Why does the rpm go down from 900 to 600 when radiator fan comes on or when headlights are turned on?
It dose'nt and should'nt happen.
welcome to the guzara on cng club
aamir_aijaz
The alternator gets loaded causing greater resistance to turning.
@hash
Sir! I see that you are an honorary anti-CNG club member
dont know what car yr talking about, but generally there is sensor to rev up engine
this sensor isnt there or disconnected in yr car's engine.
go to a electrician and have wiring chked.
IF on cng it happens and on petrol it doesnot. then check setting only
RPM shud drop on turning on electric load but drop of RPM from 900 to 600 isnt normal behavoiur.Which car u r facing the issue
very common thing in honda's on CNG
Its a mehran but problem is on both cng and petrol.
@Amir Ijaz
If the subject car is mehran then how do u sure about the exact value of RPM i mean mean 600 or 900 etc?
bro .. in mehran how do you noe that rpm decreases from 600 to 900..there is no rpm meter in mehran for sure..
haan haan mesho ki mehran main bhi nahee hai rpm meter..
Aik cheez hoti ha digital rpm meter. China ki hoti ha. 400 ki milti ha montgomery road say. uss mein say aik taar nikalti ha or dash board kay neechay chai jati ha. ye cheez batati ha rpm. ha na kamal ki cheez. sach ke raha hoon yaqeen karo.
wo taar ja ker lagti kahan hay? plug kay sath?
The technical reason is already described by Sami_vadoo.
As far as RPM value is concern it reduces wid load but diffrence of 300 RPM is might be due to inacuracy of tacho meter other wise this behavoiur is normal & even u can observe slight drop it in bigger engine as well even running on Petrol or Diesel.
Thanx every1 for the help. I'll get a new rpm meter and also get the alternator checked.
Thanx again everybody.