I'm new... Driving problems etc HELP!

[1973240]

so i recently aquired my first 240z after wanting one for a few years. it needs a little help but im baffled by a problem and its my first z so im unfamiliar with the car.

got the car home. its a 1973 240z. had to buy a distributor cap and plug wires (electronic ignition) to get it to fire and had to put the blk/yllw wire on the coil for it to run. the previous owner is deceased so i cant talk to him and ask what he did but he was messing with the wiring for sure.

i got it to run (suprisingly well) in the first two days but when i try to move it it dies. it idles excellent and revs up excellent in nutreul, and it moves fine while disengaging the clutch but once the clutch is fully disengaged it acts as if the key was immediatly turned off. it will idle down the road for a while if there is no throttle applied but as soon as throttle is applied it dies.

i cant help but assume its an electrical problem because the wiring was tampered with and in nutruel, it runs fantastic. doesnt even smoke once its warmed up.

the dome light, headlights, brake lights (not tail lights), backup lights, and hazards do not work as well. and the tach is pegged at 8k anytime the ignition is on run or start.

im stumped.

also there are two wires coming off the ignition harness that are not being used, a green and a black i believe, and i dont know what they are for.

anyways any help or advice would be great!!!

thanks guys

[1973240]

oh yes and also, sometimes it will idle for long periods of time no problem, and then occasionally it will just quit like it does when im trying to drive it, and it starts right back up and idles all day long again.

when trying to drive it if it starts to die and you put the clutch in it will stay running.

and sometimes if it moves with no throttle and doesnt die and you put the clutch in and stop it will finally die, but not everytime.

ive talked to many people and nobody has ever even heard of this.

weve made sure the fuel filter was clear too.

thanks again

[WingZr0]

Hi, welcome to the club . Pics would help us solve your problem. The lights sound like a electrical issue for sure but you engine problems sound more like a vacume problem to me. You have any missing, disconnected hoses or leaks?

[Z Tyler Z]

I could be completely wrong here but could it possibly be a timing issue? Maybe it's not advancing and that's why the car is dieing when you try and drive it but runs fine in neutral? I'm also pretty new to Zs, so I'd wait for some more experienced members to weigh in before you buy/attempt to fix anything.

As for the mystery wires I'd download a FSM and try and figure out what they are. Here's a site that you can download one from if you don't have a paper copy. http://www.xenons30.com/reference.html Black wire is a ground, not sure on the green wire though.

Welcome to the club, glad to see yet anther member from Washington has joined. Good luck with your Z, tons of information on this site.

[alhbln]

Could be several problems, lights not working and tach pegged at 8K is clearly wrong, so i would start checking the electrical circuits, then check the advance at idle with a strobe gun and then look for vacuum leaks. From what you describe, i would second Tyler, the timing may be too advanced or retared, probably because the distributor was not set with a timing light after installation. Have added a wiring diagram of the ignition which might be helpful.

Does the engine also die when you rev it without the clutch being engaged?

When the engine dies, does it switch of instantly or does it die within some seconds and maybe a bit of stumbling?

[EScanlon]

Hi, welcome to the club . Pics would help us solve your problem. The lights sound like a electrical issue for sure but you engine problems sound more like a vacume problem to me. You have any missing, disconnected hoses or leaks?

I concur with the welcome to the forum, but I have a question for Wingr0...

How do you expect the pictures to help? Or are you expecting a set of pictures that

a) show the car running.

show the car accelerating in neutral

c) show the car stopped after it stalls.

, just had to ask.

But I also consur that it sounds as though it's a timing/vacuum issue.

With all the changes that have gone on, the BASICS need to be checked. One of those sneaky little basic items is the Vacuum Advance Plate inside the distributor. It affects the timing via the vacuum.

Remove your distributor cover, and disconnect the vacuum advance hose and either with a bulb or a clean hose, suck on the hose to create vacuum and then release. Repeat several times emulating an engine accelerating and decelerating. The points plate should rotate and return FREELY. If it does not, that could be part of the problem.

Just a thought.

E

[WingZr0]

HAHA , nah, he mentioned wires disconnected that lead to now where. Figured we can see what wires they were, how bad the wiring is are spot if any vacuum hoses were routed wrong. Yeah, guess I layed the tracks for that one .

[Zforce]

Could be no damper oil in carbs too.

[1973240]

hi guys. wow i gave it two days not expecting a whole lot of feedback and im impressed by how much help i got right away .

ok an update, weve been trying to drive the car more to test more theories we had and it drives better but its still not really driving. sometimes i can get to about ten or so mph and shift into second before it tries to quit and also at this point i can continue driving it (i have a nice long driveway) without it totally dying it just stalls out or whatever you would call it but it will kick in again even if i dont move my foot from the gas pedal the whole time. it surely is strange. if youve ever shorted the coil or anything like that where you ground a wire and the engine starts to die but will stay running if you take the wire back off, it does that sorta thing. its very sporadic. anyway although it seems very much like a shortage somewhere i will search for vacuum leaks and such tomorrow and take some pictures. my auto tech teacher suggested a wiggle test of the harnesses on the torquing side of the motor but it didnt kill it in nutruel. however one time it died and wouldnt start back up until i wiggled the harness. so who knows. maybe wind draft or bumps are shorting a wire somewhere. anyways thanks all for the responses!!!

[1973240]

and as far as i know everything is hooked up right except those two stray wires. the black wire kills the engine when touched to the neg. of the coil and shows system voltage, the green shows nothing and doesnt do aything. i thought maybe the tach was put on the pos. of the coil instead of the negative but we got it to where the only wires on the coil were the run and start power wires, and the ground. and everything was the same driving wise so theres a few wires on there that seem useless. oh yeah and one of them is tied to the stray black wire and if its off the black wire has no power to it. if anyone knows what these wires are that would be cool. i looked at a 72 wiring diagram and i couldnt figure out which ones were for what

[1973240]

Could be no damper oil in carbs too.

is that what those are on the carbs? im used to american v8s and i had never seen those and didnt know what they were for but wondered if the were relevant. how much is supposed to be in there?

[1973240]

I could be completely wrong here but could it possibly be a timing issue? Maybe it's not advancing and that's why the car is dieing when you try and drive it but runs fine in neutral? I'm also pretty new to Zs, so I'd wait for some more experienced members to weigh in before you buy/attempt to fix anything.

.

we tried that too and it didnt do anything either. yeah glad to see washintonions myself .