129k, fresh HG's, block and head rectification, bearings, etc. History of not starting when hot, threw a 14 code, replaced CST. Fan clutch does everything like the guide says. Today I took the drastic measure of removing the A/C Condenser, thinking it may have been acting as a block to airflow. "Reinstalled" both fans, drove it up the hill which acts as my test drive, slow and semi-steep, using electric fans (have routed a switch, so I can manual override the sensor). Car did not seem to get so hot, but when switched off, still would not start until I cooled it down for 20 minutes or so. I have relocated dist amp from it's previously relocated position right beside the radiator tank, to behind the headlights. I understand the fuel temp sensor could fit this scenario, but it has never thrown a code. Right now I have a 14 which I cannot seem to clear in the usual manner. Any idea why this car will not start when "hot"? I don't know the temp, don't have laser available. Right now I don't have the funds to throw at troubleshooting in the same manner as the mechanics. I need to find the answer in theory. HELP! Bill

 

It's me again, I also replaced the thermostat with squiggly thing in hole and 180 f..

 

Update..30 minutes later. Seems the CST had indeed hard failed, the new one. Aftermarket junk, ought to be a law against china building anything! My old one, even though it had thrown a code, passed all the checks carefully done and documented, so I reinstalled it and will go for a test drive now. I have decided I can check engine temp by measuring resistance on the coolant temp sensor once I reach max temp at the top of the hill, lets see what happens! Bill

 

Update, 2 hours later...Test drive proved my old CTS was indeed good, no codes, no problems. It even restarted after reaching the top of the hill without use of aux fans on the way up! A resistance check on the CTS (180) showed me to be at about 212 f, maybe I have cured the temp problem by getting rid of the condenser, a decent trade off since we don't use AC down here and this one wasn't working anyway. I had also failed to mention that I was missing the top piece of the fan shroud, made a new one, seems to have maybe helped. I am going to claim victory, for now. Even the click from previous threads seem to be getting better. If I could just figure out a way to eliminate the brief idle at 2500 RPM every time I start this thing, I will indeed be content. I have run it without the stepper hooked up and it was sweet to hear it start like a normal truck, but I would rather not live with the codes and CEL. If anybody knows how to accomplish that I would be grateful. Thanks to all who helped! Bill

 

One more comment. I had previously reported engine rattle/ping when engine was put under stress and at temp. Retarding the timing got rid of the ping, but then the engine would not start when hot. I have a loose timing chain that I have been advised is the possible cause of that situation. My vacuum advance unit seemed to check OK, except that it was obvious to me that the puny bit of vacuum available at the normal source was not going to even move this thing. I deduced that a strong vacuum supply would indeed advance the timing during start and light operations, but I needed to timing to retard at heavy operating pressures. I connected to a port on the passenger side of the plenum near the base. That one will suck the chrome.. well you know, and then back off (decrease) under load, thereby retarding the timing, exactly what I needed it to do. Test drive proved that my theory appeared to be correct, I was able to climb the hill at operating temp with barely, if any, rattle. I was able to restart normally once there and shut down. This is a fix, if it is indeed a fix, that I had not read about anywhere, but after studying distributor advance theory, it seemed to fit the situation. Would appreciate comments, advice, suggestions, etc. Bill

 

You may also be fighting the engine fuel temp sensor. It pokes out of the fuel rail. If fuel is hot, it tells ECU to make pulses to injectors wider to flush out vapor lock bubbles on a hot restart. The sensor reads about 9100 ohms at 14F, dropping to 150 ohms at 212F. At 104F it will be about 1200 ohms. Wrong value and ECU may not "help" with hot re-start.