Weird Misfire ~3K - Both coil packs...?
Dec 11, 2008, 06:54 AM
#1
Weird Misfire ~3K - Both coil packs...?
Hello,
Basically in the past three weeks, i've gone through two sets of spark plugs. A set of IK27's and a set of Ik24's.
First it took me about a week and a half to go through the 27's then a about a business week to go through the 24's.
I got to change the 27's before things got real bad, but Saturday night i was driving on the hwy. A/F was fine. Then all of a sudden the car starts bucking like crazy and A/F goes to 10.0. So i put the car in neutral and revved it (trying to clear the plugs) and it worked for a little bit (prob less than a mile). Eventually that was it car couldn't even free rev.
So i towed the car home and took out the plugs.
Basically the IK27's, 24's and a set of BPR8ES plugs look just like above.
After i took the plugs out i bought a few BPR8ES plugs since they are cheap to use till i figure out whats wrong.
I installed the new plugs and it would barely idle and would drive smooth until about 3K then the a/f goes to 10.0 and it bucks like hell. I assume it starts bucking as soon as you start putting load on the car or coming out of vacuum.
I tried unplugging each coil separately to see if one was just dead. But disconnecting them made a difference (sounds obvious that the car is running on two cylinders) and when both are connected the car sounds as it should. But no idle and any load causes the car to go 10.0.
The BPR8ES plugs i just installed look like the picture above after only a few minutes (really less) of driving which was out of my garage around the block and back.
I'm trying to find a set of other stock coils to see if mine are bad but thing is they aren't dead. Can it be possible that they are going out?
Has anyone seen this before? Right now i am not even sure if its the coils... But something is causing the car to go rich or the spark is so weak that the unburnt fuel is causing the plugs to foul out. Even on new plugs the car won't rev in gear past ~3k. But on new plugs it will free rev normally in neutral.
Car has stock coils, HKS DLI II, AEM.
I also tried driving the car without the DLI and it does the same thing. So its not the DLI.
I also don't want to go out and buy new coils or a COP system if that isn't the issue.
Basically in the past three weeks, i've gone through two sets of spark plugs. A set of IK27's and a set of Ik24's.
First it took me about a week and a half to go through the 27's then a about a business week to go through the 24's.
I got to change the 27's before things got real bad, but Saturday night i was driving on the hwy. A/F was fine. Then all of a sudden the car starts bucking like crazy and A/F goes to 10.0. So i put the car in neutral and revved it (trying to clear the plugs) and it worked for a little bit (prob less than a mile). Eventually that was it car couldn't even free rev.
So i towed the car home and took out the plugs.
Basically the IK27's, 24's and a set of BPR8ES plugs look just like above.
After i took the plugs out i bought a few BPR8ES plugs since they are cheap to use till i figure out whats wrong.
I installed the new plugs and it would barely idle and would drive smooth until about 3K then the a/f goes to 10.0 and it bucks like hell. I assume it starts bucking as soon as you start putting load on the car or coming out of vacuum.
I tried unplugging each coil separately to see if one was just dead. But disconnecting them made a difference (sounds obvious that the car is running on two cylinders) and when both are connected the car sounds as it should. But no idle and any load causes the car to go 10.0.
The BPR8ES plugs i just installed look like the picture above after only a few minutes (really less) of driving which was out of my garage around the block and back.
I'm trying to find a set of other stock coils to see if mine are bad but thing is they aren't dead. Can it be possible that they are going out?
Has anyone seen this before? Right now i am not even sure if its the coils... But something is causing the car to go rich or the spark is so weak that the unburnt fuel is causing the plugs to foul out. Even on new plugs the car won't rev in gear past ~3k. But on new plugs it will free rev normally in neutral.
Car has stock coils, HKS DLI II, AEM.
I also tried driving the car without the DLI and it does the same thing. So its not the DLI.
I also don't want to go out and buy new coils or a COP system if that isn't the issue.
Last edited by Jean; Dec 11, 2008 at 06:59 AM.
Dec 11, 2008, 09:32 AM
#3
IE: It's not idling like it should but its not turning off. When you start driving low load or under 3k it drives fine a/f and oil pressure is fine.
Now while its bucking the a/f goes to 10.0 and it starts to buck the dash lights dim and the oil pressure slightly drops like its shutting off. I either go up a gear and it does the same or let it coast while holding the throttle slightly so it doesn't turn off.
Something is definitely causing the car to either dump way too much fuel or the spark to too weak to burn the fuel. But the coils aren't dead, i am not sure if they just send weak signals while its on its way out.
Sadly till i put in another set of coils i won't be sure, wanted to see if this happened to anyone else before.
Last edited by Jean; Dec 11, 2008 at 09:34 AM.
Dec 11, 2008, 01:48 PM
#4
No they go richer. As if there is no spark. Its not just misfire sounds, it starts bucking like crazy and the car wants to shut off.
IE: It's not idling like it should but its not turning off. When you start driving low load or under 3k it drives fine a/f and oil pressure is fine.
Now while its bucking the a/f goes to 10.0 and it starts to buck the dash lights dim and the oil pressure slightly drops like its shutting off. I either go up a gear and it does the same or let it coast while holding the throttle slightly so it doesn't turn off.
Something is definitely causing the car to either dump way too much fuel or the spark to too weak to burn the fuel. But the coils aren't dead, i am not sure if they just send weak signals while its on its way out.
Sadly till i put in another set of coils i won't be sure, wanted to see if this happened to anyone else before.
IE: It's not idling like it should but its not turning off. When you start driving low load or under 3k it drives fine a/f and oil pressure is fine.
Now while its bucking the a/f goes to 10.0 and it starts to buck the dash lights dim and the oil pressure slightly drops like its shutting off. I either go up a gear and it does the same or let it coast while holding the throttle slightly so it doesn't turn off.
Something is definitely causing the car to either dump way too much fuel or the spark to too weak to burn the fuel. But the coils aren't dead, i am not sure if they just send weak signals while its on its way out.
Sadly till i put in another set of coils i won't be sure, wanted to see if this happened to anyone else before.
AFR gauges don't read the amount fuel you put in they read the oxygen left. Just think about it you don't burn up the oxygen in a missfire so there is more O2 left in the exhaust gasses meaning it looks/appears to be leaner.
I wager your dumping fuel in and it can't ignite the mixture sometimes making it buck. Its probably even richer than you realize depending how often the ignition can actually ignite the mixture.
Dec 11, 2008, 07:28 PM
#7
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this may sound dumb, but i had a major problem like this for nearly 4 months. the dealerships could not find the cause of the misfire. I suspected ignition problems....... either way i read somewhere to check for small splits in your spark plug boots. I found them in mine and replaced the boots and problem solved. Look for a white residue on the outside of the splits. This is caused by the spark leaving the boot before it gets to the plug.
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