1985 Mondial

Try posting this in the Mondial section.

IIRC the Mondial uses the K-Jetronic fuel injection system, same as the Porsche 911SC, 924, and 944. Hot start problems are often caused by a pressure leak somewhere. I had something similar on my 911. It can be a pain to diagnose and fix.

http://www.porsche924-944.nl/924/Troubleshooting.html#when%20warm

 

It is correct that the fuel injection system is Bosch K-Jetronic. Vacuum leaks in hoses do not seem to be the problem as the car starts up fine, cold. There are helper sensors and exhaust monitors in the system. There is the WUR (Warm Up Regulator) that must switch off when the car is warm. And in the Porsche, there is an item called the fuel accumulator if one goes back as far as the mid-1970's. A hard start-up problem sounds a bit like vapor-lock within the system. Now I really know very little about any of these cars. But one of the, "fixes," when vapor lock existed, was to wait 24 hours or at least until the engine was cold and then re-start the car. When this is usually successful, it leads towards a vapor lock somewhere in the fuel accumulator of fuel filter. Sometimes a sensor can misread the condition of the car. Lastly, the Marelli distributor set must be examined for proper advance and retard. How does the car run when warm and running? Any flat spots, etc. -- Zioo

 

One of the information systems in the otherwise simple Boch Jetronic K depends upon some of the wires involved in sending a "one-way" signal. Signals traveling the, "wrong way," can result in a car only starting either hot or cold, but not the other way around. This is a result of the re-installation of one of the diodes in the wrong direction. You suspect this if wiring has come apart in the rear of the car for any reason, such as after an accident or incident which resulted in the removal of any of the rear flank areas of the vehicle, particularly the right rear. The diodes must be installed again in the correct order and orientation to ensure that electrical pulses are traveling in the correct direction. That allows items such as the WUR and throttle body senors to work with the distributor properly so that the car starts without vapor lock or sometimes just as bad or worse, flooding. -- Zioo