Our 2000 626 is having issues with the idle and stalling. When you start it up in the mornings the engine will rev at 2K for a few minutes till it warms up. It has the 2.0 and 5 speed
I know it will rev up a bit when it's cold, but 2K seems a bit high to me.
And if you rev up past 3K to upshift, the RPM's won't come back down, they just stay there. Last night in my driveway I was giving it throttle up to 3K and after I let off of the throttle it would still climb. I had to shut the engine off to stop it. I pulled off the IAC and cleaned it and made sure the plunger wasn't stuck or sticking. If I unplugged the IAC it would kill the engine.
I checked all of the vacuum lines and even sprayed a few quick shots of carb cleaner around the EGR, throttle body & IAC solenoids. No change. All of the bolts are tight, and nothing seems out of the norm.
And my other half says it will die on her at times too, the idle will drop down to 500 RPM's or so then just die. It would start right back up tho.
What else should I look for? Am I missing something?
Any help will be greatly appreciated. Thanks all.

 

Sounds like it has a vacuum leak

 

My Mazda 6 V6 revs near 2,000 rpm at start up as well. But it does come down to 1500 after 20-30 secs. I would start with cleaning the throttle body and the MAF sensor while you are there. Disconnect the negative terminal on the battery before cleaning it. After re-hooking it up let idle for 10 minutes. Don't use carb cleaner. Adding a ground wire from the throttle body to the negative battery terminal may help as well. Inspect cracks on intake before the throttle body as you have to remove it to clean the throttle body.
See this video before cleaning: Rough Idling Issues |*MotorWeek

 

2000's still had a cable operated TB. I'd bet it is the throttle position sensor going bad. This was fairly common in the ealrier cars. The PCM needs the TPS to tell it where it is and if it can't "see" its position, it just goes crazy.

 

How to check a TPS:

 

There are no vacuum leaks. I have cleaned the throttle body and IAC motor.
There seems to be a large amount of carbon buildup in the throttle body, and on the throttle plate as well as the intake runners. More than I think there should be.
There was a lot of carbon buildup on the IAC plunger. I carefully cleaned it, and it seemed to help a little bit, but after a few minutes, it started acting up again.
My wife drove it to work the other day, and she said at about 60 in 5th gear, it would jerk and sputter, and if she put it in 4th, it would go away. And now it's starting to die at a stop sign.

 

change pcv valve and you probably have egr valve problems. If egr valve is stuck open it will cause your motor to die at a stop light.
Egr needs to be cleaned.

 

I checked and cleaned the EGR valve. It wasn't sticking, but I cleaned it anyways.
I checked the ohms, and voltage at the TPS, and the ohms seemed to be ok, but the voltage never changed. Is that possible? I have a cheap analog tester, and the ohms dropped off as the throttle opened up, and I then checked the voltage. It's getting 5 volts to the TPS, but when I opened the throttle, the voltage didn't fluctuate.
I checked the voltage with the ground at the battery, and at the switch. I checked pins 1 and 3 on the TPS. I don't have a manual, those were the pins the guys at Autozone said to check.
Now when I start the car, it will shoot straight up to 3K and stay there. I can't even drive it.
So I'm guessing the TPS is bad. What I can't figure out is why the parts are so expensive. Go figure.

 

This is why we tell you to do the other stuff first! ----- Because replacing those parts is expensive, and you might get lucky with a cleaning.
OE parts from Japan and depending on where you live. I live in Canada and it's more expensive here than in USA.

 

First NEVER EVER EVER use an analog meter to check ohms on ANYTHING electronic made in the last 30 years, EVER! Second the tps voltage will change with movement.