alternator, battery, idle problem???

[trxeslr66]

I have been having a low idle and CEL for the IACV for 6 moonths. I replaced the IACV and had everything the air intake including the TB and TPS voltage checked. I cant find a cause with a mechanical defect in the engine for the low idle and CEL. When I say low idle I mean 250-450 RPMS when it should be 600-700 RPMS. I have verified with a code reader the idle gets as low as 250rpms. So due to recent battery problems I suspect the low idle may be a electrical issue of some sort. Over the winter I thought the low idle was worse under a load(heater + stereo, subs, amp). Now that summer is here I feel the same way with the A/C load. But during the past 2 months, it has gotten significantly worse. It got so low that it stalled 2 times in 1 week. And for these stalls it was because the battery was dead. So I deal with it after the first stall by jumping it, but after the 2nd I jump it then go to sears and they test charging system and battery and say the battery is bad. So I get a new battery under warranty and the idle is better – closer to 600 now which is the lower end of a normal idle. So I think back... The problem started last October, I had to get a new battery in January AND yesterday. There is the same amount of months in between. One more fact: the CEL for the IACV come on at idle AND when the automatic transmission is downshifting on the interstate. When the car downshifts, the load coming from the charging system would change for a second. I think think there is a defect in the charging system causing the batterys to go bad and cause the CEL due to a low and or fluxuating load. The alternator was rebuilt 1.5 years ago. So when the battery progressivly goes bad and hold less and less of a charge, my idle gets crappier and crappier. Any ideas what is causing the problem??

[lmdew]

What did they say about the Alt when you had it checked?

 

I'd check the alt to make sure its good. A bad alt could be causing the problems. How's the temp of the alt when its operating? I will be warm, but should not be so hot it burns you.

 

If you need an alt, let me know. I have some good used ones.

[Bill90Loyale]

I'd be tempted to double-check the air intake, particularly a one or two inch diameter black hose sort of at the bottom engine side of the air filter box. That hose can become loosened or disconnected, especially when changing the air filter. Can cause idle and no-start problems due to vacuum leak.

[Cougar]

Along with checking the alternator clean the battery connections and check the wiring to the alternator for problems, including the fusible link.

[Sweden]

Are you sure that you have the correct alternator? Does the vehicle idle 'pulse'? I had some real issues last summer with idling last summer/fall when the incorrect alternator (Japanese OBW version) was installed in my Indiana-built OBW. You can search for these posts under Sweden if you think this may be the issue. Alterantors have different 'set points' which cause them to act differently even though you can't tell on the meters. If you feel that this might be an issue, swap the alternator with another and see if the problem clears up.

 

Just a thought based on three months of hell that I had...

 

Good luck

 

Sweden

[Lawsonmh15]

I have been having a low idle and CEL for the IACV for 6 moonths. I replaced the IACV and had everything the air intake including the TB and TPS voltage checked. I cant find a cause with a mechanical defect in the engine for the low idle and CEL. When I say low idle I mean 250-450 RPMS when it should be 600-700 RPMS. I have verified with a code reader the idle gets as low as 250rpms. So due to recent battery problems I suspect the low idle may be a electrical issue of some sort. Over the winter I thought the low idle was worse under a load(heater + stereo, subs, amp). Now that summer is here I feel the same way with the A/C load. But during the past 2 months, it has gotten significantly worse. It got so low that it stalled 2 times in 1 week. And for these stalls it was because the battery was dead. So I deal with it after the first stall by jumping it, but after the 2nd I jump it then go to sears and they test charging system and battery and say the battery is bad. So I get a new battery under warranty and the idle is better – closer to 600 now which is the lower end of a normal idle. So I think back... The problem started last October, I had to get a new battery in January AND yesterday. There is the same amount of months in between. One more fact: the CEL for the IACV come on at idle AND when the automatic transmission is downshifting on the interstate. When the car downshifts, the load coming from the charging system would change for a second. I think think there is a defect in the charging system causing the batterys to go bad and cause the CEL due to a low and or fluxuating load. The alternator was rebuilt 1.5 years ago. So when the battery progressivly goes bad and hold less and less of a charge, my idle gets crappier and crappier. Any ideas what is causing the problem??

 

I gotta believe it's either the Alt, or a short. Check for any loose connections. You may also want to test your coil pack and ignition. Let me know if you need the procedure for testing your coil pack.

[nipper]

You have a bum altenator. A Shorted battery can cause an altenator to go bad. Not all rebuilds are the same, some are crap. I would try another altenator.

 

nipper