2000 Mitsubishi Galant

P_PIRTLE

MEMBER
2000 MITSUBISHI GALANT

Engine Performance problem
2000 Mitsubishi Galant 6 cyl Automatic 80,000 miles

I replaced the battery in my gf's Galant since it was determined that the old battery was no longer holding a charge. I double checked to make sure my connections were secure but not over secure before even closing the hood. I started the car, and it stalled out. I started it again and it ran fine aside from the slight vibration when stopped at a light and low idle, both are problems the car has had since she got a year ago. Today we drove it to school and when we parked I turned off the AC and the engine stalled out smoothly. We got home from our class today and once again, when I put the car in park and turned off the AC, the engine stalled out smoothly as if I turned it off myself. What could be causing this, and could the low RPMs and vibration be related to it?

1 Reply

KHLOW2008

MECHANIC
41,814 POSTS

Hi p_pirtle,

Thank you for the donation.

After disconnecting the battery, the PCM (engine computer) would reset and needs time to relearn. That is one of the reason for the stalling and poor idling.

I would suggest getting the throttle body and Idle Solenoid control valve cleaned.

In the meanwhile, try the following to see if the idling improves.

Start engine without any load, ie, A/C, lights, radio etc all turned OFF.
Let engine run till it warms up and do not rev the engine during this period.
When engine idling stabilises, might take about 15 to 20 minutes of running time, turn the A/C on and let it idle for another 5 mins.

Retest if the engine stalls easily. If engine idling speed is still low, then get the throttle body and ISC cleaned.