'84 300ZX Ignition Problems

Hello. I have had a 1984 300ZX non-turbo for 2.5 years and have been having problems lately and now it has become so bad that I can't drive it. About a year ago I was driving to school in the morning and about 1.5 miles from my house my car died, no sputtering, nothing, it completely shut off and wouldn't start; it would crank over but not even try to start. I came back after school and it started and ran rough for a bit but then ran normal. It did this at intervals of about two weeks three times after that, always at the same distance from the house. After that the frequency increased so I took it to the dealership and they said they couldn't find anything wrong. I had a mechanic put in a new ignition switch and some fuel components to see if that pacified it but it didn't. I checked the relays, fuses, and fusible links but found nothing. I took it back to the dealership and they said that the distributor had weak resistance and the timing belt was loose. I recently put in a new timing belt and distributor but the problem persists, it will start fine most of the time and at random intervals it will just shut down. :banghead:
Any input would be greatly appreciated.

when the car dies do you loose all your lights as well? it sounds like a loose connection to me.. that's the only thing that could explain something like that happening... i'm assuming the mechanic ran an ecu diagnostic?

No I don't lose the lights and yes the dealership ran the ECU and said that the distributor had weak resistance.

change the distributor cap...its cheap, yours could have moisture in it that will cause rust which is not good for spark.

good luck!

MIKE JONES!!! MIKE JONES!!! :lol: sorry had to do it...can't listen to the radio with out hearing that name. MIKE JONES!!!

Umm......yeah I forgot to mention I already changed that too.

Tehee. That's cool.

hmm, try running another diagnostic now and see if she throws any codes at you, but it's gotta be a loose connection somewhere in order for it to die like that.... does it do it when the car is cold at all? or just once it's warmed up...

Ok I'll do that. Well it's been awhile since I've driven it but I don't think it ever did it when it was cold.

Well now that I think about it, it has died cold. After dying I would try starting it and after some time it would but I had to keep it above 4k to keep it running because, as I now know, the injectors would just keep pumping gas into the cylinders without a spark, so it would flood. So I had to keep it revved to clean out the cylinders. But sometimes, well most of the time, if I let off the gas and let it idle down past oh, about 2k, it would try to shut off like usual, but the if I revved it back up I could usually keep it running.

Another thing, probably doesn't help but: After awhile I started noticing that when it wouldn't start, I could hear a clicking sound coming from behind the passenger seat along the wall in front of the rear wheel-well. It would never start when I heard this but everytime I couldn't hear it it would start.

interesting, that's where the fuel pump relay is located...

Hmm....I'll have to check that out.....

I have this exact same problem on my '86 non-turbo. The only thing I've noticed other then what you have pointed out is that the sound is not actully coming from the back right side of the car. It is bouncing off of there, but is actully coming from a small fan next to the lights on the strip between the t-tops. Mine only buzzes when my car isn't going to start as well, but I can't figure out the connection that is has with the problem. Mine has failed to start cold, but seems to have more problems when it is warm. In fact it is basically undrivable in the summer. You're the only other person I've found with this problem so maybe between the two of us we can figure something out eh?

Wow, I thought I was the only one on earth and my Z was cursed! Anyway, now that you mention it, my car seems to fail more frequently in the summer too. I didn't drive it all this summer and I got it back from the shop about three weeks ago from getting the new timing belt and distributor installed. Other than a slight miss in the timing, it didn't give me any problems so I hoped and wished that I fixed it. I drove it about 300 miles before it shut down just like old times last weekend.
My Z doesn’t have T-tops and you said it was a buzzing sound you heard? My seems more like a metallic click like possibly a relay but I’m not sure what it is because I haven’t pulled off the panel to see if the noise is actually issuing from there. I’ll be home this weekend and I’ll check it out and tell you the dealio. Any other info you have could be helpful so feel free.
Also, if you have the time, check your ECCS or ECU whatever they call it on your year. The procedure is in any after-market manual and if you don’t have one, I recommend Haynes.

mrz64 that's the automatic climate control fan... it really shouldn't have anything to do with anything except your cooling and heating system... sounds kinda weird to me..

oh and for a manual, why pay $20 for a manual when there's one online for free!! :D

http://www.gowhatnot.com/nissan/frames/menu.htm

Yeah, all I know is that fan only comes on when my car isn't going to start. I had to borrow my brother's car to get home tonight becuase it wouldn't start, but I'll check the ecu first chance I get tomorrow. Also, thanks for the help. I too thought I was alone on this; I cant seem to find anything else about it anywhere.

yeah... well there has to be a logical explanation for it... you're saying the fan ONLY comes on when the car isn't going to start? and NEVER does when it will start fine?

could possibly be a crank postion sensor or the fuel pump relay.

Yes, it only comes on when the car is not going to start. If the car is going to start, it will never turn on. I do know that it's not a relay problem, but I'm starting to suspect that you're right about it having to do the ecu becuase the more I think about it, the more it makes sense.

Well, I looked for my fuel pump relay where someone said it was (passenger side in front of rear fender) and couldn't find it. But someone said earlier it could be the crank angle sensor; that's interesting because my ECU said that it was messed up. How do I get one of those? The only place I found was Nissan and they only sell it with the distributor which is $500. I already changed the distributor, I got an A-1 from O'reily and I don't think came with a sensor. Ideas??

well try the connections to the crank angle and the distributer since you said after the timinmg belt change it was fine for 300 miles and they may have nbeen bumped a little and held together slightly better causing it to run a little longer
try cleaning the connections and adding some dielectric grease and see what you get

good luck

Ok I'll try. Umm...do you know how to do that? I have to remove the distributor, right?

Hey does anyone know how I go about checking the connections to the crank angle sensor? I don't want to mess anything up because I hear that that sensor is pretty durn important. Thanks

It sounds like im having the same problem with my 84 300zxT. My car has run fine until recently. I would start it cold and it would idle fine, but when I drive it would lag and bog down if I accelerated too fast until it was warm. Then I would start it hot and I would have to keep it revved above 2K so it didnt die. Now it will not start at all but it turns over. I am getting fuel but no spark. any suggestions?

We have a 1984 Nissan 300 ZX with no spark. New ECU. Coil, Distributor and all associated hardware is new or good.
Turn on the ignition key and the ECU does not bulb test or give error codes unless you momentarily ground terminal 6 whereupon it will give codes (only AC errors) and then won't turn off when the switch is turned off. Dealer won't work on it and Nissan USA knows nothing and doesn't want to help.
Below is attempt to fix summary:
I will first list parts replaced:
ECM 3 times
LED assembly in the distributor
power transistor
cylinder head temp sender (from a trouble code)
coil
EFI relay
timing belt

Things done and checked:
Checked output from dist to ECM, got the 360 signal and 1 other signal (assuming #1 cyl) with a good oscilloscope.
power to + side of coil
power to ECM
All grounds I could find with help from Alldata and an 84 300zx troubleshooting disc.
Condenser between coil from and ground @ dist base

Engine cranks normally, no spark from coil secondary. Checked and found no pulse on - side of coil.
Ignition on, ECM would not boot even with power on the proper pin at the ECM, unless a momentary ground of the #6 red wire at the ECM, from the EFI relay. Once powered up, turned screw to get codes, got 2 relating to the A/C. However, when ignition switch off, the ECM stays powered up (checked for 15 minutes) until ECM physically unhooked from harnesses. I have contacted the local Nissan dealer, and they disavow any knowledge and desire to tackle this, so in my shop it still sits.
If anyone there has any ideas, information or experience with this type problem, I sure would be grateful for help."