I drive 1999 Maxima with 95,000 miles on it. Few years back my car started having problems in the winter time regarding the idle and during acceleration. The idle would start at 700 rpm and drop a few hundred to 500 or so and go back up. However, the acceleration during this would be jumpy and if gassed hard enough, the engine light would come on. Took the car then to ETD and spark plugs and various other things were replaced but to no avail. By then, spring came around and the problem dissappeared. Its back now again for the third straight year now and I have yet to figure out whats causing it. Variety of ideas have come to me such as the throttle body needing cleaning, the knock sensor needing to be replaced or if there is a gap in my exhaust system causing oxygen to mix in. What throws me off is the fact that the problem only exists in winter(cold weather, I live in NJ) and no other time. Please advise since I love my car and it feels like Dr. Jekyll and Mr. Hyde regarding the change in personality!

 

You might have a weak coil pack.

 

Regarding the weak coil pack, what do i need to do then? Im not too familiar with all the engine components. (I should be go to hell for being a car enthusiast all the while)

 

Coil packs are the long black tubes that go on top of the spark plugs. Try disconnecting them one at a time, with the engine running. If a coil pack doesn't make the car run ROUGHER then it's bad...

 

I dont think I will be able to tell the difference while in park and with the engine running. I can feel and notice it while driving.....How am I going to know whether the car is running rougher or not...What do you mean its bad?

 

If you do what I told you'll know what I mean. The car will be running rough, only on 5 cylinders, sort of like spuddering...

 

This type of problem could potentially only exist in the Winter time ?

 

I know what you mean. Going through the same pains right now.

3 days ago, running fine/great. Ran fine until I parked it in a driveway. Turned off. Went inside. came back out, 30 mins later, started it, and it runs like poo. This was at night by the way. I live in the desert (west texas), and it takes longer to get cold during the winter months than lets say, NY...or somewhere north.

I got a CEL, saying Cylinder Misfire #1. Replaced coil pack. No change in performance(idling, power). CEL goes away though.

Today, I replaced all six spark plugs. Problem doesn't completely cease, but it has improved. Rough idling and lack of power has gone down alot, but still feel some roughness in idling and power loss. No CEL.

My best guess at this point is some weak coil packs, and I don't have the money to go replacing all of them at this point. But am happy with this temporary "fix" for the time being. I've done some sound tests on the fuel injectors, and they all sound the same (same strength ticking). And since I've changed the spark plugs, and noticed a direct improvement, I'm betting this problem is due to spark in general.

So, if anyone has a best guess answer at the root of the problem, I'd appreciate it.

As for defsquad, Try changing your spark plugs again if you have the time(assuming you didn't already this winter). I paid about $13 for 6 (including tax) of them at checkers using the NGK coppers (BKR5e11), and it took me less than an hour to replace. I think if the coil packs are weak, then it would take less power to get a good spark on clean and new spark plugs...Versus having the coil pushing current through a plug that is colder (due to environment) coated with carbon and what not. Also to note: I replaced my spark plugs 6 months ago with NGK coppers, from Bosch platinums, and noticed no real difference...but then again this was during the warm months.

I have a 1995 Maxima with 225,000 miles.

-Wishing I had a d amn CEL or codes to help.

 

Quick note: even tho fresh spark plugs helped smooth out the roughness, I've found the culprit. A fuel injector took a **** on me. It's fuel injector #1 (yay, i have to take off the intake manifold). What's weird is that there is still no CEL after I replaced a coil pack (the old one read diff ohms than the rest).

I used the testing procedure recommended by DB Martin. Testing the gray wiring harness to the left of the engine: Male pins 1,2 (1) read 0 Ohms, while 1,5 (5) and 1,6 (3) read 10 ohms like the other fuel injectors (2,4,6).