Won't start when cool

[AndrewWake]

I have a 1980 280ZX it has been having issues starting. When I try to start it in the morning (like 40 degrees outside) it will crank but wont start. In the after noon (65-70 degrees) it starts fine if I give it a little gas. But this morning I tried to diagnose the problem, and there is no spark. Does anyone have any ideas what this might be? The battery, ignition module, ignition coil and voltage regulator are all new.

[Zed Head]

How did you diagnose "no spark"?  

When you "give gas" to an EFI car all you're doing is lowering intake manifold vacuum, and taking the throttle off of the idle enrichment setting.  Shouldn't have anything to do with spark though.  You might be getting your symptoms mixed up.

Will it start with starting fluid?  It sounds little bit like you have weak spark.  There are other causes for that besides the parts you changed.  Have you looked under the distributor cap lately?  The ZX distributors aren't very durable, they're known to wear out.  Bad bushings, broken magnets.

[Reptoid Overlords]

If the idle air adjustment screw on the AFM is out of spec, will ambient air temperature affect cold idle?

I can't remember what happens when I tighten mine all the way in while the engine is running , but I seem to remember it stalling out.

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[Zed Head]

Actually you bring up a point that often gets overlooked - is this a new problem from out of nowhere, in a car that ran great?  Or was something adjusted and now it doesn't work right?

Edited April 20, 2019 by Zed Head

[Reptoid Overlords]

My mistake.. The idle air adjustment screw is on the throttle body, not the AFM. Apologies if I muddied things up.

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[AndrewWake]

Thank you for the replies, no, I did not do any adjustments it was running fine last saturday in the cold. Reptoid Overlords- If you tighten that screw all the way it just stalls.

Update on the status- I went through the Nissan service manual and narrowed it down to the bearings in the distributor. I took the distributor appart, some of the bearings for the vacuum had fallen out, so the vacuum wasn't working properly.

[Zed Head]

14 minutes ago, AndrewWake said:

Update on the status- I went through the Nissan service manual and narrowed it down to the bearings in the distributor. I took the distributor appart, some of the bearings for the vacuum had fallen out, so the vacuum wasn't working properly.

Check the magnet under the stator ring.  It's probably broken.  The timing could be stuck in the advanced position.

Either way though, you can't get repair parts.  You'll need a new distributor.

[Pilgrim]

Or a used distributor with a functional part....