hi all

my car have this strange problem that started few days ago.. hope someone here with experience can teach me... is there any problem..

each morning when i start the engine
the engine will 'vibrate' a lot, with 'rythm'
how to describe..
feels like a lot of vibration...
like we pull out one or 2 plug cable (When the engine runs on 2 or 3 cylinder)
that kind of huge vibration

then after a minute or so,
only the auto-choke start functioning,
and after the choke functioning, every things seems smooth
and after the engine is warm enough, everything is smooth also


so what could have cause this problem?
anyone here can help me??

information..
- my engine is A15, with hitachi 306 carb with auto-choke.
- last change of spark plug is around 3000km before.
- i live in tropic... where temperature here is not cold at all.. lately is raining season so temperature might drop 2 or 3 C
- i use my car on short distance everyday.

anyone can help me??

thanks..

mate is it just wen its idling or does it do it at a few thou revs?

hi...
yes... it 'shakes' when at idle and also at rev...
even i rev it high also it will shakes (with 'rythm')
vacuum gauge needle is shaking also, between 16.5 and 18...
really vibrate a lot...
so for the first few minute or so.. it is.. almost impossible to drive.. the car like not moving, the engine shaking.. then if i press the accelerator sometimes the car suddently accelrate ...

but everything went back normal when the choke start functioning..

check air:fuel ratios.
if it stops wen choke comes on, it mite b runnin to lean at idle

oooh.....
later i play with the mixture screw and sees how it goes...

might be my previous mech....
cause the engine comes from japan where the temperature is cold and the choke disable slow... then the mech migh tune my engine when the choke is still on...


i also thinking spark plug problem..
(cause the vibrating seems like.. 1 or 2 cylinder not working)..
could it be spark plug problem?
cause the problem dissapear after the engine is warm... ?

if its runing on 2 or 3 cylinders, itll make a different noise, not necceserily shake

try playing with the mixtures

i have a similar problem with the coupe but with the manual choke, when the choke is engaged you wil lhave this problem, its more like the engine is stummbling as the air fuel mixtures are wrong, if i use only 1/4 of the manual choke it will stop this and be fine... and idle smoothly.

With the auto chokes on the a15, i think you will find the old temp sensor spring or coil, whichever you want to call it wont be within its opperational lifespan any more and not work consistantly in the same manner (happened to mine) just disable the auto choke or move to a manual choke, they are easier.

sounds like the choke is not operating correctly. choking the engine tooo much.If you look at your tail pipewhen this is going on it might have black smoke coming from it. That means the mixture is too rich.

ooh..
so i ask someone to step on the accelerator to rev.. then i can see black smoke comes out ? or is it black smoke when idle..? i really should check that out...
(kinda embarassed if ppl see my car on street with many smoke.. :D )

Black smoke at idle is the choke , which should stop when the choke pulls off. Black smoke all the time means that the mixture is wrong. jetting may help