4g63t missfire.. help!!

[nan83]

hi all.... now i still troubleshooting my missfiring prob....

on idle = smooth
accelerate = smooth
boosting = smooth

misfire only at above 4000rpm while part throttle or maintain rpm... it happen at all gear while cruising at above 4000rpm.... while the misfire happen, i see the temp gauge is fluctuating , the needle go up & down, but it not go below 70'c & above 95'c lah....

i already check :
1. cable plug resistant not above 400ohm...
2. plug gap 0.7mm
3. change cas sensor
4. bypass ignition module..... run direct from e6x to dynatec arc to coil.. still missfire...
5. check all ground wire (ecu & sensors)
6. check wiring to injector & coil
7. check injector resistance...
8. intake manifold & banana no leak.. ( only small leak at TB shaft seal )

all above i check no prob, but misfire still there... make me penin... huhuhu

thing still not done :
- ignition coil still not replace
- fuel filter still not change
- injector still not sonic clean

what inside my head know is :
- injector not balance...
- electrical prob (interference or something)... it make my temp gauge fluctuate & missfire

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the ign timing & fuel map i already tune.... try lean, try rich afr... still missfire... try advance & retard timing also missfire... make me mad.... huhuhu

my car spec:
4g64 block with fairlady piston
tomei 260 dynatec ignition
PE 1000cc injector

huummm..... my fairlady piston low about 2mm from block... can it cause missfire???? my car also dun like to tune at stoich while cruising.... need to set 13-12:1 afr to smooth it... huhuhuhu.... pening2 hope all can give input about my prob... thanks all!!!

 

[AlucarD]

Could be your Dynatec ARCII, Try switching off restrike option. If that does not work check colis. R us using 300m coils or standard coils?? The 300m coils require you to gap them slightly closer. If it does not work go back to ori ignition without ARCII and see if same prob appears. If no problem the your ARCII is the culprit. Send it back to Raymond of Dynatec for service. Good luck :)

 

[nan83]

thanks alucarD .... yah already test restrike off... the prob still there.... i only use stock evo coil.... i will try replace the coil first...

about the dynatec.... it quite hot, need to install heatsink & fan... scare heat will short it lifespan...

 

[AlucarD]

Errr... what evo model is urs? The E1-3 can use back ori coils but E4-9 have to use different coils to enable the ARCII to work as you could not amplify the E4-9 coils since it has a build in resistor. Your ARCII should not be very hot. It will misfire if the unit gets too hot. I have previously build heat sinks with 2 fans but still do not work once it gets too hot. Only option is to send back to dynatek. They had some problems with the earlier ARCII units. But confirm its the unit fault first by going back to ori ignition. If ori no problem then its the ARCII lo. Where you got your unit from??

 

[nan83]

emm.. i use 2.4block, vr4 head + evo3 wiring.... i got my arc2 from Extreme PSI, it already come with plug&play harness for dsm & evo1-3.... but i already mod the harness, coz i want the unit inside the car.. the ori harness to short & must install beside timingbelt.... yr arc2 install to what car??

 

[flanker c]

actually misfire frequently cause by ignition not balance..what cold step spark plug you use? plug gap should 0.5-0.6mm for 1 step cold no 8 plug..0.7mm gap too far maybe cause missfire..try re-gap to 0.6mm...mine got kena same case like you..lastly re-gap 0.6mm problem solve..no more missfire issue.

 

[mnj83]

nan83..u can try as per flanker c said..i think that can solve your prob....huhuhu

 

[nan83]

thanks all... i will try & will update if it solve the prob..... but i already use CDI, so it should be no prob with big gap... 2 more day i'm back home & troubleshoot it...

 

[AlucarD]

Nan83, I have used both ARCII on my 4G93T and my 4G63T. Have tried with both idividual coils and stock coils. Hmm, actually with CDI ignition you seldom need to regap to closer. Infact you can use stock gap or regap to wider!! Take advantage of the CDI and make more power. The ARCII has a restrike feature as well so dont see the need to regap closer. How about your dwell time?? Although CDI dont need any dwell time. It still need some from of dwell timing. Did you check if your ecu sending the dwell timing to the CDI. I stilll prefer to run the CDI from the ignitor rather direct from the ECU. If anything goes wrong it will screw/burn the ignitor first and I'll know the culprit. Unless you're doing sequential injection la :P

 

[ehdrian]

AlucarD taikor mmg pro, i dun understand a single thing u guys discussing..hehe

 

[nan83]

the dwell time i already decrease from 3.8ms to 1ms .... 3.8ms while using stock coil with no cdi.... yaa, i already know the power of cdi, gap wider than std oso no prob... huhu

huumm... i oso run with ignitor... i'm bypass it coz wanna test it only....