cooch85

I am a proud owner of a 1986 Nissan 300ZX. My car was sold to me by my Uncle Joe, who bought it at a dealer in South Carolina. The car has 120,xxx miles on its 3000 (non turbo) SOHC V6. EVERY piece of electronics on the car works, until last week, the fuel gauge still works but the actual gallon reading went out for some reason. Now, other then that this is a great car. My DREAM car, which is why Uncle Joe got the car in the first place.
So here is the dilemma I have had. The car sometime will not start. But most times, it will fire right up and run good for anywhere from 10 minutes to an hour give or take. But, ONCE the car does stall out, which it has done since the day I got it, it wont start. The fuel pump runs, the car cranks over good and strong but it doesnt even try to fire. Im thinking i lose spark. So after being certain the stock security isnt acting up, Im left thinking about the ignition system. Which I put a new voltage multiplier, new coil, new cap & rotor...I even put a new alternator on the car. Thought I had it licked, until the same old thing happened. Ive been told to check my "Crank Angle Sensor CAS" but I dont know. Please if anyone knows anything about my issue I could really use the help! This car has NEVER seen salt, or snow. And even though I live in Michigan, the car is my nice day car. When you see the pics you will see. Any thoughts on this would be appreciated. I hope this site is more helpful then the other Z club I joined.... Thanks in advance fellow Z lovers!

rogerz

for a start you got most of the info but analog or digital dash? I'm thinking digital since the analog only has a needle. if the five gallon low level doesn't come on you probably need a new sender. had to replace mine about two years ago. Courtesy nissan used to have them you could try them on that. Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen. Usually on a rainy night around Oh Dark Thirty. seems simple but I am constantly amazed at the people who don't get the battery system, working properly. what the hell is a voltage multiplier??


Clean the connectors for the maf, ecu and tps. Deoxit by CAIG is probably the best connector cleaner on the market. spray with CorrosionX after cleaning and before putting together this will help prevent any further corrosion. DON'T USE DIELECTRIC GREASE. may not fix the problem but will hopefully prevent other things from going wrong.

get some more data if you want help. fuel pressure. vacuum and check for vacuum leaks. I'd guess your problem is electrical so get the battery and cables in grade A shape. don't guess test things. hopefully uncle Joe changed filters and fluids on a regular basis.

cooch85

Hey Sir, thank you for the tips. I dont know a whole lot about these cars. Im sorry if I sounded ignorant. Uncle Joe is not around for me to ask what the voltage thing is. Sorry. But I can tell you where and what its hooked up to. It is plugged into a few wires that come out of the fender wall. they plug into this part I thought I was told was a voltage multiplier or something? then from that whatever it is...there is a going down to the coil. The word PUSH on the connection. So I am not even sure what it is.
Now as for the battery, it has the correct terminals on it. Someone had put a cheapo ground terminal on it, but I work as a towing operator and pulled a ground terminal off a nissan sentra or something like that so it matched the power. The ground wire itself is stock. I know there is a strange bare section of wire the is like 8 inches from the end that connects to the battery, that has a connection that grounds the body out, but ive never checked to see if it only grounds at the starter or is it also grounds to the frame.
As for Uncle Joe, I cant ask him what he did...But I am really trying to gather as much intelligence on this car as I can. I would even pay for help at this point. So I would consider giving you my number, if you would be interested in giving me some help. I would of course need your number. And I tried to post some pics to the forum, and didnt have much success. But I have videos on my phone of the car running and not running, all kinds of in depth pictures. If youre not interested I thank you for the help you have given. It is appreciated. Thanks
Oh, yeah digital dash.

rogerz

ground to the frame. grounding thru the bell housing isn't reliable. on the original cables there was a square copper piece crimped to the ground cable which was bolted to the frame with an M8 bolt outboard and little below the m6 bolt that holds the battery hold down bar. What you are calling the voltage multiplier (for god only knows what reason) most likely the igniter. A power transistor that acts like points did in antique systems. make break power to the coil which is what generates the high voltage needed for the plugs when the magnetic field collapses.
download the fsm from xenonzcar.com all the answers are contained therein if only the pilgrims would read it.

you can't just take a terminal off you need the whole wire with sealed lead terminal crimped and attached. anything else you attract corrosion. instead of robbing junk go to a real battery shop (ie not WalMart) and make up a set. I got my 86 done for under 20 bucks. go cheap on battery and cables and that 86 will always give you headaches.

I got plenty pics of my 86, 86, 85.

cooch85

Ok Sir. First of all, I would like to thank you for your help and ideas again. That voltage whatever, now i know it is called an igniter...i referred to it as whatever because that was what my uncle had said it was. But hes been gone for a while now and I cant very well ask him. I did download the FSM the day I joined this forum. I dont know what you mean by pilgrims....Im doing the best I can to try and figure this stuff out though. I dont need someone to belittle me or make me feel ignorant for not knowing the name of a part, to a car which I have openly stated Im not familiar with. I am sure you have all kinds of pics of your cars. Sir, I meant if you could see what MY car looks like under the hood, you could have maybe seen anything that is not correct. That last Z forum I joined was full of ********. It was a joke, I thought I would try this one. I was relieved you had some suggestions for me...but I dont know if you are bothered by me or what. Just seems like you think I am an idiot and that is not something I do need. That being said, thanks for everything. Sorry for calling that part by the wrong name.

cooch85

So if anyone is still checking in on this post, my car has completely quit now. And I have downloaded the FSM, and printed most of the areas I needed to be able to read easily. So in anycase, I cleaned all the connections as I was advised to do. My battery has been load tested and all is good there. I have a brand new 1080c.a. battery which, not that the car will ever be driven in the winter, the battery makes 950 cold crank amps. I have not figured out how to do a fuel pressure check. I can kink the fuel line where it comes out of the filter, and feel pressure when the key is turned on the power is put to the system. So with that being said, I have had a few people tell me that their cars, with the same engine, had problems with the crank angle sensor going bad. From what I have read in the FSM it does seem like the ECCS requires 2 things before the engine will fire, a reading from the Crank Angle Sensor and a signal or reading from the Air Sensor. I have followed some advice from a person on this forum, but instead of the car having a problem where the ignition system would act up every now and again it has been dead for over a week now. The FSM mentions putting the ECCS into diagnostic mode, and also mentions which pins to check for voltage, which ones to check for ohms etc. But what I am wondering, is even if the circuit is good and all, but the actual sensor itself is bad is there a way of finding that out without just replacing the wire harness and what not? Appreciate any thoughts from anyone. Thanks guys