hey, i just got a 90 300zx NA after looking for several months. it's in great condition mechanically and visually, but i can tell its going to be an electrical nightmare. my problem i need solved first is with the coil pack on either cylinder 5 or 6 (its the one if you're in front of your car facing it, the left cylinder under the balance tube). I got it burned out, i figured it was a simple replacement part. I got it today, put it in today, and man, did that kitty purr! was almost like i had boosted the car compared to before (wasnt firing at all). So all was good for about 3-5 minutes, then it sounded like it did before-throaty and almost mustang like. thinking some other coil pack went out, i pulled over cursing, and found it was the same coilpack. now im really mad, because i just blew $82+shipping.

so my cylinder 5 or 6 coilpack burned out at least twice now. obviously an electrical problem, so i took out a multimeter and the only thing i could tell without any knowledge of what's going on, is that the resistance between contacts 1 and 3 NOT on the coil read about 17 ohms, while all the others read about .5 mega ohms. obviously there is too much current getting to this pack, but i have no idea where to start. i need help. im sorry if this is covered already, i tried looking, and no dice. and im sorry if this doesnt meet forum rules, i work full time and go to school full time, so the fact that i even got the coil in today between the two is a miracle, let alone that i got my meter out in the dark. any and all help will be greatly appreciated. thanks in advance!

 

I cant really help out that problem. But you can get coil packs on ebay for 50 bucks and under. Theyre used, but it beats paying for a new one. Yo ucan get singles pretty cheap to, just something to think about it.

 

hmm i hadnt thought about looking on ebay, but thanks for the heads up. either way, im taking her to nissan today during lunch to see what they say about it, so we'll see what happens

 

More likely to be your PTU then. Do you have a series 1 or 2 fitted?

 

i have no idea which power transfer unit i have, nor where to look to find out, but i did just see there's a recall out for american z's. i'll ask the dealership today when i take it there. The furthest back i can trace the lines is from the cylinder, around to the front to another harness which then gets all wrapped up in electrical tape, and then goes around and does stuff and i think goes into the engine. im probably wrong, but again, it was dark last night and i couldnt see well. but im definitely going to ask about that recall when i get over there today.

but quick question, would a faulty ptu cause the coil to be blasted with too much power? i figured it would just stop sending the signal or send it at the wrong time or something. im really uneducated when it comes to little self contained units on cars

 

Quite possibly. If the output stage was to stay turned on slightly (some sort of leakage) it could lead to a coil burning out

 

hmm ok. something to add to the issue, when i replaced it, the car was amazing for about 3-5 minutes. however, during that time, the car felt like it was misfiring or backfiring (more likely misfiring) not quite when cruising, but not quite on it. if you were cruising, it would stop misfiring/backfiring. does this sound like further proof of a faulty ptu or just the coil getting ready to fail or some other worse problem?

 

It is possible to have a weak spark caused by a faulty output stage. Whether it fires or not would depend on load, mixture, etc

 

very good then. thanks for your input, and i'll keep you posted after i hear what the dealership has to say about the issue.

 

Cool - good luck

 

You must use plantinum spark plugs in most any coil on wire engine. The VG30DE is one of those. The prior owner (or you) may have cheaper spark plugs in there. Replace all six spark plugs first with the proper ones. Then go about replacing the coil packs.

Can you possibly use the coils from the mid 90's Maxima? You might find one of those cars in a wrecking yard more often than a Z32.

 

yeah, i replaced all the plugs with ngk platinums and found a hodgepodge of different kinds of other platinum tips in there now. that really shouldnt have caused a coil to burn though, especially in 3 minutes.

 

Well anyway, I dropped the car off at the dealership yesterday, waiting for the diagnosis to come today. I also called nissan to check for any recalls on the vehicle, and they had to go through their archives to check out what this car has in terms of active/completed recalls. I'm hoping its the ptu and that it's covered by the recall. *fingers crossed* pray with me hahaha

 

If it under a recall, tell them you know of another guy that missed the recall and they should ship one to NZ for me

 

hahaha i woulda tried to pull some shenanigans, but alas, there are no recalls on my car. the dude at the dealership who was supposed to diagnose my car today ended up in an accident of some sort and was out today, so the dealership still has my car. and my racquetball equipment so i couldnt play today...my mistake but i was bummed. anyway, no recalls and no diagnosis as yet, so we'll see what happens.

 

you should call up nissan with your vin and ask them. someone at some main office.

a dealership tried to dick me once in my old z for a fuel injector recall and give me a 2000 dollar bill. i was like, "no, this ***** recalled" and after like a half hour they were like "ohhh ok, yeah youre right".

I also dont think there were certain vins that were recalled, I think they all were. Its easy to see it, the og ptu is black the newer one is goldish in color.

 

http://t1.gstatic.com/images?q=tbn:z...m/used/ptu.jpg

thats the **** one

 

hmm, so after a little more poking around, what you said seems right. all series 1 ptu's (pre 93 cars) were recalled in the US. what's interesting is that nissan said there are and never were any recalls for my car. i'm going to have to talk to the dealership and figure this out. but first, im going to wait and see what the actual problem is.

also, whats this about your injectors? im pretty sure i have the old sh*tty ones that corrode and fail. are those covered under a recall? i'd prolly get bigger ones if they ever decided to fail because i want to make my car turbo EVENTUALLY (save like 10 grand first which is a couple years because of school and now the car haha) but if i can get new ones for free for now, id be all over that.

 

No, the injectors were for my 85 and 86.

Theyre not THAT hard to change though. Check the ohms, they should be between 11/12-14? Look it up to be sure.

But if you plan on making your car turbo, youd have a motor out of a car to work on anyway. You can make it turbo, but its better in the long run just to get a clip.

 

Any progress yet?

 

OK so...here's the sh*t thats going on. i took my z that thusday to the dealership. next tuesday they finally look at it and tell me they have never seen this problem before, they spend the next few days doing SOMETHING (not sure what) but eventually they say they called nissan and nissan recommended they change the wiring harness. wednesday im told a quote would be somewhere around 2600 dollars for parts +15 hours labor. i laugh at the sales wench, and tell her i want to get my car, but she offers to try and sell the car for me, and im not too thrilled about. she says she'll put the actual quote together and let me know. friday i call back, and i dont think she has put the quote together yet, because she cant tell me how much its going to cost. i say i just want my car back at this point. they charge me 227 dollars and i get my keys. i go outside, turn the key, nothing. they drained the battery. she claims it tested low and i probably need a new one. (im highly skeptical of this, i hadnt had and still havent had any problem starting the car (not even a slow start)). so they come and give me a jump, but when the hood is popped, i notice my burned coilpack isnt in there (not a huge deal itself) but the bracket to mount it to my engine is attached. Then i notice that the adjacent coilpack is missing its bolts. then i get home, i see the balance tube is missing 2 bolts. I stopped by today to get my bolts back (i was driving another car bc my z hasn't passed inspection yet) and when i get home now, they dont fit. then i notice that a fuel line is missing one of its bolts and the other is barely even threaded. now i need to go blow another lunch break to drive over there and get more of the wrong ****. Naturally im super f*ck*ng pissed right now. i could have saved 200+ bucks and 2 weekends if i hadnt wasted my time taking it to them. the fact that they didnt even put my car back together completely is insulting. they didnt even try! i wrote a really angry letter to nissan usa, but i dont know that they'll even read it. what else can i do to exact my revenge while waiting for my harness to arrive (btw they wanted to sell me 3 or 4 harness and an ecm. they told me the ECM was blown and needed a new one, to which i declare shenanigans because the car still runs and there aren't lights flashing everywhere in the dash! they also wanted to sell me a transmission harness! wtf!!)

</rant>

sigh...im really mad at that dealership, and i'll never be taking my car back there ever. EVER.

 

I could of told you something similar to that would happen taking your car to the stealership..... Just bc the sign says nissan, doesn't mean the Jo Schmoe's there know anything about the Z. But don't feel bad, I had similar incidents with a local dealership here about 4 years ago with a timing belt job when I was just quite frankly to busy to do it myself at that point in time.

 

before I knew anything about these cars, mine sat a dealership for three weeks because it kept flooding.

they couldnt tell me that the plugs were wrong. something as simple as that. and they took the plugs out to check them.

the dealership is the worst place you can bring it. the mechanics there arent trained to work on these cars. im sure they can rebuild a sentra in a few minutes, but not a Z.

 

and i just remembered, when i had that fuel injector recall done on the 86, i was missing parts as well. idiots.

 

Yea and what really got to me was when I there trying to get my parts back, some older dude came in and said he took it to a private mechanic and he said his engine mount might be cracked, but the little greasy douche service rep guy asked him if it was making a clunking sound, and the guy said no more of a squeaking, and the service rep a$$wipe said that's proably not the motor mount, maybe your mechanic needs to go back to school. I just wanted to be like F*CK YOU dude, your mechanics can't even isolate an electrical problem and on TOP of that can't put the flippin thing back together! But I digress. This weekend I'm going to go to the library and see if they have the uber repair manual and check every electrical thing I can.

Also, I do have the series 2 ptu, replaced in 97. And does anyone know a reputable Z mechanic in the new york/nj area?