NAN777

Hi,

i have a wierd situation here. i just changed my exhaust... previously i'm using 3 inch.. now i'm still with 3 inch but just a better flowing exhaust... right after i change, i notice my boost hit the limit where my boost controller beeps at 1 bar. so i set to 1.1 bar.. and inside the PFC, boost limit is set to 1.2 bar.. just incase i hit 1 bar again..

then it was rock solid.... steady 0.85 bar...

when i was doing WOT.. there are some jerking going on.. like not smooth... never had that situation before.... just after changing exhaust... so, i tot it might be worn spark plugs.... so i haven't get my air fuel checked yet...

then i change my plugs to Denso S31A plugs all 4 of them... and just now i went for a drive.. it feels smooth.. it's a heat range 10 plugs... on sudden WOT throttle... i had a massive mis firing....the boost looks okay but a little vibration... but the car won't go.. just keep mis firing...

as i slow throttle to WOT... i have the jerking feel.... but i won't have problem when running lower boost like 0.7.... what should i start looking at ?

Narfle

iTrader: (16)

Sounds like your ignition system is failing. Perhaps the stock coils are not good enough.

Mahjik

iTrader: (1)

There is a ground wire which attaches to the exhaust. Did you re-attach this when you did your swap?

NAN777

i don't recall any ground wire.. it look like an EGT sensor to me... it's like a stick fastened into the exhaust mid pipe.

if it's the ignition coil.. it's gonna be pain in the ***...

NAN777

probably my air flow is suddenly increased. i managed to get around by using the accelerate injector portion increasing the value for 4000 and 5000 rpm... to 8.0 and increase the decay to 1.2 and 1.3.... the problem disappeared... the only difference is that i have a passenger after i set it...dun how much it will differ..

NAN777

the problem still exist. changed fuel. felt better. but first gear still have problem. only changed plugs to denso s31. power fc adjust doesnt work.

anyone got exp on denso s31 plugs?

NAN777

crap... i'm hearing knock... just now when i was driving it.... 1st gear didn't went well.. up to 2nd gear.. it went up well.. then 3rd gear.... went up to 6000 rpm.. i heard knocking sound.. like some rattling.. immediately i back off....

tomorrow i'm going to do a check on the plug cables if anything gone wrong with it or wrongly plugged during the plug change....

before that.. what else should i check ? i hope i didn't damage any electrical cables nearby while taking out the plugs..

1) plug cables

what else ?
things that i can't check

1) coils
2) electrical harness nearby

NAN777

hmmm it seems like problem solved.. today i took out the intake piping connecting the UIM... got it cleaned by spraying carb cleaner on them... and found out that the boost sensor's connection is loose.. the vacuum hose seems just snugly fitted on it... so i replaced a new one...

and then double check the connection of plugs... making sure it snap right back in... making sure it wasn't wrongly connected...

and whala... i did a 1st gear test.. no issue.. i hope it's solved.... hopeeeeeeeeeee