Stalling at idle
Thread Starter
|
Junior User
Joined: Mar 2005
Posts: 52
Likes: 0
Stalling at idle
87 Ranger 2.9l, a little history. It's used to haul junk occasionally so I've not been too concerned until this kid totalled my 97 2.3 and I've got to drive the old one 'til I find a new longbed.
Anyways, cold start- cold weather, it was idling high (as per normal) but stumbling and stalling. I replaced air filter, distributor and rotor, and plug wires. The problem got better but didn't go away. Reading recent posts here about the IAC I removed and cleaned it (it was filthy). I soaked it in cleaner overnight and used about fifty Q-tips to get it clean. That made the cold idle smooth, but now after the engine warms and the idle steps down, it stumbles for 45-60 seconds, sometimes stalling, before evening out again to a normal warm idle. During driving (at stoplights) it will periodically enter that stumbling phase and maybe stall. No vaccuum leaks (18" @ idle). Any ideas on what to look at next?
Thanks guys.
Anyways, cold start- cold weather, it was idling high (as per normal) but stumbling and stalling. I replaced air filter, distributor and rotor, and plug wires. The problem got better but didn't go away. Reading recent posts here about the IAC I removed and cleaned it (it was filthy). I soaked it in cleaner overnight and used about fifty Q-tips to get it clean. That made the cold idle smooth, but now after the engine warms and the idle steps down, it stumbles for 45-60 seconds, sometimes stalling, before evening out again to a normal warm idle. During driving (at stoplights) it will periodically enter that stumbling phase and maybe stall. No vaccuum leaks (18" @ idle). Any ideas on what to look at next?
Thanks guys.
Senior User
Joined: Nov 2003
Posts: 478
Likes: 0
From: ut
Check on this forum or the internet for procedures for doing the KOEO and KOER tests on the EEC. I can think of a few possibilities, but they'd just be guesses...Induction air leak, coolant temp sensor, dirty throttle body, bad MAP sensor. Running EEC tests might pinpoint things for you.
Posting Guru
Joined: Dec 2003
Posts: 1,651
Likes: 0
From: Maine
Did you disconnect the battery to reset computer when you cleaned the IAC?
I believe it "learns" to compensate for a sticky IAC and if you clean it without resetting the computer you'll have trouble. I'm not sure if that would be true on an older truck, but it's easy enough that it would be the first thing I'd try.
I believe it "learns" to compensate for a sticky IAC and if you clean it without resetting the computer you'll have trouble. I'm not sure if that would be true on an older truck, but it's easy enough that it would be the first thing I'd try.
Thread Starter
|
Junior User
Joined: Mar 2005
Posts: 52
Likes: 0
Thanks
sjwoody, I think you're probably right, I guess I can take it to Autozone and have them pull the codes. I checked the MAP sensor visually and it was clean clean clean. The throttle body is dirty but operating freely.
john112deere, yes I did, but only for about five minutes. Others here have said 20 minutes or 30 minutes when recommending resetting the comp so it can learn. How long do you think I should leave it disconnected? I did an ohm check across the IAC terminals and read 10.8 on the 200 range, so I think it's good.
Thanks for your responses!
john112deere, yes I did, but only for about five minutes. Others here have said 20 minutes or 30 minutes when recommending resetting the comp so it can learn. How long do you think I should leave it disconnected? I did an ohm check across the IAC terminals and read 10.8 on the 200 range, so I think it's good.
Thanks for your responses!
Senior User
Joined: Nov 2004
Posts: 357
Likes: 0
From: Lancaster, PA
Originally Posted by john112deere
Did you disconnect the battery to reset computer when you cleaned the IAC?
I believe it "learns" to compensate for a sticky IAC and if you clean it without resetting the computer you'll have trouble. I'm not sure if that would be true on an older truck, but it's easy enough that it would be the first thing I'd try.
I believe it "learns" to compensate for a sticky IAC and if you clean it without resetting the computer you'll have trouble. I'm not sure if that would be true on an older truck, but it's easy enough that it would be the first thing I'd try.
Posting Guru
Joined: Dec 2003
Posts: 1,651
Likes: 0
From: Maine
Huh?
I'm no EFI guru, but I've never heard anyone claim that resetting the computer by disconnecting the battery after altering one of the components would cause problems. It won't solve any problems as a stand-alone repair, either, though.
Alto, I tend to disconnect mine for at least 15-30 minutes; usually just disconnect it as the first thing I do, and reconnect it as the last step of the job. I'm not sure what length is the minimum to reset it, though.
I'm no EFI guru, but I've never heard anyone claim that resetting the computer by disconnecting the battery after altering one of the components would cause problems. It won't solve any problems as a stand-alone repair, either, though.
Alto, I tend to disconnect mine for at least 15-30 minutes; usually just disconnect it as the first thing I do, and reconnect it as the last step of the job. I'm not sure what length is the minimum to reset it, though.
