1994 Ford Escort engine idle erraatic

JWDS2003

MEMBER
1994 FORD ESCORT
4 CYL
2WD
MANUAL
11,300 MILES

Last night my almost new expensive battery was stolen from my car because I accidently left the door unlocked and I do not have a driveway and must park on the street. So I bought a cheap battery today at Sears (49.99). Now when I warm the car to let the idle go down, it reaches a spot and then drops suddenly. Then the idle goes back and forth from low to very low to low to very low, etc. My husband says the thief may have pulled so hard on the wires that something happened there. I am wondering if it may be the cheap battery problem. The Sears rep. Said this battery is correct for my car. It does have a 5-yr warranty. I just now drove the car and it seems to drive just like before and the blinkers and wipers work just like before. It is the idle that is very different. Your advice is appreciated.

1 Reply

BMRFIXIT

MECHANIC
19,053 POSTS

Computers may require a relearn procedure after the vehicle battery is disconnected. Vehicle computers memorize and store vehicle operation patterns for optimum driveability and performance. When the vehicle battery is disconnected, this memory is lost. Default data is used until new data from each key start is stored. As the computer restores its memory from each new key start, driveability is restored.
Driveability problems may occur during the relearn stage. Depending on the vehicle and how it is equipped, the following driveability problems may exist:
Rough or unstable idle.
Hesitation or stumble.
Rich or lean running.
Poor fuel mileage.
Harsh or poor transmission shift quality.
To accelerate relearn process after battery removal and installation, vehicle should be road tested in the following manner:
Vehicle at normal operating temperature (cooling fan cycles).
Accelerate at normal throttle position (20-50%).
Cruise at light to medium throttle.
Decelerate to a stop, downshifting and using brakes normally