[Leonard Welch]

Hey All,

Anyone out there familiar - I mean really familiar with the 1971 TCS system?

Here's my story. I've had this car for almost three years and I've been unable to fix this problem. I can't get the system to work. My car idles high due to a constant vacuum advance caused by the inoperability of my TCS system. Strange thing is that the fuse pops at each cold start. This fuse also contains the radio and idle stop solenoid circuits in addition to the TCS system. Warm starts will not blow the fuse. Strange thing is that once the car is warm and the fuse is replaced, the TCS system still doesn't function as it should - which is (per the Service Manual) no vacuum advance unless abnormal operating temperatures (under 80F and above 220F) or transmission in 4th gear (I have a 4 speed 400).

I've made sure that the vacuum hose routing is per the Service Manual (because there are two hose outlets - one is plugged).

I've replaced all of the TCS components - the three-prong temp sending unit, transmission sending unit and the TCS diaphragm itself. I've even replaced the engine wiring harness and the sending unit jumper (car has rally gages).

Since the fuse pops at cold start only (I can make it pop just by turning the key on without starting it), I think that this points to the temp sending unit - or something to do with it.

Any troubleshooting ideas?