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randomly losing spark?
Posted: Sat Mar 24, 2007 12:02 pm
by scttydb411
k20a2
fullrace kit
550cc inj
ngk plugs
tuned low cams out then began hicams...after a few wot runs w/ both cams engaging it randomly starts losing spark and going pig rich after 6k. thought it was the autolite plugs cust was using so he changed to a new set (unfortuneately autolites again). it pulled fine once and then kept losing spark after 6k again. changed to ngk's and ran fine for a pull and then after that lost spark again after 6k. it has lost usb connectivity once, but usually can keep connectivity all the time.
bolts are on coils btw.
any ideas?
Posted: Sun Mar 25, 2007 7:08 am
by QUICKSILVER RACING
sounds like a misfire.
try setting the vtec to 8000 first then tune. check if it goes away.
if it doesn't, post calibration and datalog
Posted: Sun Mar 25, 2007 12:46 pm
by scttydb411
i already tuned locam out to 7k then enabled hicam and had a few clean pulls. the datalogs don't show the misfire as knock. the honda o2 shows to be .5-1.0 af pt off in wot than the dyno wideband and i've found that to be the case with the honda k-series o2. dyno af readings were 12.0-12.5 across during a clean run and then dumping out after 6k.
it's definately losing spark, but how? changed plugs twice and finally to ngk from the autolites the cust had. made sure the coil plugs were bolted down. timing still conservative. it just doesn't make sense that we would get a clean run then the run directly after that craps out w/o any major changes to the map.
i've seen on older hondas (i know different ignition system) crap out with a bad ignitor, but is this something that occurs w/ the coils on k-series?
Posted: Sun Mar 25, 2007 1:18 pm
by Razathorn
QUICKSILVER RACING wrote:sounds like a misfire.
try setting the vtec to 8000 first then tune. check if it goes away.
if it doesn't, post calibration and datalog
Vtec at 8k may damage the motor.

Posted: Tue Mar 27, 2007 6:40 am
by QUICKSILVER RACING
Razathorn wrote:QUICKSILVER RACING wrote:sounds like a misfire.
try setting the vtec to 8000 first then tune. check if it goes away.
if it doesn't, post calibration and datalog
Vtec at 8k may damage the motor.

the problem is at 6k rpm. setting the vtec at 8k rpm doesn't mean you will run your car up 8k rpm.
you will check if the same problem occurs at 6k rpm.
please use common sense.
Posted: Sat Mar 31, 2007 4:30 pm
by scttydb411
anyone else?