Fluctuating idle RPM (on Petrol)

[imtishal]

I have noticed a fluctuating idle RPM problem.The continously needle moves up and down between 900 and 200.
2ndly,when i rev up the car it doesn't accelerate smoothly but makes jerks.lagta hai jeyessay petrol khatum ho gaya hai ya phir koi plug kaam nahi kar raha.or car 120km/h say oper nahi ja rahi.
i have checked the plugs and they r fine.
how to check the fuel flow/pressure??or check if the fuel pump is working fine or not??wat other reason could be for this problem??Car is honda city 2002 exis,cng installed

[shrm1]

You might have some trouble with the throttle body.
Get the butterfly checked. Just my opinion...let the experts guide you better

[hash4u]

u told us everything but which car

[irfan5]

not a big issue if solve properly... your throttle body needs a service just go to honda dealer and get the work done.... then its done.....simple......
can you tell me when did you tuned your car on cng last time........

[aantherax]

No worries Imtishal just get your throttle body washed i used to have same problem after driven my city 84000Km the guy charged me 1500Rs and its good now ever better then b4

[c123pk]

Rs. 1500 for washing throttle body ?? you can wash it by buying the spray yourself for Rs. 100

Rs. 1500 ????

[JUE]

Asalaamu alaikum

Bhai...NASA ka Carb Cleaner leylo..cost Rs. 220/- turn your can on petrol spray as per instruction written on it on Throatal body ventury after removing air cleaner..and feel the difference rpm set..soft accelarator..pic etc..

[graybmws]

Could be an engine trait.

Both my BMWs have double vanos engine management, which due to variable timing of valves, slightly fluctuates the RPM at idle.

[imtishal]

Thnx guys for the reply.
I have got the throttle body serviced 3 months ago.AND again i washed her with carb-cleaner a month ago.So i think it shouldn't create problem so soon.Anyways,will try it again as suggested by JUE and c123pk.

@hash

Yaar i have already meintioned it's honda city 2002.

@irfan5

I got CNG tunned 2 months ago.But was not satisfied with the result so i twicked it myself.And No it's not because of CNG tunning coz it's totally seperate setup(i mean different screws)

@all

Could this be due to malfucntion of IACS??(idle air control sensor).2ndly,Where in ISB i can get the car computer codes scanned??does only honda have this facility or else?

[papubhai]

timing belt issue get it checked immediatly

[imtishal]

@papubhai jaan

timming belt has been changed at 85K and now the odo reading is 110k

[hash4u]

lol @ timing belt
@imti
a colleague had the same problem. its a matter of adjustment. did anyone try fiddling with the tps?

all honda pit stops have the software for OBD.

[aantherax]

C123pk i could do that by just removing the air filter box but the guy who charged me 1500 completely took the thorottle body outta the hud washed it infront of me and i was like shocked to see the dirt type thing coming out of it... and he then adjusted tepits and tune up of CNG as well

[whisky]

Get your Intake air control valve IACV i believe cleaned.

[ahmadbila]

just get throttle body cleaning nd tappet adjustment frm honda ppl nd then cng tuning.ur car wud b fine...nasa carb cleaner is just all rubbish...makes no difference..believe me.

[ce096]

hello my friend yar i own a civic 95 carburator
i also hav the same problem i hav seen 100 mechanics spent almost 2000rs on it but its still droping down yar bcoz of it even my booster doesnt sound good
plz let me know how can i stable my rpm both on petrol and cng
damn thing stays at 800rpm then drops to 200 then again goes to 800 then drops to 100 etc
i hav 4 point bosh plugs

[janleva]

i had the smae problem it came out to be a bent CNG pipe taht was causing all the idling and up and downn problems of rpm even on petrol.

[imtishal]

@hash

Tps??if u r referring to tappets then yes they were adjusted when i got the CNG kit services 3 months ago.
Thanx for the software info.

@aantherax

Bro removing the throttle body of honda city is surprisingly quite easy.just 4 bolts and few hoses nothing more.

@janleva.

Please explain,As i'm unable to understand that how a bent CNG pipe has anything to do with unstable RPM on PETROL.

@All

yesterday i have tried cleaning the throttle body as suggested by alot of ppl here.And the problem seemed to have subsided after that.Also cleaned the plugs.Now lets see how long will this work..
Thanx All for all the help.

[Xplorer]

Also clean IAC (Idle Air Control) valve with the same carb cleaner. It can not be opened up, just remove it and spray a lot of cleaner in it.
Best of luck with your ride and the experiments you are doing with it!!! Its always good to do such minor things yourself after discussing at PW.

[imtishal]

@xplorer

I have cleaned the IAC.Donno about others but in city it's removable from throttle body.felt car became lighter and responsive on CNG.Thought about doing the DIY But didn't had my mobile with me at that time.Anyways,the problem has arose back again.So I need suggestions and possible solution.wake up guys.....