Rough idling when aircon thermostat is on....

[mark_t]

you might have a malfunctioning idle-up system.
an idle-up increases the idling rpm of the engine when your aircon is on, because aircons eat up significant engine power. if they do not idle up, you would get a rough engine idling. namamatayan pa nga...
but why don't you have this rough idling when the engine is freshly started from cold? because your engine choke is still functioning. it functions like your idle-up, but only when the engine is cold. when the engine gets hot, this choke signs off. and that is when your problem starts..
... i think..
good luck.

oops... diesel pala. at isuzu pa.. ewan ko if if my explanation still holds..
iwan ko na lang dito, at baka may makinabang..

Yes, it still holds. Its idle control valve, local mechanics and stockman call it VCV
or vacuum control valve. Just follow that rubber hose the size of spaghetti for leaks.
Most of the time it just falls off for some reason so you have to put it back on.
Or replace for a new one.

You check it by covering the hose with your finger to feel if it sucks air.
If it sucks air then it works and simply put it back on.

[rdc]

sir, na try nyo n po ba i pa check up ung injection pump nyo? kc palagay ko nan dun ang problema.. pwede pong barado na injector
mag kulang po ng supply ng fuel.

[jvnj]

Thanks sa reply mga bros...na check ko na lahat sinabi nyo...pero sa Injection pump na lang ang hindi....may effect din ba sa injection pump ung pag activate ng aircon thermostat?kasi dati tumataas yung RPM ko, pag nag engage yung thermostat, ngayon hindi na gaano nataas yung gauge, pero yun nga epekto, nanginginig sasakyan na masyado.....

Meron bang timing o activation system sa Injection pump yung pag engage ng clutch sa compressor??...baka po wala sa timing yung injection pump ko ano?...

Dr. D....malapit na yng input mo sa problem ko, pag malamig pa naman makina, smooth pa engine, once maginit na nga yung engine, tapos nag aircon, saka nag start yung engine surge...may choke din ba ang diesel engine?

Ok pa naman siguro compressor ko ano mga bros, kasi malamig pa naman buga ng hangin eh...

Sir dr. d is correct. Based on your lastest comment, your idle up system is defective. Check your hoses going to the idle up mechanism for possible cracks, might be a faulty solenoid, or if still not, either your line is clogged or your diaphram is leaking already. Better have your car checked by a specialist

[yourman_2nd]

i also think the problem is with the idle-up system. it may be the hose or the idle-up mechanism itself.

[acergy09]

yun!!....thanks mga bros sa inputs nyo....baka nga sa idle up system, kasi nga pag nag aircon lang pumapalag at nag vibrate ng husto yung sasakyan eh...kung ang purpose ng VCV ay mag adjust ng idling pag nag ON na yung thermostat ng aircon, walang duda na dun na nga yun, kasi hindi tumataas masyado yung RPM gauge ko pag nag nag swtich on yung thermostat ng aircon, parang kinakapos sya ng fuel, kaya nag vibrate..hayss,sana yun na nga ang problem, nakakahagas pag ganun yung Sportivo ko......maraming maraming salamat mga bros...but any comments are still welcome...

[acergy09]

mga bros...ok na...idle up switch nga, stuck up, pina adjust ko lang, ok na uli...thanks uli mga bros...