Car starts and runs fine when cold

>car starts and runs fine when cold
>starts to run like shit when it reches operating temp
>will not restart when hot if you turn it off
>Fuel pump and injectors are working
>won't even fire with starting fluid
>getting spark from coil to distributor
>plugs wires cap and rotor are all new
>Literally just started happening after over 8k miles with 0 issues
It's obviously an ignition issue but it makes no fucking sense how it only turns to shit when hot. Any ideas why my shitbox is being a dick?

it's american probably

Year, make model

80s Nissan
Made in Nippon

1986 300zx non turbo 2+2 manual

pics or you're lying

soviet btfo

i got picked up by a friend and its sitting in a parking lot so no bread on hood
why the fuck would i lie when i need help

yes, why would the devil lie

Sounds like a cooling issue?

Maybe start with a coolant change, radiator cap, and new thermostat?

Coolant temperature sensor?

coolant and cap were changed soon after i bought it, thermostat is ok because it always stays in operating range

It's a long shot but check your throttle position sensor connector for corrosion. We had one with similar problems. and cleaning it fixed it up. Also its possible your O2 sensors are going out and when the vehicle heats up, the computer kicks on and reads values and adjusts engine accordingly.
Also that car has a good cult following.
You may get better info on model specific forum than Veeky Forums

not sure if the ecu uses a different one than the gauge but if theyre the same then its ok.

ok ill hit them with contact cleaner and a brass brush. o2 sensors sound possible too, can i disconnect or bypass them to get it to run until i can order new ones?
unfortunately the z32 is the popular one, the z31 is the red headed stepchild. i do post on a z31 forum but it takes nearly a week for anyone to respond because its such a dead community.

This its probably emission equipment related.

Check if running rich when hot.

>Fuel pump and injectors are working
Yes but *are they really*?

Probably do this:
Gas engines only need 3 things to run, air, fuel, spark.

well now that i think about it, the tps on the manual z31 only tells the computer if its idling or not, the wot pin is disabled and it doesnt give any position feedback thats all on the maf. and i dont think bad o2 sensors would cause the engine to not even fire on starting fluid.

dont know how without putting in a wideband

yes there is white fuel smoke coming from the exhaust after cranking and plenty of fuel pressure all the way up to the rail.

Just remembered, check the fuel regulator connector too, make sure its still there.
Be careful handling it cause it think its a one tab terminal that can break off super easy.
And hey its also possible the fuel regulator may have gone out too.

ok ill check that one too. why would that cause no start to fire though? maybe its stuck open and as the engine warms up it goes too rich to ignite the fuel mix or something>

...

Sounds like vapor lock to me.

but how will i know i am actually running rich

it did to me too, but the car ran through 90+ degrees all summer literally without a single issue, but now its in the 60s-70s and its doing this. also i thought efi systems almost never vapor lock and it if it is vapor lock its even doing it while running. finally vapor lock wouldnt cause the engine to not fire on starting fluid.

Lay some bags of ice on top of your fuel rails and injectors.

>but how will i know i am actually running rich
Take a look up your exhaust pipe lately? Or ever flush it out? It should be spitting fuel out the exhaust long before its too sickeningly rich to run at all.

The worst that's come out of the pipe is a bit of white smoke after extended cranking or a ton of black smoke when it's misfiring while running

Ok yea the black smoke is way too rich indeed..

Have you tried starting it and holding the throttle open a bit? That should bypass the idle circuit settings, maybe that'll narrow it down.

Tried that for more than 30 seconds straight, just cranks over with no firing at all

Plugs could be fouled to hell from all that over-fueling and just be RIP, might need to bite it for a new set to diagnose. I'd do it anyways since you need to be able to "read" them to find out what the heck is going on.

good point. i would be pretty happy if it just needed a new set of plugs. ill go ahead and pull them and take a look when i go back to get it.

ECU is KFC

Be me, drive comfy 2011 Passat with all the bells and whistles. One day the various computer controlled gadgets began to malfunction one by one, first it was the self adjusting volume controls that are supposed to match radio volume to road speed and such, the mic elements went bad and now it will randomly turn its self waay down or decide to blast me out of the car at random stoplights.

A week later the computer decided to only display gibberish or a partial MPG reading amd nothing else, everything kept working fine, so I carried on.

Finally had to take her in to my mechanic, a great place here in OKC called the Car Doctor, a shop complete with even a fat shop cat. I had to take her in for inspection finally after starting it to leave for work and the dash cluster light up like a Christmas tree and refused to return to normal. Inspection found corrosion on contacts and even on the board itself, like cause was a condensation build up from the air conditioning leaking water that vaporized quickly during the 110f summers we have and it leaked through the dried out plastic housing that had developed cracks. I loved that car so much but I had to give her up after seeing that repair bill, still hurts.

Also, while we help OP, car problem feels thread?

That was some... ..something.. you just posted right d'ere.

Feels story:
I fixed a thing I didn't realize was broken, car runs better now. Good feel.

Grok car go good, feel good. Grok car no go good, feel no good, Grok feel baaad.

Grok feel better now.

Op here I went to go pick up the car and sure enough it's dead cold and fired right up and drove home without much of a problem until it started to warm up when I was almost there.
I'm going to let it cool back off and then check spark plugs O2 sensors and all that other shit at hopefully I'll be able to find the culprit for this fucking thing.

Had a similar problem with the family shitbox years ago. If we turned it off when hot, it would refuse to start.

I don't exactly remember what the fix was, just that it had something to do with some coil. I'll ask my dad, he might remember. I doubt it would be the same thing, but our shitbox was japanese as well, so something might be similar.

ignition coil?

Swap in a LS. That should fix the problem

Literally that's my long term plan for this thing after I finish school and have money to play with

Might be. Can't reach dad as of now.