Engine Vibrates alot AfteR changing Pistons and flywheel

[escksu]

I did a minor mod to my engine. Change pistons from 1.6 to 1.3 one as well as a lighten flywheel. I also change gearbox mounting and new crank sensor.

However, the engine now vibrates alot on idle and its quite horrible as RPM goes up till around 3K. After 3K seems to smooth out.....

Any idea what is wrong with the engine??

 

[neohadri]

Maybe because of high compression? or ur new mounting?

 

[crazykatak]

u did engine balancing when u decided to lighten flywheel?
changing pistons alone won't give such issues unless assembly was not done correctly or "finishing" is not done nicely ( example: sensor sockets not plugged in, installed timing belt incorrectly, missing or skipping 1 teeth at the cam gear, etc. )

what i could suggest you to do is to re-check the engine timing; not idle speed or spark ignition timing..but the at the cam gear markings and at the timing sprocket markings behind the crank pulley.
if you're lucky; the cams are sitting at retard position. less likelihood of the pistons hitting all the valves.

have a look 1st.. :)

 

[VDread]

I might be wrong -- but shouldnt the ECU (assuming that you're still using stock ECU) be affected by the change of piston from 1.6 to 1.3?

 

[^pomen_GTR^]

more likely it was due to crank sensor adjustment/location/gap not adjusted properly???



*why change the sensor in the first place??

 

[crazykatak]

crank sensor-dess..

has the sensor same part number ?
i believe that most Satria neo uses PW810614 crank sensor.
however, if using different part number sensor, engine could not start at all..

crank sensor position :
if too near to trigger wheel, it will cause audible screeching noise and all is fine... UNTIL...
engine starts to misfire, misfire, violent misfire, RPM goes to 8000RPM, engine stalls..

try to avoid over tightening the crank sensor ( Allen-key ) to the oil sump ( to prevent premature wear to the magnetic pickup surface ), relocate the wiring away from the exhaust pipe and CV joint ( to prevent premature damage ).


**quicktip: avoid using "local" oil sump..crank sensor seating position is deeper than genuine oil sump..causing damage to the sensor.