Misfiring?

[tuned]

ride: perdana v6 twin turbo

scenario: after a minor upboost, on max throttle, max boost at 4500 rpm misfiring happens ...can hear crackle noises at the downpipe.... but it only happens at the rpm point not before nor after... nor when accelerating gradually...

solutions tried: plug cables, fuel pump changed, plugs (also the gap) and ignition coil checked....

still the problem persists...

any suggestions / solutions? :confused_smile:

 

[tuned]

~ any suggestions / solutions? ~

 

[m1adam]

maybe ur ignition coil got prob try replace it and check ur ECU pin connector whether its mated properly and do also take a blower and blow the ecu connector sometimes lotsa dust cause bad continuity making certain devices in the engine not to function properly.

 

[cypress8]

Running lean? Check the tip of the spark plug, see whether it turns white. Just my 2 cent.

 

[tuned]

plugs have been checked, same goes with the ignition coil....
everything's fine...

ECU pin?....u mean the connectors at the ECU? erm those should be alrite too...

dun think i'm running lean....as i'm already running on an aftermarket fuel pump....
stock injectors though....but my narrowband a/f reader shows super rich even when i just throttle on a bit....

 

[m1adam]

Maybe 2 rich,dats why plugs cant burn all the fuel properly causing carbon deposits on the plugs thusn reduce the plugs efficiency to produce spark at the correct specs.Usually misfiring is unburnt fuel combusting through compression not through spark.

 

[tuned]

hmmm true....

maybe i'll get a piggyback and fpr 1st.....used to have a piggyback...but stolen last month.....

thanks anyway...

 

[jinkl]

if its nt all tht then its ur cam angle sensor
most probably retards or advances

 

[tuned]

hi there jinkl,

a mech told me that too...
could be my cam or crank sensor which is screwed up...especially when it only happens at certain RPM point...

u had the same problem b4?

 

[jinkl]

hi there jinkl,

a mech told me that too...
could be my cam or crank sensor which is screwed up...especially when it only happens at certain RPM point...

u had the same problem b4?

yeaps , lucky i had a spare , fixed it in
r u using standard ecu or standalone ?
if ur car is standalone n its using map sensor , then the fault could be on the hose
that goes to map sensor , either leaking or loose

 

[tuned]

ohh so u mean its possible the cam sensor's actually screwed up....
hmm...going to get my timing belt change..hence might wanna change that..
any idea how much's that sensor?....my mech was recommending to change the crank sensor too...is that necessary?

anyway i'm currently on stock ECU with MAF.....

 

[jinkl]

oh ok , i dint know ur car runs on crank sensor
i guess u wouldnt have the cam angle then

 

[tuned]

erm not sure.... myself...

but its one of the possibilities i understand from my mech...

cam / crank sensor... do u mean usually engines would only have either one of them?

 

[RSI]

check your fuel pump. It may not be sustaining pressure at higher engine output.

 

[tuned]

thanks for the tip dude...

the fuel pump's been upgraded to a hi-flo unit....

btw, the misfiring problem's solved...sorry for not updating...

found out..jinkl's suggestion was right....the cam sensor was faulty...

now it works fine.....