I have a 1990 Volvo 740 Turbo. Its got about 215,000 miles on it. It always starts right up every day for the first time. I can go to work, and let it sit, and then when its time to go home, it starts up and I can get home.

But if I went to the store, go into the store, and come back out 15 minutes or so, it wont restart. It doesn't even crank. The radio works, the fuel pump is working (I can hear the relay clicking), and there is power getting to the distributor. If you let it cool down, then it will crank and start right up.

It happens alot more when its hot. During the winter, this didn't happen at all. I am trying to figure out what it is. I've changed the fuel pump relay, battery, crank position sensor, and fuel pressure regulator within the last year.

Would it be the ignition switch? Maybe when it gets hot, the electronic contacts are not touching to send power to the starter?

The main thing is that there is NO CRANK. Its so random, that I cant really test it.

Any info would be helpful.

Thanks
Vu