Speedometer and tach jumping

[worldtv]

I have a 2002 pt cruiser,88,000 miles. It is Intermittantly having a problem, the engine will start idleing high, and the speedometer, and tach will start jumping around, This usually happens at idle, at a stop or in park. Most of the time if you tap the throttle a few times, the gauges start acting normal again and the idle also goes back to normal.

I was wondering if anyone had any ideas, and Thanks in advance...

[CREWZIN]

Welcome to the forum.

How come hardly anybody joins the forum BEFORE they have problems?

Anyway, my guess it that your IAC (Idle Air Controller) is either dirty or bad. You can take it off and try and clean it to see if that help. It's located in the back of the throttle body. See picture.

[worldtv]

Thanks for the suggestion, but would that cause the tach and speedo to act crazy?

And I just got the PT a few days ago, have never had one before, so had no reason to be in the forum...........

[CREWZIN]

Originally Posted by worldtv

Thanks for the suggestion, but would that cause the tach and speedo to act crazy?

And I just got the PT a few days ago, have never had one before, so had no reason to be in the forum...........

Good answer. I was just sort of talking to myself out loud. We get about 3 to 5 people a day with their first posting and it's usually some sort of problem.

Anyway, If the idle is erratic (going up and down) the speedo and tach will follow along with the revs of the engine. Now if the tach is jumping all over the place not in time with the revs of the engine and the speedo is doing the same, forget the IAC because you probably have an electrical problem.

[worldtv]

That is exactly what is happening, the speedo will jump around from 50, 60,90, even peg out, back and forth, sitting in park, and at the same time the tach is jumping all over the place, but not with the engine speed, even though the engine speed does go really high.

I really want to thank you for your responses. I just cant figure out what is in common with the speedo, tach, and engine reving.....

Its quite the mystery for me and my little pee brain.

[CREWZIN]

Here's a little something you can try, although I don't what it will prove. It's a way of testing all the guages in the three dials.

There's a little button on the dash that will reset your trip meter. Hold it in, then turn the key to the ON position without starting the engine. The numbers in the center dial will start counting (then let go of the button) and then all the needles on all the dials will go from low to middle to high.