slight misfire?
08-02-2009, 02:20 PM
#1
3rd Gear Member
Thread Starter
Join Date: Jan 2007
Location: pa
Posts: 613
slight misfire?
all of a sudden it feels like my car has a slight misfire. the plugs and wires are new,the check engine light hasnt come on and its not throwing any codes.
what can be the problem? its not that noticable when car is running,you can feel it when you rev and when your driving.
what can be the problem? its not that noticable when car is running,you can feel it when you rev and when your driving.
08-02-2009, 06:04 PM
#4
3rd Gear Member
Thread Starter
Join Date: Jan 2007
Location: pa
Posts: 613
they are autolite iridium xp plugs and the wires are duralasts from autozone but they have a lifetime warranty i belive. ive had the plugs and wires since i did the pi intake swap over 5k miles ago and its ran great untill now.
i thought it might have had something to do with the drivetrain but it feels like a misfire and i can feel it above 2k rpms in gear or not.
i had it checked at autozone and it didnt throw any codes.
i thought it might have had something to do with the drivetrain but it feels like a misfire and i can feel it above 2k rpms in gear or not.
i had it checked at autozone and it didnt throw any codes.
Last edited by mrxr250rider; 08-02-2009 at 06:10 PM.
08-02-2009, 06:55 PM
#5
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
I would first suspect the wires, the EEC-IVs misfire detection is not all that sohisticated and it would be possible for the spark to be leaking under load and the PCM not detecting the misfire.
Have the wires been disconnected/reconnected since being installed? The Duralast wires have crappy connectors that can get misshapen easily. Open your hood in the dark and see if there's a light-show anywhere--there may not be at idle (and trying to peek under the hood at WOT is difficult) but it might be worth a look.
Also, many iridium plugs have very small/thin electrodes, that produce a high-energy but thin spark your motor was not designed for. You might want to try a set of single platinum electrode plugs (which the engine was designed for) and see if things improve.
Have the wires been disconnected/reconnected since being installed? The Duralast wires have crappy connectors that can get misshapen easily. Open your hood in the dark and see if there's a light-show anywhere--there may not be at idle (and trying to peek under the hood at WOT is difficult) but it might be worth a look.
Also, many iridium plugs have very small/thin electrodes, that produce a high-energy but thin spark your motor was not designed for. You might want to try a set of single platinum electrode plugs (which the engine was designed for) and see if things improve.
08-02-2009, 07:13 PM
#7
3rd Gear Member
Thread Starter
Join Date: Jan 2007
Location: pa
Posts: 613
so it sounds like wires/plugs from my description? just making sure its not a dirty mafs,coil packs ect cause the plugs and wires are new.
i noticed the missfire lastnight after making a WOT run. the car sees WOT enough and never had a problem.
the car also has a vaccum leak which i havent found yet,runs funny with the hvac on and doesnt work well at all except for defrosting the windows. figured id throw that in there incase it may have something to do with my problem.
i noticed the missfire lastnight after making a WOT run. the car sees WOT enough and never had a problem.
the car also has a vaccum leak which i havent found yet,runs funny with the hvac on and doesnt work well at all except for defrosting the windows. figured id throw that in there incase it may have something to do with my problem.
Last edited by mrxr250rider; 08-02-2009 at 07:20 PM.
08-02-2009, 07:19 PM
#8
3rd Gear Member
Thread Starter
Join Date: Jan 2007
Location: pa
Posts: 613
i havent noticed that but anywhere after 2k rpms i can feel the vibration/roughness from the missfire and its not running like it should but it doesnt feel like i lost alot of power.
08-02-2009, 07:46 PM
#9
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
08-02-2009, 08:06 PM
#10
3rd Gear Member
Thread Starter
Join Date: Jan 2007
Location: pa
Posts: 613
after not hearing anything good about duralast wires i wouldnt doubt thats my problem.
didnt want them in the first place but needed new wires bad(soaked with coolant after the intake cracked) and my dad took the car down the autozone and put in the wires.
i think they have a lifetime warranty so i might just get them replaced for now and save up for screaming demon coils and plugs.
didnt want them in the first place but needed new wires bad(soaked with coolant after the intake cracked) and my dad took the car down the autozone and put in the wires.
i think they have a lifetime warranty so i might just get them replaced for now and save up for screaming demon coils and plugs.
Last edited by mrxr250rider; 08-02-2009 at 08:13 PM.