Most Toyota cars (Toyota and Lexus cars) are well made quality wise kuloliko gari nyingi zinazo tengenezwa na other automatic makers. Yaan namaniisha ni reliable, durable, dependable--yaan frequency ya breakdown ni minimal with less maintenance, simple design of various parts yet functional and last long time, unlike other brands .(except for Honda)
Niende kwenye mada...ac inavo operate ni kwamba pale compressor inapoanza kufanya kazi basi idle speed(silencer) lazima ipande ili kupokea mzigo wa compressor..kumbuka compressor inahitaji nguvu kiasi ili kuifanya ifanye kazi kwakua ikiwa inafanya kazi pressure upande wa high side inaweza panda mpaka PSI 250+ hasa wakati wa jua kali hivo kama injini ipo silencer inahitajika iongeze kuweza muda mzigo huu wa pressure ya ac.
Sasai inapotokea gari kuzima unapo washa ac yafuatayo yawezekana kua chanzo
1. Silencer itakua ipo chini..sasa hapa either ufanye adjustment ya silencer (ingawa hii hufanywa automatic na gari yenyewe kupitia kitu kina idle control valve so yawezekana kimejaa carbon kinashindwa ku adjust kiwango cha hewa wakati wa low RPM,)
2. Kama umejaza gesi ya wc hivi karibuni basi gari yawezekana wame overcharge refrigerant..(IST system yake inachukua gram 360 kama haujabadirisha compressor yake ya umeme) sasa ukiweka gasi nyingi maana yake inatengeneza pressure kubwa mno kwenye system..na kufanya gari kua nzito au kama ipo silencer inazima gari pale compressor inapowaka, so kama hili ndo chanzo basi gasi ikipungua to manufacturer spec basi gari itatulia-but fund lazima ajue kutumia gauge vizuri na apime pande zote mbili low na high kiweza kuona kama pressure zipo sawa)
3. Kama umebadirisha compressor (yaan umetoa compressor ya umeme (variable displacement compressor) umeka compressor ya external clutch (fixed displacement compressor) au kipumbu kama zinavoitwa tanzania hapo huwa kuna shida kwakua working principles za hizi compressor mbili ni tofauti kidogo.. compression ya clutch ya nje it always operate at fixed displacement, na performance yake inaongeza ukikanya mafuta zaidi..hii compression ina operate at its full capacity all the time regardless of temperature demand na haina adjustment yoyote ya output kama compressor ya umeme, therefore inakua ipo too heavy kwa injini (na ndo maana gari za kileo haziji na hizi compressor clutch nje AKA kipumbu.
Sasa kwakua hizi compressor za fixed displacement (kipumbu) zinakua heavy na ukiweka ambayo ni over size kama compressor ya starlet basi gari lazima itakua ina zima wataki wa low RPM hasa pale compressor inapo bana clutch yake...au gari itakua nzito hata kupanda mlima inaweza shindwa na itakua inakula mafuta mengi sana. Na wengine mafundi hupandisha silencer but bado utasikia vibration ac ikiwa inafanya kazi.. solution hapa ni either irudishwe compressor ya umeme, au uweke compressor ya kipumbu angalau yenye uwezo almost sawa na ile ya umeme ingawa bado gari haitakua sawa kama ikiwa na compressor ya umeme
Kumbuka compressor ya umeme inakua adjusted na computer ya gari (ECM) kuweza ku alter performance (output)ya compressor lakini pia condenser fan na bila kuumiza engine, but ukitoa hii compressor ukaweka modified fixed displacement compressor basi computer inakua haina control na performance ya compressor na computer inakua haipati correct feedback ili kuweza ku adjust engine performance accordingly, hence injini inazimika au vibration zinakua nyingi.
Kingine labda condenser fan yako haifanyi kazi vizuri ili kuondoa joto la condenser pindi ac inapokua on, sasa at low speed unategemea feni kuweza kupoza condenser sasa condenser isipo poza vizur gasi ya ac pressure kwenye system hujaa(expansion hutokea) na kufanYa injini ielemewe na pressure ya compressor, hapa gari inaweza zima pia. So check kama feni yako inawaka na ipo kwenye muelekeo sahihi unapowasha ac.
Au pia blockage kwenye condenser passages
Au pia compressor is about to seize..
Kingine ambacho ni kikubwa zaidi ni engine kua na low compression for whatever reason nayo inaweza changia injini kuzima wakati wa low RPM pindi inapo bebeshwa mzigo wa ac..japo hii kitu ya mwisho kutazamwa kam vyote hapo juu vipo sawa.
Ku address hii changamoto unahitaji Technician anaejua how car ac system works ili kujua where to start kufanya diagnosis. Ni simple kufanya diagnosis na kutatua tatizo kama you only know series of mechanisms zinakua involved mpaka AC inafanya kazi kwa namna inavotakiwa.
