Hello guys.
D I 1997, 150K miles. No codes. I was having problems starting and after a quick check determined that my fuel pressure was too low and got a new fuel pump. After I replaced the fuel pump the car run great for about a week. Then started acting up. When I stopped the RPM would go very low and sometimes it would even die. I read here to check for vacuum leaks. I checked and found no leaks, while checking I did unplugged the stepper motor and cleaned the contacts. Drove around the block and the same problem, low idle when I stopped. Here is where it gets spooky. I went to bed. Next day started the car and the RPM went to 2k. From then on, it stays at 2K at idle until it warms up and then lowers to about 1200 RPM.

What is going on? Why went from too low idle to too high? There are no codes, and other than the high idle it runs like a champ.
Thanks

 

Your original problem is a bad fuel temp sensor.

You need to clean your stepper motor and the port that it goes into, remove it, clean it with carb cleaner, the port it goes into too.
Use your wifes toothbrush if you need to to clean it well.
All the holes inside need to be obstruction free.
Just make sure you put it back in the correct way and do NOT turn the plunger at all.
Do all of this with the key off.

 

Also, since you have replaced your fuel pump, you should also replace the fuel filter and check and replace any vacuum hoses that are cracked/leaking or collapsed.