Related issues? O2 sensor, low voltage?

[Kheslinga]

A few questions...Tonight I took my car out for the first time in about three weeks. Normally it starts fine after this amount of time.

1. Tonight it did too, however the BAT reading on the Scanmaster was fluctuating between 11.8 and down to about 10.5. After 15 minutes of driving it stayed at about 10.8 and didn't increase (alternator not charging it?) but it didn't drop either. I would expect it too be higher! The headlights seemed a LITTLE dim and The turn signals also flashed very slowly, but overall driveability seemed alright overall. The battery is about 2 years old, but I've never had issues with the battery voltage readings when the car has sat for a while.

2. I had a code 23 (air temp sensor) but I think that is just because I didn't reset the ecm after disconnecting it last time I had started the car. I did however have a new code 45 that started on my way home (about 4 hours after the first drive tonight). At the same time the INT reading was fluctuating between 100 and 115 (rich). Previously it had pretty much been pegged at 128. The BLM readings have been at 105 (rich) for a while.

I realize that this means the O2 sensor is reading rich. Could this be simply a bad O2 sensor (which I've been wondering about for a while) or simply related to low power in the battery? I had also noticed that the CC's were cycling much more slowly.

3. Finally the IAC was reading about 51 while in gear at a stop light, but if I shifted to neutral or park, it dropped back to 31. In gear it would go back to 51 after driving and stopping again. If I got on the gas a little bit while driving, and then stopped it would sometimes drop back to the idle value of 31 that I was getting in park or neutral.

Are any of these problems related? Or does the car have multiple problems? Mainly it's the low battery voltage and code 45/slow cross count that I'm concerned about.

Thoughts, comments and suggestions?

 

[Hacksaw]

You *may* have multiple problems, but you should fix the low voltage problem first of all. Time to take out the alternator. The voltage regulator is built into the alternator.

The slow cycling of the O2 sensor is caused by age. Being cooler wil also affect it some, but if you get a code for it, it's time to replace it. Lead or MMT will shorten the life of the O2 sensor.

The IAC does need to flow a little more air in drive to keep the idle speed even, hence the higher step number. If this is different than the reading you've had before, you can clean it with spray in type products.

-Mike H.

 

[Ttype6]

Are any of these problems related? Or does the car have multiple problems? Mainly it's the low battery voltage and code 45/slow cross count that I'm concerned about.

Thoughts, comments and suggestions?

Your only problem is your voltage.The richness you see is because low voltage = low coil output voltage. You're simply not getting a complete burn. Your o2 is OK. Either the bridge rectifier is bad or the voltage regulator is bad. If you're the kind of guy who likes to fix things yourself I can tell you how to test the rectifier. If the rectifier is good the problem is the regulator. There's now way to test the regulator.

 

[fc227]

It also could be a bad connection at the alternator light. I thought I had a bad alternator, until I checked to see if I had power to the Alternator voltage regulator. And I did not. The contacts on the back of the Speedo cluster Where corroded. I cleaned those. Better than new.

 

[Hacksaw]

Pulling the alternator is first. Clean your battery cables anyhow. Alternator tips at:

http://gnttype.org/techarea/electrical/alt.html

If you still have problems after clearing the ECM, take a look at:

http://gnttype.org/techarea/electrical/grounds.html

-Mike H.

 

[Kheslinga]

Thanks for the tips and ideas everyone.

Ttype 6 - I don't mind doing things myself, but I'm not very mechanically inclined under the hood. If the bridge rectifier or voltage regulator are bad, can they be fixed, or does that mean a new alternator or rebuild is needed, or could the voltage regulator be replaced separately?

This morning when I started the car again, the battery reading was at about 12v (still low). As I drove it started building, but when I stopped at a light it dropped to about 10.8. When I started driving, it would go to about 11.5, but then drop again as soon as I stopped.

I did notice a slight "burning" smell when I parked and got out of the car back at home. Not like gas or oil, but something I hadn't noticed before.

 

[Ttype6]

Thanks for the tips and ideas everyone.

Ttype 6 - I don't mind doing things myself, but I'm not very mechanically inclined under the hood. If the bridge rectifier or voltage regulator are bad, can they be fixed, or does that mean a new alternator or rebuild is needed, or could the voltage regulator be replaced separately?

Both the rectifier and regulator can be replaced separately from each other,but it requires the disassembly of the generator. Technically it is a generator,because it generates electricity. The reason the name alternator is used is because the generator uses A.C.,or alternating current,to generate the electricity.
Auto manufacturers used to use D.C.,or direct current generators to generate electricity . They went to A.C.generators because it provided a steadier voltage. Typically with a D.C.generator the headlights would dim at idle because of the lower voltage output at an idle. So D.C. generators are usually called generators,and A.C.generators are usually called alternators. That's your history lesson for the day. If you don't feel confident taking the generator apart,go to Advance auto and buy one. Again, I could help you through the rebuild. Hopefully the regulator is the problem,because it is easier to replace. Replacing the rectifier requires desoldering and resoldering.

 

[Ttype6]

Low Voltage

Hey,Kheslinga,before you disassemble or replace the generator take it to your local auto parts store and have it tested. Many places offer this service.This way you'll know for shure if the problem is the generator or something in the car.

 

[mybuick]

i had mine rebuilt at morton grove electric on arther av by nw hiway $110.00 . and it was done in a few hours, every parts store had to special order it and it would take a week or 2, and buick can't get them either ... but yah the bulb deal is a common problem now with these cars. my friend just had this problem and cleaned the connector and it was fixed... iam going to have caspers go through my ic in the spring.

 

[Kheslinga]

Thanks!

I'll try getting it tested first to make sure I'm on the right track.

MyBuick - I know about where that place is. Sigh...I'm SUPPOSED to be at Great Lakes on Friday morning/afternoon too.

Ken

 

[Kheslinga]

Solved

Thanks for the help!

I got the charging system tested to rule out the battery and it was confirmed that the alt was barely charging. Then, as it turned out, a friend of a friend who rebuilds alternators in his sleep had one off of an '89 TA. He rebuilt it, came over, and within 15 minutes the new one was on. As soon as I started the engine, I was registering 13.9 volts compared to the 11.5 and under with the old alternator. He showed me on the back where one of the diodes was burned up and had come disconnected.

Feels much better.

 

[Ttype6]

Thanks for the help!

I got the charging system tested to rule out the battery and it was confirmed that the alt was barely charging. Then, as it turned out, a friend of a friend who rebuilds alternators in his sleep had one off of an '89 TA. He rebuilt it, came over, and within 15 minutes the new one was on. As soon as I started the engine, I was registering 13.9 volts compared to the 11.5 and under with the old alternator. He showed me on the back where one of the diodes was burned up and had come disconnected.

Feels much better.

So the rectifier was bad. It's better to know than to guess. It's always good to know a guy like this. I'm glad you posted your good news. So many don't.