1978 280Z - Won't restart when hot, all interior gauges, fan motor, backlighting not working

[Yarb]

So when you changed that out. Did you put the new cap on first and remove one old wire from the original cap and replace them piece by piece to the new cap with the new cable corresponding cylinder systematically. The reason I ask is you have two completed caps and wires in the picture. From the pics I can not tell if you are on the correct lugs. Still don’t see the differences in the caps from the pics provided. Puzzled on my end.

Firing order 1-5-3-6-2-4

Edited October 25, 2023 by Yarb
Add info

[NocturnalEmber]

28 minutes ago, Yarb said:

So when you changed that out. Did you put the new cap on first and remove one old wire from the original cap and replace them piece by piece to the new cap with the new cable corresponding cylinder systematically. The reason I ask is you have two completed caps and wires in the picture. From the pics I can not tell if you are on the correct lugs. Still don’t see the differences in the caps from the pics provided. Puzzled on my end.

Firing order 1-5-3-6-2-4

 

I took the old cap off and transferred the plug wires one by one systematically.  There isn't any marking on the new NGK cap to signify what Cylinder #1 is, so I had to go by lining the caps up side by side for a visual. 

I suppose its not really that visible in the pictures, but the plug wire holes at least to me don't seem to be in the exact same positions. They aren't horribly off, but it seems like the two caps are slightly different. the NGK cap on the right looks like its plug holes are slightly off in their positioning compared to the oem cap on the left.  Maybe I'm just seeing things at this point.  Like, if you compare it to this example I found online, my plug wires follow that cap, but the OEM one I showed a picture of previously next to my NGK cap/wires  looks different.  The OEM one with the taped #1 looks like where the #4 would be in this picture below, but the #1 taped wire is on the hole that has the notch for cylinder #1, so it can't be wrong.

I suppose I might just be seeing things.

 

[Yarb]

Wish I had a motor to look at right now. Hopefully someone will chime in.

[Zed Head]

Rotate the engine, clockwise looking at it from the front to keep the timing chain tight, until the timing mark is at about 10 degrees.  Remove the distributor cap.  The leading edge of the rotor (it spins counterclockwise) should be pointing at the #1 electrode or the one opposite #1, depending on the stroke of the piston.  So #1 or #6.  If it's pointing anywhere else then you have a problem.

 

[NocturnalEmber]

1 hour ago, Zed Head said:

Rotate the engine, clockwise looking at it from the front to keep the timing chain tight, until the timing mark is at about 10 degrees.  Remove the distributor cap.  The leading edge of the rotor (it spins counterclockwise) should be pointing at the #1 electrode or the one opposite #1, depending on the stroke of the piston.  So #1 or #6.  If it's pointing anywhere else then you have a problem.

 

I think I might have discovered another problem, or maybe the problem, I have no idea.  So given my talk recently about the two caps and if they were different or not or if I was just not remembering correctly, I decided to go out there and pull both caps off and compare them side by side. I didn't notice too much of a difference, so I guess the plug wires were just skewing my point of view.

 

However, I did notice there was a chunk of black plastic laying in the distributor. I had no idea what it was from, either.  So I pull it out and look it over. I decide to investigate more, and i pull the pickup off and take a look at it. I have no idea if this plastic is from the pickup or not, but it looks like it *May* be from one of the sides of it.  I have no idea if the pickup is in decent condition or not, as I've never seen one aside from this one.

What I did notice though (I tried to clean the reluctor wheel off with a wire wheel on my drill at low speed by brushing it a few times against the points to maybe clean off any contaminants but without shaving material off) It looks like part of the wheel is actually missing some of the material on one of the points. 

Could this be what is causing my issue? Pictures below.

 

Edited October 26, 2023 by NocturnalEmber

[Zed Head]

Grab the top of the shaft and see if it has play.  The reluctor wheel, the metal star that you're holding, has been known to contact the pickup coil if the bushing gets worn.

There's stuff in the FSM about it.

This one might be easier to do at the terminal where the red and green wires connect to the harness.   But since 1978 has the plug it's actually pretty easy to do inside the car.

[NocturnalEmber]

The reluctor wheel when it was on the distributor itself didn't have much side to side play, it felt pretty secure. The only play I noticed was I could spin it back and forth a tiny amount.

 

I'm guessing for that second one thats the plug going to the ignition control module under the passenger side of the dash I would be testing?

 

Just my luck though, it looks like the reluctor wheel and pickup are NLA. So I'd have to risk secondhand. or upgrade to a zx distributor, but most of the guides I see are for 240z's, need to do some digging.

[Zed Head]

Okay!  Carry on...

1 hour ago, NocturnalEmber said:

it felt pretty secure

 

[NocturnalEmber]

37 minutes ago, Zed Head said:

Okay!  Carry on...

 

 

Sorry about that, I figured when you said grab it to see if it had play, I assumed it was sufficient.  Time to break out the feeler gauge. But I imagine even if it tests within spec, it looks like a piece is broken off both the pickup and the reluctor, so I should probably look at replacing those.

[Yarb]

That one piece of trigger wheel broken off is going to make a difference. You are missing a pulse being sent to the ignition module.

[NocturnalEmber]

On 10/25/2023 at 11:20 PM, Yarb said:

That one piece of trigger wheel broken off is going to make a difference. You are missing a pulse being sent to the ignition module.

Well, a huge positive update for anyone thats bothered to keep up with this thread for the past sixteen pages.

I ordered a secondhand distributor from a known good running car (claimed by seller.) I can't say for sure if the reluctor wheel on my distributor that I pulled off was chipped before I took the wire wheel to the tips to clean it off a bit, but part of me thinks the reluctor wheel wouldn't be that weak to chip off like that with a wire wheel brush and minimal force, but again, I haven't worked on a distributor powered car in awhile, and I've never cleaned a reluctor wheel until now.

So I installed the "new" distributor after cleaning it up a bit, installed the cap and rotor, reconnected plug wires, etc.

I started the car and it fired up and the RPM's immediately shot to 1,500 and held there, which I assume would be characteristic of a cold engine, as thats typically where I've seen them hover.  I gave it some gas, and the stumbling was gone, the car revved happily, with the tach reflecting that.

At this point it was burning some oil though, blue smoke was filling the garage, so I shut it down.  I'm not sure if that's just from how long it sat, or if theres an issue with valve seals or piston rings, but it's my goal to get the car out of the garage and into the driveway in the next week, change the plugs out, and just let it run and get up to temp and see how it works.    I need to bleed the brakes and install new pads/rotors on the front (and a caliper, the right front was sticking I believe, but I bought two new ones, so that's going to happen as well.)

At any rate, The main problem *Appears* to have been solved with the replacement of the distributor. Whether more issues will show their face now that the car is actually firing correctly remains to be seen, and I wouldn't be surprised if that were the case.  I'll have a more full report to make once I can let it idle for a few minutes and get up to temp, but as of now, it starts and runs much more clean, I can give it throttle and let it rev as high as it wants, where before it would hit a wall at 700~ rpm and just refuse to rev no matter how much more throttle was applied, and adding throttle could even cause it to die. 

A minor victory, but a satisfying one!  I still need to figure out the issue with the blower motor not working on any setting, and the turn signal only working on the right (slowly), not working on the left whatsoever, and the back lights not working all the time when the headlights are on, most likely the switches if I had to guess.

Edited November 12, 2023 by NocturnalEmber

[Captain Obvious]

6 hours ago, NocturnalEmber said:

Whether more issues will show their face remains to be seen, and I wouldn't be surprised if that were the case.

I would be disappointed if there weren't.  

Congrats on moving forward.  One step at a time!