What might be wrong with a 1997 Grand Cherokee that won't idle?

Answer 1

Well, mine does this if my battery has died for longer thatn a few minutes. Keep your foot on the gas and force it to idle, not overreving too much. The computer should wake up after a few minutes. Slowly let your foot off the pedal and see if it will stay on. If it tries to die then keep it on and it should mellow out. ~mac

The idle control rests everytime you start the vehicle.

The computer will not change this setting until the vehicle is started again.

Try this:

On the back of the trottle body is the IAC Valve (Idle Air Control).

These get clogged with carbon and prevent the correct amount of air to enter the throttle body during idle creating the need to hold the gas pedal down to start and manually maintain idle.

These are around $50, but they can be cleaned.

Here's how to save yourself some money.

Remove the IAC by:

1. disconnecting the negative battery terminal (this will prevent any electrical damage and reset the computer).

2. Remove the large rubber hose connecting the air box to the throttle body.

3. Remove the air collector on the top of the throttle body (19mm wrench).

4. Carefully remove the wire harness plug from the valve.

5. Using a T20 torx bit, remove the valve from the back of the throttle body.

Inspect the valve and the "O" ring for signs of obvious damage.

Use either carburetor, or TB cleaner and paper towels to clean the piston tip, sleeve and the socket in the throttle body the valve seats in.

DO NOT TURN OR ROTATE THE PISTON!

Re-install the valve, connect the harness, re-install the air collector and air box tube. Re- connect the battery.

Try starting the vehicle with your feet off the pedals.

I have a 1997 Grand Cherokee. I found out how to do this from another website. l literally just completed this procedure minutes ago with surprising success.

Hope this helps you.