Need some help diagnosing...

[syfir]

First of all sorry about language. As for the heat, it is cold air, as if I had the blower motor on but neither the heater or AC switched on. The engine takes a very long time to warm up and will not usually get much above the bottom of the temp gauge unless taken on the highway. As far as it running different, the car starts up a little quicker(there was some corrosion on the old rotor) but it does not run noticeably different. The reason I mentioned the thermostat, is someone before had mentioned that the ISC monitors the coolant to control the idle speed. If the coolant is cool all the time, is it possible it is always idling cold(as opposed to hot idle)?

[turqfest]

ISC function....not perfect but something like this......
the ECU sends a signal to the ISC to increase air flow to the engine at idle. As air flow increases the VAF provides feed back to the ECu thus the ECU also increases fuel flow. The signal to the ISC is proportional or PWM (pulse width modulated).

Anyway, the hot water works internally on the other side of the ISC valve with a wax motor. If the water is hot, the wax heats up...expands...and closes the valve.

Analogous to the choke on a aspirated engine.

Maybe not perfect....but I think I'm pretty close.

Thank you for that brief description - I found that extremely useful!

Syfir

I have been having similar problems to what you speak of. It seems to be quite an intermittent problem.
I have replaced both my cooling fan relay and thermoswitch (both defective), so if it helps, you might check that out. I will be investigating the ISC-BPA this weekend, The description of what you've been experiencing sounds very similar to that of my own. I have also replaced my cap and rotor as of yesterday.

According to my Haynes manual the resistance between the two terminals on the electrical connector should have a resistance of 7.7 to 9.3 ohms - Can anyone tell me if that is correct for a 90-93 festiva?