KIA AVELLA Motor strength problem

Hello everyone:

I have a question. I have a 1999 Kia Avella. I had the alternator serviced, but after the mechanic gave it back to me, the engine lost power, especially going uphill. I'd like to know if anyone can help me with this problem.

Thanks.

Greetings! It's very likely your mechanic had to disconnect the battery to remove the alternator from your vehicle. Doing this erased the learning data stored in the RAM, and then when he reconnected the battery and started the engine, the ECM began operating with all the manufacturer's initial settings, which may not be ideal for the engine's performance in your location. The good news is that the car's ECM "learns" about the conditions under which it's currently operating, and this is a completely automatic process that happens while you're driving. My advice: use your vehicle on a continuous trip of at least an hour, trying to utilize all possible operating variations. First, start it and let it reach normal operating temperature without accelerating or anything. Then, if possible, drive it at a constant speed, using engine braking, then back to constant speed, and finally overtaking. The idea is to expose the engine to all kinds of situations that might occur in normal driving so that the ECM gathers data and adapts the engine's operating parameters to your specific location. After that, you shouldn't have any more problems. I hope this helps.

Very good answer, Alge. You're right, the same thing happens with Toyota vehicles. Just follow your advice and you'll see how your problem is solved. Of course, if you have the means, a diagnostic tool can do it faster.

Actually, while driving today the engine regained power, but at idle the whole car shakes like a diesel. I'm wondering if it's lost its timing? Because before it was revving high and now the engine shakes quite a bit. It's a shame I don't have a tachometer to compare.

Greetings.
That's exactly what happened... the ECM lost its (self-tuning) the moment the battery was disconnected. From what you're telling me, it seems it didn't receive the appropriate information because the idle is low and unstable. It would seem it might need a little more training for everything to return to normal. If possible, remove the air filter and clean it, or replace it if you can. I would even go further and change the fuel filter as well so that the data the ECM collects is more accurate to a properly tuned engine, which might even reduce fuel consumption a bit. Of course, that's what I would do, but I think in your case, just driving it a little more would be enough. Try these ideas and let us know how it goes. We're all here to learn. Regards.