Does anyone have a link to more information about how to check and replace the coil packs for our VQs?

I'm experiencing some misfiring problems under acceleration right around 4k RPM and I herd that the '99s are notorious for coil pack problems.

I just reached 100k miles, but this problem has been getting worse and worse, now i can hear a misfires anytime above 4k RPM, its really starting to bother me, and I'm not able to get the full power I should be from my VQ.

Any help would be greatly appreciated,

Thanks guys

 

you have to measure the 3 connectors with an ohmeter. if you give me your email, i can send scanned pages from my haynes manual if you dont have one already. if you do, it has intsructions their.

 

thanks digdug, has anyone else delt with this problem before?

bumpity bump

 

if in fact your coil packs are bad, fanaticrockford had some for sale for around $135 shipped.

 

The Wizard had coil pack probs on his '99. But they didn't rear their ugly heads until we installed his supercharger. Doing what we thought was just a shot in the dark at the time, we swapped in my '99 coil packs and his car ran great! Really weird that the problem only surfaced once he was boosted. Anyway, we tried the testing thing first but it is so difficult. Haynes has a different method from the FSM which as a different method from the Chiltons. We got nothing decisive trying any of the tests. We threw in mine and problem solved. He then ordered new ones and has been fine since. If you have another '99 friend, that would be your best bet. If not, I think you have to take the chance and order up, because the tests are too hard, at least in my experience.

http://www.garrands-nissan.com/New%20Website/parts.htm

 

I have the same problem.
Mine hesitates around that same rpm, and it is really annoying.
It is kind of a ghost problem though, because sometimes it does that and sometimes, it doesn't. I know that it is a cylinder misfire, because a code said that one time, but the code does not stay there all the time. It just comes and goes.
I am just waiting until I get some money to put the coil packs in there.
I think I will try getting two (one left bank and one right bank) and try swapping them in all the cylinders until I find out which one is causing the problems.
Hope that helps.

www.rockauto.com has them for like $50 or so.

 

Yeah... I've started having this problem recently, also... so much for downshifting... it's only getting worse...

 

I wasn't thinking. All 4th gen coil packs are the same part number so scratch what I said about a '99 friend and change that to any 4th gen friend.

 

So are the coils exactly the same....how come the myth is only in the 99s. I am now pondering on mine.

 

I wonder that too. They are the same part number. I double checked this with my OEM Nissan guy (link above). I don't know what to tell you. I thought it was a 'myth' too until it happened to Jim. All I can guess is that there is something about '99s that make the coil packs go bad. Does that make sense? It isn't the coil pack itself.

 

Here's my answer from a similiar thread from a few days ago.....


Don't waste your time. I had bad coils on my 99 max. I tested them 3 different ways using the methods described in Haynes, Chilton, and FSM. Passed some tests, failed others. Very inconclusive results. Based on recommendations of others, I bought new coilpacks. Before I installed them though, I ran the same tests on them. Guess what? Same crappy and inconclusive results as the bad ones. I installed the new coils, and BAM!, my hesitation issue was gone.

For more info, here was my thread from a month or so ago...
http://forums.maxima.org/showthread.php?t=393081

So, the question still stands.... what is it about 99's that cause the coilpacks to go bad?

 

Ahhh, it's driving me nuts. That method sure is inconclusive. Uhm, to you guys w/the same problem I'm having -- when you're feeling the hesitation, is your tachometer / RPM doing anything funny?

 

When I had my problem, my tach did not do anything wierd. What is yours doing?

 

Well, when I try to accelerate, the tach jumps up about 500RPMs, back down, then accelerates.

 

I believe the '99 have a different wiring setup than the rest of the 4th gens, i know this is especially true on the 99.5s and the SE-Limited trim, which i see most of the people who posted in this thread are.

thanks digdug, ptatohed, Brudaddy, Thahman, and Wizard
you guys were a big help.

I'm just goin to set some of my paycheck aside to deal with this problem and hopefully get rid of the misfires once and for all.

 

Wizard - I think the OEM spark plugs that came with our 99's are crap. So crappy, that they cause our coil packs to burn out. I recently completed my 60'000 mile service and found the plugs to be completely shot and defective. These plugs were the OEM NGK Nissan installs. If the plugs are faulty, they might cause the coil packs to burn out prematurely.

I'm sure there's a definate correlation between crappy plugs and failing coil packs. Some claim that Nissan put in poor-quality coils to begin with. My guess is that if we change our plugs every 30'000 miles, it might solve the failures with our coils.

Needless to say, my max is getting new plugs every two years or 30'000 miles. Period.

 

The NGK platinum plugs are the same for all 4th gens. They are good plugs.

 

Thahman,
That almost sounds like a loose belt. After installing a supercharger, there is always a little guesswork/expirimentation with the belt tension. During my first run out, I had what you mentioned. I would gas it, nothing would happen, my RPMs would go pretty high ... and then it caught and the car went. I tightened my belt and I have been fine. Not sure if that's your problem but at least check your belt tension.

 

I'm not sure but today I've noticed my tranny getting very loud.. when I engage the clutch, the more I let go of it and press on the gas, the more whinny is sounds. Not sure if this can have anything to do w/the RPMs jumping.. ahhh

 

Did you ever figure out your problem? Is it tranny related?