mixon123

Hello fellow z lovers, I want to say I look forward to contributing as well as giving some of my knowledge on the way.

I just recently bought this bad boy not running 83 280zx n/a. I did a total engine rebuild from the crank up new bearings, rings, valves gaskets the works. Upon engine rebuild I did a full test of the control unit, EFI and all connectors and switch's and injectors, all was good except a cold start switch, bought a new one. The distributor didn't have bearings rolling around or anything but I took her apart anyways. I come to find out the IC ignition unit is done with the vacuum controller is dead and the magnet is broken as well as the breaker plate plastic 3 bearing washer/holder thingy, commence the rebuild ...all new parts dirt free all better. All vacuum lines are good, the a/c was pulled before I got it, and all the a/c vacuum lines and electric connections are still in place and connected.

Now time to bring this beast to life!!!! I have timing gun all hooked up just to see where I am at on timing, before I let warm up and adjust timing.

Cold start

(FILM A)
Warm

(FILM B)
Now the timing was around 8 degrees BTDC on first ever start up, so Film A is after the timing is correct at 10 degrees BTDC, but I achieved the same results perfect advancement, 18 degrees at 2500 rpm.

I'm feeling pretty damn good right about now , no leaks he's running perfect, so idling now and warming up for the timing adjustment.

As he's warming up I started to notice the idle was getting just a little weaker (I think as it should) but hooked up the timing light to take a look anyways and this is what I found.(keep in mind the timing set in the film is after I put it on 10 degrees all the same just 2 degrees different) Film B The timing is 8 degrees as soon as any RPM are applied the timing jumps straight to 0 degrees and starts to advance from there WTF. So I waited to he was all warmed up and notice the closer I get to running temperature he does not like to idle like... 300rpm and dying. So I took 5 steps back and did this and a little of this - the smile

So I am completely lost at this point and any advice or direction pointing would be awesome, Thanks Zdriver Nation

Mixon123

p.s Maybe I need to retest everything... The only thing I have not tested are the blow auxiliary cooling fan and this thingy just right and a little lower than the cylinder head sensor in the bypass hose, its just not in my Haynes book what gives.

mixon123

And this thingy right next to the Thermo Time Switch.......is not in my book either, nor did i test it. Its right in the middle of the picture left of the thermo time switch in the cooler housing. Basically there are to single plug wires coming off the distributor wiring harness out the side of the fender and are hook up to the EFI and one goes in thingy in the picture and the other goes in the housing just right of the thingy and i have no idea what they are.



Mixon123

NismoPick

That's the coolant temp sensor for the Auto Climate Control.


The single "bullet" sensor is for the coolant gauge on the dash. The pigtail sensor is for the aux fan.

From this thread: https://www.zdriver.com/forums/280zx...sensors-36716/

mixon123

Thanks so much NismoPick, I forgot about the FSM

The good old FSM files ok, super awesome help. I pulled the thermo time switch out and gave it another test, (Haynes book says test at 50 and 86 degrees and work up) the only reading I can get on it is 57 ohms, doesn't advance in ohms at all. So the switch is bad. Can this cause the engine to do what it is doing in film B warm start. I just can't see how the ecu sends a signal to the distributor to fire late .0009sec to make it fire on the 0 degree mark.?


So in the mean time I am going to buy a TVV, TVS and CHTS and all new connectors to these. CHTS, TVV works, so I will have back ups!

Happy memorial weekend!!!!!

mixon123

I have a headache......

The Therno time switch tells the cold start to stop misting it up. How in the heck can the switch have an affect on the timing jumping to 0 AT ANY RPMS when warm. Can it do that?

I guess the ultimate question is what are all the diagnostic of timing jumping to 0 from 10 degrees at idle at applied rpms?(And I have a feeling the answer is going to be heat) I going to order these parts if i need them or not.. but I have a big fat gut feeling this is gong to do nothing.

Thanks Mixon123:0 85:

the green dude is my Z!

mixon123

Hello zdriver

The Mothaf@#$%in T.V.V

This thread is going to end very soon......And I am going to give a NOOB Report on the T.V.V Thermo vacuum valve (ported valves switch) and W.T.S water temperature switch and its relationship to the electrical system.

There is simply not enough info on them and how it CAN effect your engine, big time.

It is late and I am pooped, I'll post tomorrow

AND YES THE PROBLEM IS FIXED

Mixon123

P.s If anyone wants to touch light on this subject, super welcome.

mixon123

Well I thought I fixed the problem but its still doing the same thing, except now it can idle when warn (CHTS).

All new temp switches in the coolant housing 3 of them, (water temperature sensing switch I got at pick and pull), cths connector and switch, new distributor, vacuum lines, primary coil, afm.

I have 3 WTSS and I can't get any resistance reading on all of them hot/cold, everyone of the 280zx at the pick and pull had new rotors, rotor caps, spark plugs/wires.

Question can the T.V.V and water temperature switch be the most common problem in people giving up? (original parts)

Thanks Mixon123

mixon123

I love Z's

fixed

I wouldn't pay any attention to my questions above they are
The specifications sticker under your hood is gold when tuning up and doing ignition timing. I had a big problem my sticker is unreadable straight up!!
I was at a junk yard and found a 1983/July 280zx n/a with the hood still on, I take a look spec sticker and there it is laughing at me....



the part where it says disconnect the "spark timing control wiring harness connector color grey"

It is not in the specifications in my Haynes and the FSM has it on MA-46 in a tiny little sentence that i seemed to over look . I think it is super weird that Haynes left that out.

Will now I am pretty much a expert on the 83 280zx Inline 2.8 6cyl

Ill post some pic's when she's all wax up!!

Thank you Zdriver world.

P.s Zdriver is 1000x better than zcar..

Twiggs280zx

Good to know as I will be turning my key very soon

a280drvr

ok so question. This grey connector you all are talking about everywhere, I don't have one. So does the 79's not come with said connector? The only connector I have on my distributor is for my ICM.