Strange hestitation/stumble from 2700-2900rpms
04-16-2004, 12:18 PM
#1
Not DAVEB the parts guy
Thread Starter
Join Date: Aug 2000
Posts: 8,555
Strange hestitation/stumble from 2700-2900rpms
I searched Org and can't find anything concerning my problem. For the past 10 days, my Maxipad has developed an odd stumble/hestitation problem from 2700-2900rpms under very light throttle. This stumble is really felt when I'm accelerating very mildly in 1st or 2nd gear. It's sometimes noticable in 3rd or 4th, but the lower gears seem worse. The stumble feels exactly like if I engage my MEVI way to early, like 4500rpms. This results in a loss of ~15fwhp on the dyno and according to my butt dyno, this stumble feels like the same type of loss. I am running a PR-style CAI. Prior to that I was running a hacked airbox with midpipe and the VQ would have a very slight stumble in the mid 3000rpm range. Could the CAI somehow move this stumble down in the rpms?
Things I've noted:
1) When the engine is cold, it doesn't do the stumble
2) As the engine gets progressively warmer, the stumble becomes more apparant
3) If I'm idling for a long period of time, the stumble is more apparant
4) I can completely avoid the stumble by adding ~30% throttle
5) As the temps are rising in KC (85 degrees today) the stumble becomes more apparant
6) The car pulls completely fine from idle to 2700rpms and 3000rpms+
7) I have replaced my plugs that exhibited a slightly lean condition (NGK coppers), checked the coil packs, inspected the PVC valve, checked all grounds, ran a vacuum test, checked the TPS sensor, cleaned the MAF elements. Everything checks out.
My only other option is my MAF connector. A month ago my MAF ground wire became severed from the inside of the connector. I ended up stuffing the ground wire into the connector and secured the wire with tape. I have a replacement connector arriving next week that I will solder in. When the wire broke, the car sounded like a Harley and was undriveable. After I jammed the wire in there, it ran great and with no stumble. I guess it's very possible that the connection could be just weak enough to run fine most of the time.
I plan on using my OBDII scanner to watch and datalog my sensors to watch any strange readings.
Anyone else experience this stumble or have figured out a way to fix it?
Dave
Things I've noted:
1) When the engine is cold, it doesn't do the stumble
2) As the engine gets progressively warmer, the stumble becomes more apparant
3) If I'm idling for a long period of time, the stumble is more apparant
4) I can completely avoid the stumble by adding ~30% throttle
5) As the temps are rising in KC (85 degrees today) the stumble becomes more apparant
6) The car pulls completely fine from idle to 2700rpms and 3000rpms+
7) I have replaced my plugs that exhibited a slightly lean condition (NGK coppers), checked the coil packs, inspected the PVC valve, checked all grounds, ran a vacuum test, checked the TPS sensor, cleaned the MAF elements. Everything checks out.
My only other option is my MAF connector. A month ago my MAF ground wire became severed from the inside of the connector. I ended up stuffing the ground wire into the connector and secured the wire with tape. I have a replacement connector arriving next week that I will solder in. When the wire broke, the car sounded like a Harley and was undriveable. After I jammed the wire in there, it ran great and with no stumble. I guess it's very possible that the connection could be just weak enough to run fine most of the time.
I plan on using my OBDII scanner to watch and datalog my sensors to watch any strange readings.
Anyone else experience this stumble or have figured out a way to fix it?
Dave
04-16-2004, 12:23 PM
#2
lol dang dave.........that my problem too cept mine does it at varying rpms. But my car also feels weeker.....I replaced the injectors per your suggestion.....changed fuel filters, pvc, and plugs. My coil packs are only about 8 months old.
I had a knock sensor code....which I think if my issue. Perhaps it is yours too. Your symptoms of when it happens though are100% inline with me.
I had a knock sensor code....which I think if my issue. Perhaps it is yours too. Your symptoms of when it happens though are100% inline with me.
04-16-2004, 12:25 PM
#3
The only stumble I ever had was intermittent between rpms and mostly while I was WOT. Of course it was a bad coil pack. I highly doubt it is that though.
Have you checked your injectors as well...just to be safe?
I would hesitate doing much more testing until you get that replacement MAF connector.
I know someone on here has more insight...
Have you checked your injectors as well...just to be safe?
I would hesitate doing much more testing until you get that replacement MAF connector.
I know someone on here has more insight...
04-16-2004, 02:56 PM
#5
Guest
Posts: n/a
Dave, I swear I had the same problems you listed in 1 thru 7 when one of my coil packs was going bad.
Notice I said "was going". Although you tested the coils, I can nearly guarantee that it's indeed your coil(s). Remember that only a completely, or nearly completely deteriorated coil will show as defective when you test it. Since the hesitations are only from 2700 to 3000 as you describe, coil testing of a slightly defective coil will yield nothing. In other words, testing a slightly deteriorated coil which gives in the 2700-3000 rpm range will, in most cases, show it as a perfectly working coil. I say this because I too had very slight hesitations in this SAME EXACT range: 2700-3000, and after testing all coils, I noticed that every single one was perfect (that is, it provided the necessary wattage), when indeed one WAS NOT.
However, every slightly-defective coil will, sooner or later, deteriorate to a state where it causes SEVERE cylinder misfires.
As far as I know, you can get your hands on coil packs easily because you got a dealer hook up, right? Anyway, get one new coil pack and keep swapping it with others until the hesitations at idle and in the 2700-3000 range stop. That's what I did, and that it how I found which coil had to be replaced.
Notice I said "was going". Although you tested the coils, I can nearly guarantee that it's indeed your coil(s). Remember that only a completely, or nearly completely deteriorated coil will show as defective when you test it. Since the hesitations are only from 2700 to 3000 as you describe, coil testing of a slightly defective coil will yield nothing. In other words, testing a slightly deteriorated coil which gives in the 2700-3000 rpm range will, in most cases, show it as a perfectly working coil. I say this because I too had very slight hesitations in this SAME EXACT range: 2700-3000, and after testing all coils, I noticed that every single one was perfect (that is, it provided the necessary wattage), when indeed one WAS NOT.
However, every slightly-defective coil will, sooner or later, deteriorate to a state where it causes SEVERE cylinder misfires.
As far as I know, you can get your hands on coil packs easily because you got a dealer hook up, right? Anyway, get one new coil pack and keep swapping it with others until the hesitations at idle and in the 2700-3000 range stop. That's what I did, and that it how I found which coil had to be replaced.
04-16-2004, 03:03 PM
#6
Senior Member
Join Date: Mar 2004
Posts: 419
thats really wierd, cause my car does the same thing, but instead of between 2700-2900, mine is more 3500-4000, i dont understand it, but im thinkin its the coil packs on mine, cause with 100,000 miles, things tend to go bad.
i would like to know what you did, cause im kinda new to the maxima scene, 4 months, but im lovin it so far.
i would like to know what you did, cause im kinda new to the maxima scene, 4 months, but im lovin it so far.
04-16-2004, 06:48 PM
#7
Yup. Felt the same thing today. I'm in the 3300-3800 range, in 3rd gear. It's really annoying. It happens at partial trottle. I'll accelerate and the rpm will drop a couple hundred and then rise again... bump... I've noticed it a long time ago, but ever since I installed bomz intake, it's become very apparent.
Coil packs... hmmm... let's see where this goes.
Coil packs... hmmm... let's see where this goes.
04-16-2004, 07:33 PM
#8
Not DAVEB the parts guy
Thread Starter
Join Date: Aug 2000
Posts: 8,555
Originally Posted by BOSS
Dave, I swear I had the same problems you listed in 1 thru 7 when one of my coil packs was going bad.
Notice I said "was going". Although you tested the coils, I can nearly guarantee that it's indeed your coil(s). Remember that only a completely, or nearly completely deteriorated coil will show as defective when you test it. Since the hesitations are only from 2700 to 3000 as you describe, coil testing of a slightly defective coil will yield nothing. In other words, testing a slightly deteriorated coil which gives in the 2700-3000 rpm range will, in most cases, show it as a perfectly working coil. I say this because I too had very slight hesitations in this SAME EXACT range: 2700-3000, and after testing all coils, I noticed that every single one was perfect (that is, it provided the necessary wattage), when indeed one WAS NOT.
However, every slightly-defective coil will, sooner or later, deteriorate to a state where it causes SEVERE cylinder misfires.
As far as I know, you can get your hands on coil packs easily because you got a dealer hook up, right? Anyway, get one new coil pack and keep swapping it with others until the hesitations at idle and in the 2700-3000 range stop. That's what I did, and that it how I found which coil had to be replaced.
Notice I said "was going". Although you tested the coils, I can nearly guarantee that it's indeed your coil(s). Remember that only a completely, or nearly completely deteriorated coil will show as defective when you test it. Since the hesitations are only from 2700 to 3000 as you describe, coil testing of a slightly defective coil will yield nothing. In other words, testing a slightly deteriorated coil which gives in the 2700-3000 rpm range will, in most cases, show it as a perfectly working coil. I say this because I too had very slight hesitations in this SAME EXACT range: 2700-3000, and after testing all coils, I noticed that every single one was perfect (that is, it provided the necessary wattage), when indeed one WAS NOT.
However, every slightly-defective coil will, sooner or later, deteriorate to a state where it causes SEVERE cylinder misfires.
As far as I know, you can get your hands on coil packs easily because you got a dealer hook up, right? Anyway, get one new coil pack and keep swapping it with others until the hesitations at idle and in the 2700-3000 range stop. That's what I did, and that it how I found which coil had to be replaced.
I have a friend with a brand new coil pack he isn't using and I'm pretty sure he'll let me borrow it and probably buy it from him. It will take a little while, but I guess I could test coil by coil with a test drive. I'd love to know that it's something simple as a coil.
Dave
04-17-2004, 01:52 AM
#10
sounds like ghost 0304 CEL to me. i am guessing the knock sensor is in safe mapping ignition mode. dave...when was the last time you replace your knock sensor? i pull the ECU manually and test out the knock sensor with an ohmmeter.
just my .02
just my .02
04-19-2004, 12:23 PM
#14
Not DAVEB the parts guy
Thread Starter
Join Date: Aug 2000
Posts: 8,555
Preliminary results
I was able to borrow a brand new unused coil pack from a local owner. I decided to replace the coil for cylinder #2 since that coil had slightly more resistance than the other coils. After two days of driving, the car runs perfect with absolutely no stumble. No other changes were made. It seems to idle better too and the car feels really strong, but that's probably all in my head. I do have to take into consideration that the weather is a bit cooler (lower 70s, 60% humidity) compared to the lower 80s and high humidity we had late last week. It seemed the stumble got progressively worse as the temps went up. I've tried my best to get the engine super hot (WOT throttle, then stop for 1-2 minutes, then go part throttle) to reflect hotter ambient temps, but even with a scalding hot intake manifold, the stumble appears to be gone.
So as of right now, everything seems to be pointing to the coil pack. I'll give it some more time.
If it turns out to be the coil, I almost wonder if degrading coil packs are responsible for a majority of the idle/driveability/vibrations people are complaining about. I know these things can't last forever, even my 96's supposedly more reliable coils. They're under such extreme heat and voltage it only makes sense that they'll degrade over a period of 5-7 years. Ignition coils and wires on other cars are suppose to be replaced at regular intervals so I don't see why the coil packs amy have to be replaced every 5-7 years.
Dave
I was able to borrow a brand new unused coil pack from a local owner. I decided to replace the coil for cylinder #2 since that coil had slightly more resistance than the other coils. After two days of driving, the car runs perfect with absolutely no stumble. No other changes were made. It seems to idle better too and the car feels really strong, but that's probably all in my head. I do have to take into consideration that the weather is a bit cooler (lower 70s, 60% humidity) compared to the lower 80s and high humidity we had late last week. It seemed the stumble got progressively worse as the temps went up. I've tried my best to get the engine super hot (WOT throttle, then stop for 1-2 minutes, then go part throttle) to reflect hotter ambient temps, but even with a scalding hot intake manifold, the stumble appears to be gone.
So as of right now, everything seems to be pointing to the coil pack. I'll give it some more time.
If it turns out to be the coil, I almost wonder if degrading coil packs are responsible for a majority of the idle/driveability/vibrations people are complaining about. I know these things can't last forever, even my 96's supposedly more reliable coils. They're under such extreme heat and voltage it only makes sense that they'll degrade over a period of 5-7 years. Ignition coils and wires on other cars are suppose to be replaced at regular intervals so I don't see why the coil packs amy have to be replaced every 5-7 years.
Dave
04-19-2004, 12:48 PM
#15
Donating Maxima.org Member
Join Date: Dec 2002
Posts: 2,749
Hmm, i have a similar problem. However it only happens when the motors cold. For instance, i'll start it up, let it run for around 5mins and as the needle rises i begn to drive. I keep shifts under 3K while the engine fully warms. HOWEVER, as i approach...2500rpms my car stumbles, almost hesistating like maybe its not getting enough gas. Lasts until i shift at 3K rpms. This only happens when the motor is cold. Could this be a similar problem? I have a 99 with...*sigh* 102,000 miles 
-Eric
-Eric
04-19-2004, 02:13 PM
#16
Guest
Posts: n/a
Originally Posted by Dave B
Preliminary results...They're under such extreme heat and voltage it only makes sense that they'll degrade over a period of 5-7 years. Ignition coils and wires on other cars are suppose to be replaced at regular intervals so I don't see why the coil packs amy have to be replaced every 5-7 years.
Dave
Dave
sooooooooooo true
03-02-2008, 09:33 AM
#22
Senior Member
Join Date: Mar 2006
Location: Toledo OH
Posts: 170
Preliminary results
I was able to borrow a brand new unused coil pack from a local owner. I decided to replace the coil for cylinder #2 since that coil had slightly more resistance than the other coils. After two days of driving, the car runs perfect with absolutely no stumble. No other changes were made. It seems to idle better too and the car feels really strong, but that's probably all in my head. I do have to take into consideration that the weather is a bit cooler (lower 70s, 60% humidity) compared to the lower 80s and high humidity we had late last week. It seemed the stumble got progressively worse as the temps went up. I've tried my best to get the engine super hot (WOT throttle, then stop for 1-2 minutes, then go part throttle) to reflect hotter ambient temps, but even with a scalding hot intake manifold, the stumble appears to be gone.
So as of right now, everything seems to be pointing to the coil pack. I'll give it some more time.
Dave
I was able to borrow a brand new unused coil pack from a local owner. I decided to replace the coil for cylinder #2 since that coil had slightly more resistance than the other coils. After two days of driving, the car runs perfect with absolutely no stumble. No other changes were made. It seems to idle better too and the car feels really strong, but that's probably all in my head. I do have to take into consideration that the weather is a bit cooler (lower 70s, 60% humidity) compared to the lower 80s and high humidity we had late last week. It seemed the stumble got progressively worse as the temps went up. I've tried my best to get the engine super hot (WOT throttle, then stop for 1-2 minutes, then go part throttle) to reflect hotter ambient temps, but even with a scalding hot intake manifold, the stumble appears to be gone.
So as of right now, everything seems to be pointing to the coil pack. I'll give it some more time.
Dave
If anyone has had this same problem let me know and Dave if the coil pack solves your problem in high humidity let me know also.
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