Inconsistent misfire

[Darrinswait]

2000 I30t The car just developed a misfire a few days ago. But the next day, it was gone...for most of the day. The next day it ran great all day long. The next, it started out bad, but got better. I took it to the parts store and had the codes read. There were 19 of them! It'/s not as bad as it sounds though because i've jumped around part of the ECM becau part of it burned up. THe car runs fine with the ECM this way, until last week. I had codes that said catalytic converter needs replaced and O2 sensors need replaced. These have been consistent for a year or so, but as I said, the car has ran fine.

But this new problem I cannot figure out because it was inconsistent. I disconnected the battery to see if this would clear anything and it didn't, as expected so I went to buy a coil for the #1 Cylinder (code). When I started the car to come back home, it ran great and did for the rest of the day! Today, it is running awful again, as if one cylinder is misfiring again.

Should I be looking T a coil, a sensor of somekind, or something as simple as a spark plug or injector? I could really use some help here!

[jltibbs]

2000-2001 Maxima/I30 already had various misfire issues due to poor coils. If one goes, you might as well replace them all. I only found this out by talkin to Nissan. It may also behoove you to pick up an ECM from a salvage yard. Start there, then move to the coil packs.

Welcome to NICOclub.

[Darrinswait]

So you seem to be saying that you think the coils are the problem. Is it normal for them to be so inconsistent, or do they just either work or not? I do plan on getting an ecm soon, but I know that this is not the reason for the cylinder misfire. Please pardon any unintended incorrect spelling...this dang ipad...

[jltibbs]

The parts guy that I always deal with at my local Nissan says that if one fails it can cause issues with the others. That's why Nissan will always recommend replacing all of them at once. I'm also guessing that the ECM being burned up cannot be playing a positive role. The reason I mentioned going with that first is because replacing all six coils will set you back about $300. An ECM can be picked up for about $20-$30.

[Darrinswait]

Where do you find ECM's that cheap? I'll probably go with the "pay as you go" plan of changing coils as they fail, but again, wondering if a coil would be inconsistent as this has been. Have you heard of coils behaving this way?

[jltibbs]

Go to a pull-a-part salvage yard. They're cheap there. I have seen this, but it's only in the 00-01 Maxima/I30. They were extremely problematic.

[tigersharkdude]

99's also had this problem.

OEM coils or bust. Aftermarket coils (BWD, etc) will throw a P1320 code

[Darrinswait]

Started it this morning, it ran awful. Removed number 1 coil, checked plug, and it looked okay. Put it back together, started it and still ran bad. Decided to go buy coil, but first I disconnected ground cable. Went to get coil, car ran perfect. Stopped at a garage to talk to a mechanic who scanned the codes, nothing wrong, running smooth. Did not buy coil. Grrrr.....this car is maddening.

[tigersharkdude]

a lot of times a bad coil will not set off the CEL. The problem will be back, just remember OEM coils or bust. Non OEM coils will set off a P1320 CEL as soon as you start the car

[jltibbs]

That's the thing though, Brad, he's not throwing a CEL for that. Need to replace that ECM first. Eliminate that from the equation since it is known that it's damaged.

[Darrinswait]

I'll go to the pick and pull here in KC and see what they have, since that will be less $$ than the coil. Won't be able to go until next week though. I'll get back with you and let you know what happens. Thanks for all the help. By the way, just took the wife to a movie, and it ran perfect the entire time.

[tigersharkdude]

sporadic-ness...............sounds to me like a faulty coil. Thats just from my personal experience

You say you had 19 codes. Did you check the codes again after replacing the coil?

[Darrinswait]

Never did replace the coil. Can't get myself to spend the money if it's gonna run okay part of the time, but you said it...sporadic-ness. I think I don't have an Infiniti I30, but instead a 2000 Infiniti Dilemma. Gonna get a used ECM in a few days and see what happens then since the one I have has been "compromised."

[NutriaforBreakfast]

You could use a multimeter to check the resistance and other readings on each of the coils
The floor shop manual can tell you how

I would recommend doing 2 checks; one when the coils are hot and one when
the coils are cold

I have noticed emmissions problems usually occur when there is low speed missing
not the coils on my 1998