Cold start valve wouldn't be the problem. Fuel overheating and "boiling" in the fuel rail would be.
Do a search on how to get around it. Does your car have the injector cooler fan? (looks like a funnly blow-dryer on the side of the engine coming over the head and onto the injectors.)
Do a search using the words "fuel boiling" or "gas boiling". It's a common and mendable issue.

 

Thanks for responding so quickly and yes it does have the blower for the injectors which works when the outside temperature is very hot. Thanks also for the search suggestions. CW

 

My 83 had very similar problems when I first bought it.

Check the ignition module, the black square on the side of the distributor. Pull the dist cap off and make sure the red and green wires are secure in the top of the ignition module, and make DOUBLE sure that the red and green spade connectors are not poking sharp bits of themselves into the insulation of each other. Mine was doing that, which now and then caused the pickoff coil to short to itself. Check and reseat the two wire connection leading to the main ignition coil.

Check the two heavy black wires from the battery positive post to the fusible link box (right next to the battery). Make sure they are making excellent contact and are not corroded in any way. Make sure all the fusible links in the box are also making excellent contact and are not corroded, nor overheated or burnt.

Inspect the ignition switch on the back of the ignition key cylinder, make sure that the wires have good contact, and that the connector is fully seated.

Inspect the connectors to the air flow meter next to the radiator, and the throttle valve switch on the side of the throttle body.

My car had problems in all those places. It runs pretty well now! Good Luck

 

Wow awesome post of things to check. I am off tomorrow so I will check everything you mentioned. Thanks so much, CW

 

If it isn't either the ignition module or ignition switch (which it probably is),check the main fuel injection relay. Either way, get a noid light to plug into one of the injector connections and see if it lights up when you are cranking. If so, pull off the fuel line and point it away from the engine compartment and crank to see if you get fuel (carefully). Or pull off a spark plug wire and stick a screwdriver into it and put the metal near the valve cover and crank to see if you have spark. (Don't do the fuel check and spark check at the same time, if you value your skin) That will narrow down your search.

 

Guys, a key thing chaine points out is that it only happens for a while after he shuts down a hot engine. Once its cooled, he apparently has no problem. It's not a regular "all the time thing".

 

my 80zx does the same thing. starts right up when it's cold, but after it warms up and you shut it off and try to restart it turns over about 30 times before it starts up. other than the warm starting thing it runs great. this morning the outside temp( where the car sits) was 8 degrees. the car started right up. when the weather warms up i will try the suggestions here.

 

Check to make sure the fuel hose isn't up against the block or radiator hoses. The heat transfer will cause vapor lock.

 

A few days ago I noticed a slight leak around the line that goes into the cold start valve. I know that when the engine is hot it is getting fuel because when I went to pull the line off there was a lot of pressure and I ended up putting a rag there and very slowly letting the pressure off so I could pull the line off. I found that the cold start valve had a plastic in line at that point so when I reinstalled the line I was careful not to overtighted it and crack the line. So if anyone has a similar problem you will know that also. Easyguy 71 correctly pointed out that this is a regular ongoing problem when the car is warm. I live in AZ so right now the temperature is in the 50's in the morning and it does this if I stop on my way to work. I am going to spend some time today and check out all the points mentioned and a big Thanks to everyone for the timely posts. CW

 

My '78 had the exact same problem and it was the main fuel injection relay. The relay can still click like its supposed to, but if there is not enough voltage sent to the cts during cranking, no pulse is sent to the injectors to fire.