Last friday after a long hot drive, I could not start my 89 745T after being stopped for 5 minutes. When I turned the key, I didn't even get a click. Since I was 10 minutes from home I walked, called my mechanic, and grabbed my multimeter and some tools. Walking back to the car I figured I would jump the starter. But first I tried to start the car, and it fired right up. Today it did it again, only it started after 2 or 3 minutes.
Yesterday I visited my mechanic, and he said I might need a hot start relay kit like the one he installed on his wife's 90 745T. He went on to explain to me that this problem on some late 80's-early 90's 700 turbos. Apparently the wiring between the ignition switch and the starter solenoid gets heat-soaked, making current difficult to complete the circuit. After a short cool off period the car will start. I know this is a common problem for small block chevrolets from personal experience. He told me the kit is made by a company called IMC specifically for this and runs about 15 dollars.
Has anyone ever heard of this or better yet has anyone installed one? Thank for any info or feedback.