PhillyDonut;7878478]1998 I30, 135K, Auto (stock drivetrain)
New battery and starter less than 2 months ago - not related to this.

Recently I’ve been experiencing random hesitation –it does not always happen. I only feel it when the car is in ‘D’ and completely stopped, say at a light. I do not feel it when moving or when in ‘P’ or ‘N’, though did not notice ‘R’. The feeling is similar to someone bumping me in the back; a quick and slight jerk in like less than a second and all is ok. I could image it may be a cyclinder misfiring or something <<guessing here>>. I have a Scangauge2 and it does not show any abnormal dips in RPM (nor does the RPM tach), partly I think it is b/c it occurs so fast that it may not register since the Scangauge2 has a 1 sec delay.

I don’t have a CEL (ok, I do have two codes for something else that I have not yet fix, but these two come and go, been over a year ) related to this. I am leaning toward a vacum leak or potentially failing coil pack but not sure which way to tackle. Has anyone experience something like this to give me some direction?

Questions:
What is it like to have a coil pack GOING bad?
Anyone try cleaning their coil pack?

Coil Pack on it's way out.

But I'm pretty sure mine is an O2 sensor since I have a P0130 code.

Does it happena t all times (cold engine, warm engine, stopped on flat surface vs on incline/decline, etc)

You might want to post your codes though, even if you think they are un-related some of the experts on here can figure stuff through seemingly un-related codes and give you good advice.

Good luck

This is happening to my 96 max right now. I have yet to find a answer to the problem and it bugs me. It started after NOT putting NGK spark plugs so the coil pack suggestion seems reasonable. I shall subscribe to this thread and hope there is an answer.

Edit: How do I check the coil pack to see if it is going bad? I had to replace one before (I broke it in half taking it out) and that ***** was expensive.

I had the same problem. It was a vacuum leak I changed all my vacuum hoses for under 10 bucks. So I did and it worked. Try it its not expensive

U can ohm test it per FSM.

Its hard to diagnose if its jus starting to fail vs completely failed. All u do it disconnect a coil pack, judge engine resonse, plug it back in, move on to the next coilpack. If the coilpack is working properly, each time u unplug it the engine will stumble.

Clean MAF and TB per how tos. Check IACV. Test coils. Throw some chevron techron in the fuel tank

I am leaning towards this. Any good leads for parts?

Sounds like some other folks are also having this issue so let me try to be a bit more descriptive, should it help anyone. I've been paying more attention to when it happens and if there's a pattern.

1) The hesitation/jerk only happens when completely stopped (hold brakes) AND in Drive
2) It goes away the moment I put it in Neutral, back again once I put it Drive
3) It goes away if I add even the slightest throttle be it while holding down the brakes or moving slowly.
4) It happens randomly, but I do notice that it is more likely to happen after driving for an extensive period of time.

I put in Walker O2 sensors about 60K.

My codes are P0400 & P0325 (over 2 years now)

Its a coil pack on the way out as njmaxseltd stated previously. If you want to find which one it is and this is what I do myself, place the car in D and pull up your e-brake. If your e-brake is not working, you would have to have someone in there pressing the brake while you open the hood and disconnect each one by one. The engine will shake but you are going to leave it disconnected for a few seconds to ensure that there is not also a jerk with the shaking.

i would check my iacv if i was you

does it only happen at operating temp?

it could be that when your fan kicks on the iacv is dirty and takes a while for your engine to catch up (for an ecu "a while" is milliseconds)

this could be what your felling and cleaning the iacv is good preventative maintenance

im not outruling the coil pack though i just never had one go bad on me so i couldnt give you the symptoms

i had this rough idle and misfire audible through tailpipe but no codes. changed out bosch sparkplugs to ngk and all is good..just a thought

Well hallelujah. I just got a new code (P0305) and I think is directly related to the hesitation I am experiencing. I believe P0305 is the coil on cylinder #5 (right?). Is #5 the 'left' or 'right' bank?

Ok, anyone have a good source for part? Anyone bought from Amazon or RockAuto? Are the sellers/parts there reliable?

3 CEL Codes
P0400
P0325
P0305

Can someone confirm if cyclinder #5 is the 'left' or 'right' bank??

BTW, local Autozone wants $70-75 but amazon goes for $30.. Any suggestions on where to buy?

oreily's or advance--get the BWD brand. Autozone coils suck ***

cyl 5--firewall side, far right

http://forums.maxima.org/4th-generat...-sequence.html

Local Advance Auto carry BWD but $75 for left bacnk and 95 for right bank!.. ouch. That's a bit steep. Think I may try out a generic one for $30. Thanks for the feedback.

Same problem and just recently fixed. Either o2 sensor or coil, guaranteed. Except that my check engine light read cylinder 5 misfire and it was coil.

ohm out ur fuel injectors as well...just in case

Ill shed light on something no one has said yet. i had this issue two years ago. turned out to be coolant leaking from water outlet into my alternator. same issues. even had the abs light flassing intermitt. Check the neck to make sure its good and dry and go from there..

Since I’m getting P0305 (cylinder #5 misfire) intermittently, it is safe to assume the coil pack on cylinder #5 is probably going out on me.

BTW, I just received my coil pack bought from eBay for $30 shipped and I must say it looks and feels like a quality part. I’ve had my share of knock off stuff and I would say this is good stuff. Nice weight, solid feel, and very good overall finish. But then again, this is just initial impression so will have to see. Will install tomorrow and let you all know.

Thanks.

It turned out to be a spark plug

Situations like this...first clean TB & Maf. Check coils, plugs, and injectors.

It started for ME after my alternator was replaced along with the alternator belt, power steering was left as is.

The IDLER pulley, which runs most of the systems on the car, was adjusted the best we could by hand/wrench. The belt tensioner was tighten too much and it caused an ear piercing screech when the car first starts. I went back in and backed off the tensioner some and the sound went away.

My hunch is this hesitation/jerking while the transmission is engaged is related to the pulley/belt or something in that area. The reason I related the two items is because when I turn on the front window defroster then the bucking happens much more rapidly and more often.

When it's very very cold outside then the bucking happens more.
When it rains out the bucking happens a lot more.
If it's hot outside the bucking is not so bad, or if I drive for a while it's not that bad.

Is it possible that the idler pulley isn't adjusted tight enough, or the tensioner isn't adjusted right, and the belt is somehow slipping? If I'm turning the wheel while driving slow around a turn (like a highway on ramp) the car also seems to have the same symptoms as when stopped at a red light...

I'm trying to figure this thing out by guessing while driving and researching at night. It's really annoying and I'm going to try the things mentioned below in this post... but I just wanted to add my description to the mix.

Thanks for reading all that, good night

No more hesitation/jerk! It is indeed coil pack on cyclinder#5 -P0305 duh.

For people out there having coil pack issues, I HIGHLY HIGHLY recommend eBay seller ufititauto! The coil packs are of FNATASTIC quality, dare I say OEM. His posting does have product origin as Japan but I was doubtful until I got a hold of the item. Scoop them up before he runs out (only a few left). Exact match in fitment and quality in every sense and only $30 shipped. Advance Auto wants $95+ tax… Can’t beat that! Now, maybe I’ll get off my lazy **** and fix the other two CELs (prob not, even though I’ve had the seals/gastkets to fix them for over a year now)

Link to the item:
http://cgi.ebay.com/ebaymotors/ws/eB...OU%3AUS%3A1123


Images of new vs old coil pack:

I have exact same symptoms with no codes. Have had previous P0303 code and replaced #3 cylinder coil but not associated with this issue. This "bump" feel shows no relation to engine speed or rpm, only occurs during idle at stop in drive.

I had a p0303 just the other day and I knew it wasn't my ignition coil or fuel injector or spark plugs but it was the crankshaft position sensor the one that is on the transmission. It tells the ecu which cylinders to fire at which time. The code has not comeback and the car now runs at full power like new.

Always listen to njmaxelted, he knows his stuff. Post your other codes and get them fixed. Sometimes bad coil packs do not throw codes. Pick up some spares for cheap at a junkyard.... they go out... and only run NGK plugs.