After having this problem diagnosed and fixed over one-year ago by an experienced mechanic, who replaced the ignition modulator, distributor (which was cracked)and dist. cap, there is no spark when engine has been

running when the external temperature reaches 85-90 degrees. Lifting the

hood to ventilate helps to cool engine and then it will start. Any other suggestions?

as dumb as this may sound but did you replace the sparkplug wire?, additionaly have you checked the coil for power? those coils do funney things when they take a shit on ya. Is the dist is new i really woudnt be looken anywhere near there, though if the car is hot and it doesnt start and is a turbo i would look anywhere around the turbo for electrical, on the 86 the wire harness runs right around the turbo and heats up like a hotplate. the coil alos is above the turbo on the 86 model. also just a recomendation buy the spark plug wires with the metal heat since around the connectors to the plugs, this will save you allot of trouble in the future as those plugs heat up big time, with that metal sinks there it helps a whole hell of a lot. I would really though check the coil first and thats where the power comes from for the spark.

good luck

You may have a bad Hall effect sensor. Does the tach needle bounce when you attempt to start the car, when hot? There is lots in the 700/900 FAQ on the ignition including the test procedure on the Hall effect sensor.

The tach needle does not bounce. Isn't the Hall effect sensor attached to the distributor or am I mistaken? I replaced the distributor last year because of this problem.

Ok well if it isn't the sensor it could be something in the circuit, the hall module or whatever it is that doesn't like hot temperature, some worn out chip or electronic gizmo.

How much do the hall sensor boxes or modules cost though.