[Rendell]

After I put the new engine in my car, and got it out of the shop, ever since, in the morning, when the engine is cold, my engine idles high, I think around 1500. Once the engine is warm it drops to >1000.

 

[Rendell]

The engine is supposed to idle at 1500 when cold. That's a normal function. Your IAC valve was probably clogged before you re-did the engine. Same thing happened to my old '89 mx6 that I gave to my friend. The car didnt have a fast cold idle, so it wanted to stall half the time until it warmed up. After we re-did his cyl head and replaced the IAC valve, it idles at 1500 when cold.

Hmm, thats good to know. I thought something was amis. Thanks.

 

[Rendell]

one other thing

It may have something to do with your thermostat, or Temperature sendig unit. The reason I say that, is cause if the computer "thinks" that the car is cold, it will run a richer fuel to air ratio, and idle higher. The rich fuel to air ratio would explain the poor gas mileage.

Does your temp guage register warm? Mine was always about halfway up.

My sister's car (1991 MX6 LX)was idling @1500rpms also, and her heater never would get warm, although the temp guage always was in the middle too. We pulled out the old thermostat, and someone had taken out the spring, and valve (bascially all that makes it a thermostat). We put in a new thermostat, now the car idles good, and the heater is warm. The temperature guage still goes to the "halfway" mark. I don't understand that, but oh well

Just a thought, good luck.

Temp reads cold until about 5min after being run. Then the guage will never go past the hlaf-way mark, but it is usually there when the car is running. And my heater works great, as does the AC.