My 84 GSL-SE starts and idles perfectly, except in the case when it's already warm. In this case, it idles at around 400 rpms and fluctuates a bit, for about 5 minutes, and then it finally goes back to normal. It never dies or anything, but it feels like the car is not sure about what to do. Is this a problem with the hot start assist mechanism?

 

...anybody?

 

The hot start on the SE consists of the air temp sensor in the RE-EGI box and the solenoid with the orange connector (pressure regulator). What is suppose to happen is that if the temp of the sensor is above 122 *F, the ECU sends a signal to energize the solenoid. This will cause the fuel pressure regulator to reference atmospheric pressure instead of manifold vacuum. This will increase fuel pressure about 9 psi at idle. The solenoid is supposed to be energized for about 60 seconds (idle should be a bit higher (about 850 rpm) during this time) and then switch off. There is a test in the FSM to verify that it is working correctly. Make sure the air temp sensor is reading correctly as it is also used to control the BAC valve.

Also, check the coolant temp sensor (on back of water pump) and the AFM. These also will influence how the car runs. I think that you have already checked these, but just letting you know.

Maybe also check you idle while warm (is it about 800 rpm?). Check the timing out as well.

Kent

 

My SE had a slight problem idling after a hot soak last summer. Since then I've had my fuel injectors cleaned and tested. I don't think the problem has came back since then, but its been much cooler here now. So maybe you could have some leaky injectors and it's slightly flooded and when it clears up it idles fine.