Anyone getting a "hot" misfire.
Thread Starter
Junior Member
Joined: Nov 2013
Posts: 20
Anyone getting a "hot" misfire.
I'm getting a progressively worse misfire as engine temps rise.
Short (less than 10 miles) drives I just started getting a load related miss. It isn't engine RPM but throttle position. I can feather the throttle around 3/4 with the trans held in gear and get a good solid pull until I get past said throttle position then power drops and you get that washboard sensation of a high RPM miss. So by feathering it - the miss can be basically switched on and off like a lightbulb.
As the drive time increases (and especially if I drive it hard) - the miss works it's way down the throttle range until it is stumbling at idle and tip in - with an obvious dead miss at low RPM that makes the car go thud-thud-thud as it accelerates ...but not so evenly rhythmic - it is more random.
When it is just starting to miss, if I go WOT the engine will fall on it's face for a couple seconds, then it will hook up and pull / but it isn't an even pull, power output fluctuates.
When it isn't missing, if the engine hasn't run more than 20 minutes... and you aren't giving it too hard of throttle, it drives completely normal. You actually get a pretty good acceleration pull until you throttle past a certain point, then power will actaully decrease.
95Max, auto, 215K.
Fuel Filter, Spark Plugs, Coolant Temp sensor all replaced about a year ago.
Other maintenance I am unaware since PO has no records...
Short (less than 10 miles) drives I just started getting a load related miss. It isn't engine RPM but throttle position. I can feather the throttle around 3/4 with the trans held in gear and get a good solid pull until I get past said throttle position then power drops and you get that washboard sensation of a high RPM miss. So by feathering it - the miss can be basically switched on and off like a lightbulb.
As the drive time increases (and especially if I drive it hard) - the miss works it's way down the throttle range until it is stumbling at idle and tip in - with an obvious dead miss at low RPM that makes the car go thud-thud-thud as it accelerates ...but not so evenly rhythmic - it is more random.
When it is just starting to miss, if I go WOT the engine will fall on it's face for a couple seconds, then it will hook up and pull / but it isn't an even pull, power output fluctuates.
When it isn't missing, if the engine hasn't run more than 20 minutes... and you aren't giving it too hard of throttle, it drives completely normal. You actually get a pretty good acceleration pull until you throttle past a certain point, then power will actaully decrease.
95Max, auto, 215K.
Fuel Filter, Spark Plugs, Coolant Temp sensor all replaced about a year ago.
Other maintenance I am unaware since PO has no records...
Last edited by jmlee44; Jan 14, 2015 at 08:05 AM.
Member who somehow became The President of The SE-L Club
iTrader: (19)
Joined: Jun 2001
Posts: 16,024
You have a failing coil pack. As it gets hot, the spark gets weaker and literally gets blown out earlier. Same applies to being able to drive OK by feathering the throttle. The more you get into the throttle, the more load, the spark isn't hot enough and gets blown out.
Unplug the coils one at a time and until you find the one that doesn't cause a 2nd misfire as you put the engine under a load.
Unplug the coils one at a time and until you find the one that doesn't cause a 2nd misfire as you put the engine under a load.
Thread Starter
Junior Member
Joined: Nov 2013
Posts: 20
Ok I'll check the coils. Would this be something that I can check with an OHM meter? It is difficult to put that much load on it unless i Unplug, drive, unplug, drive etc...
I have had codes for downstream o2 and Evap purge something or another since I have owned it.
When I checked yesterday I also had 0302 insufficient EGR, I wouldn't think insufficient EGR would cause this would it? Honestly I'm not sure how long that code has been present since the check engine light is always on for the other two.
I have had codes for downstream o2 and Evap purge something or another since I have owned it.
When I checked yesterday I also had 0302 insufficient EGR, I wouldn't think insufficient EGR would cause this would it? Honestly I'm not sure how long that code has been present since the check engine light is always on for the other two.
Member who somehow became The President of The SE-L Club
iTrader: (19)
Joined: Jun 2001
Posts: 16,024
Get the misfire fixed first, that might be playing havoc on the O2 levels in the exhaust.
You can ohm them and get lucky finding one that's totally out. Give that a shot.
The EGR is a common issue, just clean the EGR pipe from the valve to the upper intake, next to the throttle body.
You can ohm them and get lucky finding one that's totally out. Give that a shot.
The EGR is a common issue, just clean the EGR pipe from the valve to the upper intake, next to the throttle body.
Thread
Thread Starter
Forum
Replies
Last Post
Juki5536
4th Generation Maxima (1995-1999)
3
Oct 24, 2004 06:16 PM