hello.
i have a 99 maxima that has a misfire at idle. i changed out the plugs and all were looking good. also checked all the coils and they all have a proper reading. there were no codes in the ECM...any thoughts on what could be causing this misfire at idle...kinda odd that the ECM would not pick this up...thanks
My bet is a bad coil, correct resistance or not.
yeah that's kinda what I am thinking, but why would the SES light not come on with a misfire? and why is it doing it only intermittently at idle??
first things first,
If you replaced the plugs with anything other than NGK platinum plugs that is mistake number one, you need to use NGK platinum plugs, not NGK copper or any of that other crap, you need to use exactly what is calls for.
if the problem persists then I would look at the coils as the next probable cause
i am using NGK iridium plugs, it had NGK platinums in it before, but it misfired with the platinums too.. i am starting to think there might be a problem with electricity getting to the coils, cause it usually only misfires when i am sitting at a traffic light at night with my headlights and foglights on...all the posts i've read about bad coils always showed up a code in the ECM..
Hi all - speaking of misfires, what does it sound/feel like? I'm having trouble with my 97 Max, and not sure if it is misfiring.
Thanks!
snipped-for-privacy@yahoo.com wrote:
Ok , you NGK plugs in it.
I know I'm splitting hairs here but, you should put the Platinum's in it.
Was the missfire condition present before you changed the plugs ?
hi, yeah it was misfiring with the platinums too...still confused why the SES light is not coming on...i read somewhere that a fault has to occur at least 3 times in a cycle before the SES will come on..i think that was for the EVAP though (gas cap not tight), does this apply for a misfire too?..i think that's kinda how it goes... i am actually starting to think that there might be a problem with the battery.. is there anything besides plugs/coils that would cause a misfire at idle only? i am still pondering over the electricity thing though. surely a bad injector would throw a code...
on a different note, what is the purpose of the WOT/closed throttle switch inside the TPS? i read in the shop manual that it does not affect anything as far as engine control is concerned, so i am guessing its purely for the TCM.(althought the wiring diagram shows it going to the TCM and ECM)..my max is affected by the throttle shock problem when letting off the gas (there is a TSB out for it and it calls for a new TCM). i disconnected the connector for the WOT/closed throttle switch and the throttle shock problem is gone...there are no codes showing up when i ran the car with it disconnected for 3 days, but i reconnected it since it must have some sort of purpose. i ran the max in all kinds of conditions and it doesn't act abnormal or anything (execpt the misfire at idle, but its not related)...thanks for all the help....
hi, yeah it was misfiring with the platinums too...still confused why the SES light is not coming on...i read somewhere that a fault has to occur at least 3 times in a cycle before the SES will come on..i think that was for the EVAP though (gas cap not tight), does this apply for a misfire too?..i think that's kinda how it goes... i am actually starting to think that there might be a problem with the battery.. is there anything besides plugs/coils that would cause a misfire at idle only? i am still pondering over the electricity thing though. surely a bad injector would throw a code...
on a different note, what is the purpose of the WOT/closed throttle switch inside the TPS? i read in the shop manual that it does not affect anything as far as engine control is concerned, so i am guessing its purely for the TCM.(althought the wiring diagram shows it going to the TCM and ECM)..my max is affected by the throttle shock problem when letting off the gas (there is a TSB out for it and it calls for a new TCM). i disconnected the connector for the WOT/closed throttle switch and the throttle shock problem is gone...there are no codes showing up when i ran the car with it disconnected for 3 days, but i reconnected it since it must have some sort of purpose. i ran the max in all kinds of conditions and it doesn't act abnormal or anything (execpt the misfire at idle, but its not related)...thanks for all the help....
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