Is your tachometer connected, with the inline resistor in place? I had found in the past that my 76 and a 78 parts car would not start if the tachometer was disconnected. It appears to do something to the signal on Pin 1. I never figured out what, but I did confirm it a couple of times. On the 78 I had the tachometer out and on the 76 I had the resistor removed which disconnected the tachometer.

8 hours ago, Zed Head said:

Seems like the main question is "what happened between then and now?" The cracked AFM hose could stop the AFM from functioning, but the engine should stil start for a few seconds on cold start injector fuel.

Maybe your spark is too weak. Are you seeing s strong blue spark or a weak yellow spark? You might try starting fluid to see if you can get it to fire for a few seconds.

Another possibility is flooded/fouled plugs. Have you pulled a spark plug to see how it looks? I'd do that, it's easy and quick.

8 hours ago, Zed Head said:

Seems like the main question is "what happened between then and now?" The cracked AFM hose could stop the AFM from functioning, but the engine should stil start for a few seconds on cold start injector fuel.

Maybe your spark is too weak. Are you seeing s strong blue spark or a weak yellow spark? You might try starting fluid to see if you can get it to fire for a few seconds.

Another possibility is flooded/fouled plugs. Have you pulled a spark plug to see how it looks? I'd do that, it's easy and quick.

I installed new coil, plugs, wires, cap and rotor. Spark was weak not enough to cause a no start I believe.

7 hours ago, Zed Head said:

Is your tachometer connected, with the inline resistor in place? I had found in the past that my 76 and a 78 parts car would not start if the tachometer was disconnected. It appears to do something to the signal on Pin 1. I never figured out what, but I did confirm it a couple of times. On the 78 I had the tachometer out and on the 76 I had the resistor removed which disconnected the tachometer.

Tachometer is connected and where if any is the resistor? I found this barely grounded to the distributor what is it?

8 hours ago, dtejada said:

Tested injector pulse just now and drops form 12.5 to 10.4 both sides of the pin and no pulse.

The best way to test the injector circuits is with a fast-acting light like a NOID light or with a spare injector. If you find that the injectors aren't being opened by the ECU then you can focus on that. But you might find that the injectors are being "commanded" open but aren't. They can rust shut. Or maybe they are opening but they're squirting water. Maybe you put 5 gallons of diesel in by accident. Just kidding but the point is that you seem to have everything you need except good fuel squirting. If it starts with starting fluid you have spark and proper timing.

Is your cold start valve still installed and connected? It's easy to remove and you could check that it is squirting good gasoline during the start procedure. You could also install it on one of the injector connectors, I think it uses the same EV1 connector. I've never tried that though. Could be interesting. Don't forget that the hose will be pressurized if you remove it from the hose. If you can keep it connected to fuel but get an injector connector plugged in it might tell you something.

But really, a NOID light is the way to go.

Edited March 24Mar 24 by Zed Head

SOLVED:

After chasing a no-start, I narrowed it down to no injector pulse. Decided to stay focused on the EFI harness instead of jumping around.

Went through and unplugged/inspected all EFI connectors and started cleaning them. One connector stood out—pretty corroded. Hit it with a pick and CRC electrical cleaner, plugged it back in, and the car fired right up.

Before this, I had already replaced the AFM boot, coil, plugs, wires, cap, and rotor thinking it was ignition related.

Question is—was that the TPS connector and could that alone really cause a full no-start/no injector pulse?

Edited March 27Mar 27 by dtejada
Edit

My only response is I went through the same situation. I replaced every connection on the RFI system due to corrosion. Fix one another pops up. Including the AFM connection. It’s not fun, Takes time but worth it.

Was the same with my ’77 280z. A good start is to clean all the electrical connectors in the engine bay with contact spray and a brass brush. The brass brush is firm enough to clean the connectors and really get in to them but not damage the plastics.

These EFI systems are a bit weir sometimes. Mine ran really rich on idle no matter what I did but I started her yesterday for the first time in a couple of months and the AFR was right on the mark for both idle and power. Maybe she just didn’t like the cold?

Edited March 27Mar 27 by Mitchel0407

Need suggestions. Need suggestions from the S30 guys. Opened up my 280Z headlight/combo switch and found one of the copper contacts keeps slipping out of its swivel/pivot seat because one of the little retaining prongs is broken/missing. Anyone run into this before or found a good fix?

The easiest solution is to replace. Someone probably tried to fix it in the past.

2 minutes ago, SteveJ said:

The easiest solution is to replace. Someone probably tried to fix it in the past.

Well, let's add this to the list I guess, just when I was making progress, they seem expensive just by looking on Ebay.

Make a post on the wanted list in our classified section.

I had purchased about 5 broken headlight switches a while back as parts pieces. I am not sure what years they all are from.

Perhaps one might have the component you need.