1988 Pontiac Tempest won't relearn idle

LKTREE

MEMBER
1988 PONTIAC

1988 Pontiac Tempest (indentical to Chevy Corsica) with 2.8L and 96,000 miles - after battery disconnect the computer will not relearn idle speed by driving it, and it continues to stall. Took it to the dealer the first time this happened and they successfully did the relearn for $100. What am I missing? $100 to disconnect the battery gets old fast.

Thanks.

2 Replies

LKTREE

MEMBER
3 POSTS

Found the answer myself at another website. There is a specific routine that must be followed (not just "drive the car for a short time."). Here it is, for OBD1 (pre 1996) ECM's like mine:

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1. Reset ECM by pulling ECM fuse (underhood) for a few seconds. (In my case it was dark and I didn't have a fuse map so I just disconnected the neg. Battery terminal for 20 mins. Again.)

2. With A/C turned off, start car and immediately put it in Drive with your foot on the brake. If the car does not start initially, keep trying WITHOUT putting your foot on the accelerator.

3. Let the car idle in gear for at least 5 and no more than 7 minutes.

4. Shut off the car for 10 seconds.

5. Start engine, place in drive and let idle for 5 minutes.

6. Shut off engine.

Idle is learned.

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Seems to have worked well. About 3 mins. Into step 3, the idle surged up and down for about 30 seconds then settled down to a nice idle.

About 3 mins. Into step 5, idle surged again and finally stalled about 4 mins in. Re-started in neutral and let the idle settle down again before shifting back into Drive for about 1 min, and turned it off.

Went for a short drive, then let it idle for a minute in both neutral and Drive - no problems. There ya go.