as well as other sensors attached to the throttle with the brake cleaner.

[newtocar]

Nangyari din sa akin ang ganyan sa ford focus, ang naging problema nabaraduhan ung air intake ng makina galing air filter, kasi nilinis ng mekaniko ang air filter at hindi naibalik ng maayos ung pipe connector ng filter housing sa intake. Un ang una kong binuksan at inayos. 10K na ang tinatakbo at wala nang naging problema umpisa nung inayos ko.

[oj88]

There's an Indonesian blog that mentions this problem and describes troubleshooting procedures here (Google Translated to English): https://translate.google.com/transla...-sempurna.html

This ISC valve is very similar to a voice coil or stepper motor (same operational principle to a speaker or a hard disk read/write arm) that allows the ECM to precisely adjust the idle speed. If the coil is shorted or open or has changed its resistance, it may not respond to the ECM's command properly causing it to work erratically. Either that or the problem could be mechanical in nature... ie. the pin/plunger/piston no longer travel in and out smoothly (see diagram below).



I'd put my money replacing the ISC if

1. The measured resistance across the pins are off-spec, or
2. The plunger binds or sticks

[jick.cejoco]

There's an Indonesian blog that mentions this problem and describes troubleshooting procedures here (Google Translated to English): https://translate.google.com/transla...-sempurna.html

This ISC valve is very similar to a voice coil or stepper motor (same operational principle to a speaker or a hard disk read/write arm) that allows the ECM to precisely adjust the idle speed. If the coil is shorted or open or has changed its resistance, it may not respond to the ECM's command properly causing it to work erratically. Either that or the problem could be mechanical in nature... ie. the pin/plunger/piston no longer travel in and out smoothly (see diagram below).



I'd put my money replacing the ISC if

1. The measured resistance across the pins are off-spec, or
2. The plunger binds or sticks

And do the proper relearn procedure

[red_888]

thanks guys

Napalinis ko mga sir yun ISC valve and throttle body nya. Ang lumalabas sa scan is throttle position sensor.

pero pinapabalik ako ulit ng toyota to check again if yun na talaga ang kailangan ireplace. Sana nga hindi naman yun isc kasi medyo madugo price hehe.