Help from gurus

[TDIDog]

Well I have been having trouble with my alternator over charging, and when I changed it, I noticed a difference in how the car runs. I still have to get the alternator working properly, but, found that before when it was over charging would idle at 650 cold, then 850 once warm. Now after the alternator change around 1000 cold and 1100 warm. no adjustments were made to idle speed. Also notice it would start out better and accelerate with out bog or hesitation. Any explanation? Is 1100 at idle too high for a turbo?
Thanks for all comments.

[ant7]

Originally Posted by TDIDog

Well I have been having trouble with my alternator over charging, and when I changed it, I noticed a difference in how the car runs. I still have to get the alternator working properly, but, found that before when it was over charging would idle at 650 cold, then 850 once warm. Now after the alternator change around 1000 cold and 1100 warm. no adjustments were made to idle speed. Also notice it would start out better and accelerate with out bog or hesitation. Any explanation? Is 1100 at idle too high for a turbo?
Thanks for all comments.

Hi,
There has to be less drag on the engine with the new alternator fitted, that would be the most obvious reason for the engine RPM difference, due mainly to the old altenator trying to continually charge the battery, it must have been similar to the drop you get when you switch on your headlights, or some other heavy current draw item etc.
Hope this helps.

Anthony.

[scarceller]

Constant over charging could have also damaged the battery. How much over charging we talking about? More than 18vdc? If so I'd suspect the battery could also be damaged.

[Joe Bob]

Unless you have a volt meter that is in dash, you probably don't how much over charging the battery was subjected to. Having a load test and testing resting values is about you can do w/o replacing the battery.

As to charging, every alt is different and even will demonstrate different characteristics as to when it gets older, changes a belt, pulley or whatever.

The rule on alts and batteries are....fully charged from an outside source, never rely on the lat to charge up a weak or low battery. It wasn't designed to do so.

Battery voltages should be:
12.5-13v at rest
13v+ at idle
13.5-14ish at 2500 and light and sirens going.

If you have an issue with the alt light going out like I do until you rev it....live with it. I went from a dual pulley to a single pulley and it's just the way it is....

If you don't have a volt meter, well.....I have one, and it's worth more to me than the clock it replaced. I figure my wristwatch and the clock in the radio works better anyways.

The old dash clock makes a good door stop.

More on idle speed change, you could have a minor air intake leak that was caused by your alt R&R.....judicious use of ether will pinpoint the source.

[TDIDog]

I've replaced & fully charged the battery as it was boiled out and toast. Just wondering if the over voltage had an effect on the CIS. I don't think the over charging would place that much drag on the engine, but could be wrong. I've been wrong before! I have to change alternator again, so will check for vac leaks.
Thanks
jack

[Joe Bob]

CIS doesn't have a DME controller. It relies on constant fuel pressure.

[pete3799]

Originally Posted by TDIDog

Well I have been having trouble with my alternator over charging, and when I changed it, I noticed a difference in how the car runs. I still have to get the alternator working properly, but, found that before when it was over charging would idle at 650 cold, then 850 once warm. Now after the alternator change around 1000 cold and 1100 warm. no adjustments were made to idle speed. Also notice it would start out better and accelerate with out bog or hesitation. Any explanation? Is 1100 at idle too high for a turbo?
Thanks for all comments.

Explain this so i understand.
You replaced the alt. and it still doesn't work?
Not charging...... overcharging?

[TDIDog]

The alt was over charging, cooked the battery. I replaced it with a remanufactured, and now does not charge. I need to find out why yet. But am wondering about why it would idle that much higher now after I replaced the alt. I am on vacation at the moment, so can't do any checking or trying.
Thanks

[ant7]

Originally Posted by TDIDog

The alt was over charging, cooked the battery

But am wondering about why it would idle that much higher now after I replaced the alt. I am on vacation at the moment, so can't do any checking or trying.
Thanks

The reason [IMHO] the RPM is high at the moment is i think due to the fact that the replacement unit isn't working' hence its not subjecting the engine to any drag, ie; not charging etc, of course you would see a big difference between the one you took off and this one, as the old one [when it was working] was doing overtime as it was overcharging, now you have gone to one that is doing nothing!
Hope this makes sense, and hope it helps.
A...