RPM

guys help me out i need to fix a problem with my engine idling coz once ive ignited, the rpm goes down upto btn 0-1 which makes the whole car vibrate then at times like in the mornin it just goes off after ignitin so shida iko wapi ive changed the plugs and coils but wapi so shida iko wapi sasa and where can i have it fixed.

Make ,model and YOM.

RPM between 0 and 1000 is very good for idling, should idle at around 700 RPM

If the car is shaking and behaving erratically especially after a cold start, you might want to get your PCV checked

Jaribu kuangalia mass air flow sensor which could be kaput

the rpm drops to kitu 500 when ignited i will try n ask the mecs about the pcv tho i doubt kama wanajua hio ni nini this guys can really mess you up

Try cleaning the throttle and checking that sensor umeambiwa. It may be starting to fail

RPM should be between 0-1 X 1000, about 650-700 for most petrol inline 4 engines at parking or neutral and hot, but if it is 500 then you got a problem. or have it diagnosed and replace the oxygen sensor, most likely upstream (lambda sensor). diagnosis is to get the particular oxygen sensor with the problem.
If not check throttle body. Your problem has to do with airflow especially if exhaust smells of petrol.

Yangu huwaka then starts reving on its own, at some point it vibrates but after a while things quite down, haina tachometer so sijui revs huwa ngapi ikifanya hivyo

OP answer this question. Maybe your throttle body is clogged. Maybe your iacv is messed. Maybe your tps is also messed or needs adjustment.

Start by answering the tagged question.

exactly my problem ukiwasha it raves high then goes down mpaka rpm 500 if i dont kanyaga mafuta kidogo it goes off so far ive spent kitu 15k+ full service coz pia ilianza kukunywa kushinda uncle uwes

The revs go high when you cold start so that vital metrics such as oil pressure and temperature are not below threshold. the the computer brings it down slowly as temperature goes up. but for any car, even without computer, the engine will start with a high rev for a few seconds because of the fuel pile up for the several times the starter turns the engine over without a burn. all that is normal, but 500 revs for inline 4 at parking or neutral means there is a problem.
remember if your car does not have an electronic accelerator but uses a cable the adjustment might be the problem. I had a guy with such a problem and i just adjusted the throttle and cable for him and that was it. Ideally, an automatic car should not have the cable accelerator because the engine cant adjust throttle properly when you foot is on the brake. with manual you can always rev a little before loading the clutch. its a small problem but very common and can be corrected without a mechanic if you are familiar with a car’s internals.

Check plugs kwanza if they need replacing, if they are OK make sure they are fitted correctly.
Check mass air flow sensor most probably kuna soot Ime build up have it cleaned/ replaced

last week i had a mec who removed the throttle and made me buy that cleanin spray which really improved the idling untill today mornin it went back to usual 500rpm then off the engine goes

How do you answer this question without details?

You: Doc, I have a fever and diarrhea.
Doc: Here’s a prescription for a coffin.

@ngomi you have been asked this question several times and you seem to ignore it.
Even if it is a 1st generation Toyota no one is judging you.

:D:D:D:D:D

ok sawa its a toyota yes engine is 1zz YOM is 2003 first owner and besides normal service and suspension it has never broken down so mayb i need to change some stuff.model ntajianika

am tryin upload a pic of the engine nalemewa someone tell me how niweke hapa priss

Osha throttle body then locate the carbon sensor usafishe pia ama ubadilishe.

Wasomi munakuwanga na ujinga sana. Sasa how do you expect an ordinary driver to make out what PCV is? Break it down in a manner that both specialized and non specialized audiences can relate, we were taught.