The solenoid on my vapor can of my 85 camaro gets really hot. It is uncomfortable to touch. I thought it might be broken, so I got a junkyard one, which also gets rediculously hot. Are they supposed to do that? What do these solenoids do, and what is the harm in disonnecting it? thanks.
-Brendan

 

Toe,

Welcome Aboard!

the solenoid will get hot when it is energized. That is normal. What may be abnormal is that the solenoid is energized when the vehicle is not moving. From all the ECM programming I've seen, the EVAP purge should only operate when the vehicle is in motion, at moderate cruise loads, and the coolant temperature is above a specified level.

Having stated that, the 1985 and earlier ECMs were not quite as robust as the later examples, and may have different operating characteristics. On your '85, some of that EVAP control may be accomplished via the vacuum source to the solenoid valve itself, but the solenoid coil should still only be energized under certain conditions. As long as it is still functioning, I wouldn't be too concerned.

 

Thanks for the warm welcome, and for responding The solenoid is always hot, moving or not. The whole vapor can setup is basterdized on mine. it uses a later style can, and the solenoid is just loose there, connected to the hoses.
What is the purpose of this solenoid? What would happen if I ran without it connected?
-Brendan

 

You have a short to ground somwhere in the wiring back to the ECM.

The ECM provides a ground to complete the circuit if I remember right, so somewhere before there, it's already grounded and causing the circuit to be continuously hot.

 

thanks man. I'll get to work tracing that. the solenoid on my brother's seems to have the same problem. his gets even hotter it seems hahah.