Sometimes when I stop at traffic lights the car seems to idle kinda rough. It seems like it misfires. It happens in 60% of all the time my car idles.

Five coils were replaced with gray-dot coils before I bough the car. The last coil was replaced one week ago. MAF, all spark plugs and fuel filter got 3k miles on them. Injectors were also professionally cleaned 3k miles ago.

It seems that everything that might cause the problem is in good condition. There also were no trouble codes for the last two months. What do you guys think could be the cause of this misfire? I don’t even know what else to check.

Thanks in advance.

 

get a tester. put the positive wire on positive terminal of the battery then touch
each spark plug with negative. The motor will sound as if its about to shut off on the location of misfire. And you could always try an OBD II scanner if you have a
check engine light

 

do you know what type of plugs were used?

 

yap, original platinum spark plugs.

I'll have to take out each coil in order to reach the spark plugs. Won't taking out the coils kill the whole purpose of this procedure?

I got a SES light two months ago, the cause was a misfire in the 5th cylinder. I took out that last "original" coil and put in the new "gray dot" coil. The engine was certainly running better but it didn't fix the misfire at idle.

 

i have the same problem on cylinder #2. it really really sucks and i've done everything that he has.

 

test each coil and check your plugs. for instructions on how to check them pm me

 

how many miles is on your car? Why dont you just do a tune up, change all the spark plugs to either NGK Iridium or dbl platinum.

 

Try testing the harness plug to the coil and the coil's continuity.

 

I heard 2k maximas have a TSB for EGI harness...those lead to misfiring...check it out on studman's website

 

It was done 3k miles ago. (as I've said in the first post )

Any ideas what else could be faulty? (my first post lists what I have already replaced)

 

Thanks for your info guys, I'll definitely check it out. Sounds like it could be the cause.

 

make sure the injector harness doesnt have any damage in it. I had one of my cylinders misfile a while ago and i found a wire was chewed through...
Now I have a similar problem but this time its not isolated to one cylinder;...

 

ok, checked everything you guys suggested but all this stuff seems to be fine.

Could dirty throttle body cause this? It happens only while the engine idles.

 

Mine's doing the same. Any codes on yours? I'll have mine pulled in an hour.

Maybe o2? I think I have mine narrowed down: Injectors, o2 or pre-cat. Plugs are stockers with 30k on them. I'll check that this weekend too.

 

nah, no code (that's the third time I'm posting it in this thread )

How can precats or o2 sensors cause this?

 

any resolution to this???
It appears I am having the same problem with my #6 Cyl.
http://forums.maxima.org/showthread.php?t=453113

 

I remember a previous post of yours having a bad cat smell and no code...
I'm going to say the two problems are PROBABLY related and it's an A/F problem for some reason your 02 hasn't picked it up.
(maybe it's weak or when it adjusts A/F the problem goes away).. There are so many possibilities...
We know that it's an intermittent misfire (from your first post) and probably just hasn't happened enough times in a row to pop a code.
I would put it on a scanner. I'm willing to bet there is a stored code that hasn't popped the light.

 

I'll probably take it to my mechanic next saturday. He has one of those scanners that can display currant time readings.

 

time readings?

 

well, I mean their scanner can display readings of all sensors at present time, not only check for trouble codes.

 

good idea, maybe ill need to do that too when I run out of ideas... good luck

 

I can do that with my OBDII reader, I just don't know what to look for???

 

Cylinder misfire
What kind of scanner you using?

 

I don't know which one he uses, all he told me is that his "scanner can take present time readings."

 

I'm researching the laptop software ones right now.. Sometime in the next few weeks I'll take a few snap shots of the read outs and post them up here. They are around $200.00 for the software and hardware. (well worth it, IMO)

 

http://www.myscantool.com/
this is the one I am using

 

I seen that one for sale.. I'm kinda leary about it as compared to a few other ones that cost about $50.00 more..Sine the proscan one is a single person operation and not a big business. (One guy created the software and is just marketing it online) I read on his feedback where a whole bunch of people got a bad batch of CD's and he took forever to send them another one and didn't even offer a software download online to keep himself protected from piracy.
Any problems with it???
How is the accuracy of the dyno/test runs????? any snap shots you could provide??
I read somewhere that it takes a reading from the ECU every 100 milliseconds or so and draws a wave form from reading to reading, thus having the ability to be able to miss intermittent problems??
Any info you have on the product is great..
Sorry for hijacking.

 

no problem, It's a really good program so far, but have not utilized all of it's abilities so far.
And yes he is a bit slow on the troubleshooting issues, but he has helped after a little time.

 

Hello,
My name is David Gore, and I developed the ProScan OBD-II software (www.MyScanTool.com) currently being discussed here. I check my server logs daily to keep up with where my traffic comes from, and that is how I found this thread. I'd just like to take a moment and clear up any confusion that readers may have.

I'm a computer engineer and a car lover. I developed the ProScan software several years ago after spending $550 on a programmer for my custom Camaro, and then I needed an OBD-II scan tool, which was going to cost about $300 more. So I set out on a mission to develop my own inexpensive scan tool. The software I developed actually turned out quite nice and a lot of people were interested in using it. So I set up a web site and started selling it. At first, it was just me. However, over the years the demand has increased and we now have several people involved. We strive to keep our business as small as possible, however, as that allows us to keep our prices as low as possible.... currently the lowest-priced scan tool in its category!

I'm assuming that you are referring to our eBay feedback. We did have a bad batch of CDs, but we did send out new CDs immediately after discovering the problem. However, our ProScan software is always available for download from our web site. So the statement about us not offering software downloads is not true, just see our web site. So everyone that did receive a bad CD could have downloaded the software immediately.

We sell over 100 ProScan kits on eBay every month, but only a very small percentage of buyers leave feedback for us. However, we have a feedback score of over 2000 and a positive feedback rating of 97%. Some people are just impossible to please. If every customer would leave feedback, our score would be 99.99% positive, but unfortunately that isn't the case. However, our score still speaks for itself.

We also offer a 30-day money-back guarantee. If you aren't satisfied with ProScan for ANY reason, simply return it to us for a full refund. We guarantee that you will love ProScan, or you will get your money back. We are that confident with our product.

The dyno feature is based upon acceleration and weight, and uses the same algorithms as in other scan tools and even in the expensive G-Tech tools. Acceleration-based dynos are not as consistent as chassis-based dynos, but if you take a scientific approach, the information obtained is very useful. This is a common question, and I have addressed it in detail in our list of Frequently Asked Questions. So for more details on this, see www.MyScanTool.com/faq.html

All OBD-II scan tools plot sensor data based upon "sampling" the live sensor data. The sample rate depends on your vehicle's OBD-II protocol and the hardware being used. ProScan allows you to tweak the hardware interfaces timing to get the fastest sampling rate available for your vehicle.

If you have any more questions or comments, please let me know.

Oh, and if you guys want to order based upon this thread, just include "maxima rebate" in the note section of your payment, and I'll refund $5 from your order!

Thanks,
David Gore
Owner, Gore Research
Developer of ProScan OBD-II Software
http://www.MyScanTool.com

 

Thanks, I'm glad that you are finding ProScan useful. I also apologize for any delays associated with responding to your inquiry.

If you have a common question, one of our support representatives should be able to answer your question within 24 hours. However, if the problem is very technical it will get forwarded to me, and it may take me a day or two to respond as I'm usually tied down with software development.

Thanks,
David Gore
Owner, Gore Research
Developer of ProScan OBD-II Scan Tool Software
http://www.MyScanTool.com

 

Hello ProScan, thank you for whoring up my thread. You could have just PMed those guys. If the reason of two previous threads was adverting you could have posted it in the specific section, dedicated to it.

 

I'm sorry if you were offended by my response, but I was not the one that switched the subject from your problem to my scan tool. Questions were being asked about my scan tool, and I simply wanted to answer those questions. The comments made about my scan tool were based upon assumption and were misleading, and I simply wanted to make sure that everyone who read those comments would also read my response. It is only fair.

If the original post referencing my product is removed, then I will be more than happy to remove my responses to that post. I'm a nice guy, not a spammer.

Again, I apologize.

For those of you reading this, please respect DrKlop's wishes and do not reference ProScan in any future response to this thread. If you have any additional questions or comments regarding ProScan, just PM me or see our web site (www.MyScanTool.com).

 

ProScan, I've sent you a message via your website since your PM does not work.

 

that was me...
I should receive a hijaker of the month award or something....
yea, after reviewing your feedback again I saw where 1 guy was having a problem downloading...
lol...my fault.....
hijack off....
DrKlop: I'm not positive about the Autozone scanners, but IIRC they also pulled dtcs (stored codes). IIRC, they tell you nothing will come up unless there is a light, but stored codes still come up, someone else can chime in
You could go there and tell them that it was on just a second ago, it must have just shut off and see if anything pops up.

 

Would this software work with an OBD plug/wire that works in an Audi?

 

I would like to remind everyone that I'm still looking for help. The problem still exists, AutoZone code reader does not show any trouble codes. This is my original post:
Any help is appreciated.