Car Idling Bad On Startup When Hot

['95EclipseGSX]

So for the past few months (maybe 6) my car has been having difficulty idling sometimes when hot. This only happens when the car is warmed up. I will turn on the car and it starts, the RPM's go up to 1,400 or so for a tiny bit but then rapidly decrease until the engine is at 600 RPM. Then the engine jumps around between 500 and 700 RPM. (Normal idle seems to be 750 for me) Yesterday the car actually died for the first time. The RPM's went down to 550, then they started to hop around +- 150 RPM until the engine went too low and died. This took maybe 5 seconds. I tried stepping on the gas (full-throttle) but it didn't do any good. Didn't do anything actually. When I started it again I made sure to give it some gas immediately; before the RPM's dropped down below 1,000. It worked and by the stop sign at the end of my street, it was idling normally again. This doesn't happen on every warm start, just randomly. I thought it might be the front o2 sensor (it was out for a while) but I replaced that last month and it obviously didn't fix the problem. Anyone have any ideas of what this might be? Fuel filter? Severely damaged engine & costly repair? I have no idea. Thanks!!

 

[GRAVEDIGGER]

Sounds like it could be a bad coolant temp sensor or a loose/broken wire on the sensor. It's located on the bottom of the thermostat housing and you can test it with a multimeter set to read ohms. It should read about 2500 ohms at room temperature (60-70*). I've included a picture to help you know what you're looking for.

 

['95EclipseGSX]

Cool, thanks for the info. I am going to test it tomorrow morning and am wondering how exactly I do it. Where do I put the multimeter to get a reading? Does the car have to be on? Or in the on position (so the power is on)?

 

['95EclipseGSX]

I tested the coolant temperature sensor and it apparently works (read correct ohms). Darn it!! How do I test the wires to see if they are faulty? Is there anything else I should check?