Hello,
I posted recently about difficulty starting the car. I'd have to wait after driving short distances up to 15 minutes before the car would start. I thought it was a weak battery or alternator. I replaced the battery, and the carbon brushes in the alternator, and this seemed to fix the problem. Until recently.

Now, if I try to start the car after driving for an extended period of time (say more than 20 minutes), I have to wait until the engine cools down before I can start it again. The engine turns, so I don't suspect the battery (consistently 12.8 V or higher, and above 10V when cranking), and my plugs look good (cleaned and tightened anyway). Whenever I try it in the mornings, or after work, it's fine, starting up quickly with little or no cranking. Car runs wonderfully otherwise, only leaking a little oil (probably need to clean flame trap/breather box).

Has anyone had a similar problem? From related posts I'd read about something called the "Radio Supressor Relay" having prehaps going bad and affecting starts.

Car is a 1989, 740 GLE, 16 valve DOHC. 180,000 miles. Timing belt replaced at 150,000, and harmonic balancer replaced at 165,000.

Thankyou!