My late 1987 GN refuses to start when hot and has been sitting for 30 minutes or so. It starts instantly when cold, and it re-starts when hot after being shut off for only a couple of minutes. The problem occurs after it has been sitting roughly 30 minutes. The engine turns over as it should. There is even a small hint of firing at times, but not enough to keep the engine running. I have had this car since new -- and this is the first time this has been a problem.