Car shuts down/stalls when I stop

[samiseth]

I just bought a 1987 Prelude. Everything seems to work fine except that after driving for 15/20 minutes when I stop and take my foot off the gas it stalls out. I have to keep the RPM's above 1500 for it to keep running. I was wondering if anyone could help me with this. I don't want to drop too much money at a dealership if I don't have too. Thanks.

[spiffyguido]

Do you also have a really hard time starting it when the engine is warm?

[samiseth]

Yeah. It usually takes at least three turns of the key to get it started again and I have to pump the gas also.

[spiffyguido]

Ok. I've have something for you to try.

The next time you have a hard time starting the car, open the hood and disconnect the two-wire cylindrical plug (usually green) that connects to the cylindrical sensor in the thermostat housing. This is the coolant temperature sensor. With the sensor disconnected, try to start the car again...it should fire right up.

[samiseth]

Thank you. I'll try that. But will that do anything about the car stalling out when I slow down or stop without giving it gas?

[spiffyguido]

It will help you to determine whether the Engine Coolant Temperature sensor is to blame for your problems. If the car fires right up with the sensor disconnected then that's a good indication that it might be related to your troubles.

I've personally experience the symptoms that you described on two occasions and in both cases the ECT was to blame. Not to worry, it's an easy repair to swap the sensor out if it turns out to be bad. They do wear out with time, so it doesn't point to a more serious problem.

[samiseth]

Thank you for the help. The guy I bought the car from is being really cool to me and had it towed. I will talk to the mechanic about what you said. I didn't know the seller was going to be cool about this and thought that he would tell me that its my problem now. Thank you for your help. I'm sure I'll need it again if I get the car back.