Return of bad symptom
 

Some of you may remember last year after I bought my VX I had a lingering idle problem. The symptom was that right after I'd shift the idle would go up slightly--hang out--and then slowly drop down again instead of dropping immediately. Well, recently I had the alternator replaced, the water pump replaced and the valve cover gasket replaced by a new mechanic and the idle problem came back!!

Now this doesn't make sense to me.

The way the idle problem was fixed the first time was by cleaning out the throttle body. Is it possible my mechanic somehow fouled up the throttle body while doing the above described repairs? Any ideas? I am going to speak to him today. The symptoms were immediately evident as I drove out of the mechanic's garage.
Thanks,
Jason

P.S.
I forgot one other thing. The alternator belt was also replaced and now makes an ever so faint squealing noise after I start the car up. My car has never made a squeaky or squeal noise from a belt. Not sure if this could have any bearing on the issue.

That sounds like the belt tensioner wasn't adjusted appropriately after the belt was replaced and now its slipping somewhere on its path(assuming that it is serpentine). That may also explain the idle as it removes/puts a load on the engine as the belt grips and slips. Or I could be absolutely crazy and its something else. I'll think about it a while longer.
Now that I think of it wouldn't a compression problem cause erratic idle? Such as not cleaning the head surface when replacing the gasket or if there was an uneven surface where a gap has appeared, but you would see a noticable difference in the engine at that point such as burning oil, or oil squirting/shooting out of the gap.
Heres another one, if you use an oil based air filter; clean the maf sensor with carb cleaner, any excess oil has clogged the sensor.

The battery light came on driving home. The same thing happened before the car was diagnosed with a bad alternator before I brought it in. And it's making the whirring noise again that it was making before when battery light was on last time. So my alternator went bad again!?!? The mechanic did say to stop EOCing--and I didn't... but I don't see how it could fry the alternator so quickly as I have only driven the car 3 days since its repair and have been EOCing all summer long.

You have to either have a main fuse going out somewhere or you connections to the alternator are in poor conditions causing an incomplete current. Or you have an electrical drain somewhere causing the alternator to work excessively and this would have to be one hell of a drain to kill it in three days.

edit: the maf sensor can still be the culpret, I think if it gets inadequate or too much voltage it sets off the battery light. In this case you would have to replace it.

This doesn't sound related to a problem I had with my (sold 1.5 years ago) '95 VX, but I'll throw it out there anyway. My VX had about 200,000 miles on it, and it suddenly began to have problems starting. Only a click, nothing else. I thought it was a bad starter, so I installed a new one. Problem continued, so I brought it to a mechanic and he found the main ground wire was corroded. This wire can be found on the front passenger side of the engine and is connected to the frame on that side. It was likely corroded from the salty New England roads in the winter. You should check yours because bad grounds can cause a host of funky issues.

And by the way, I did engine off coasting for the entire 225,000 miles that I owned my VX. Bought brand new in Novemebr 1995 and replaced one battery and one alternator in September 2001 when the car had about 140,000 miles on it. That's pretty good life from a battery. My mechanic said the weak battery probably brought the alternator down with it. No disrespect to your mechanic, but there's no possible way EOC does any harm to the alternator.

I didn't want to be the first to say it but go to another mechanic because it sounds like he knows theres another problem and is just blaming it on eoc instead of fixing the real problem.

My battery was run down before the battery light starting coming on (so I could have worn down the alternator by driving around with a very low battery not letting it recharge with my excessive EOC) but this time indicates to me it's (an)other problem(s). Thanks guys, you've been very helpful.

If the belt is squeeking a lot, and is very loose, then it could make it so the alternator isn't spinning as much as it should.

If you have a weak battery or weak alternator, sometimes it is difficult to figure out what is wrong. Make sure the connections are clean on your battery and the cables for it, and the ground cables for your motor are in good shape.

You could have a sticking throttle body again. I would just try some throttle body cleaner to see if the problem goes away with that. I had the same issue with my old and smoking 240k mile vx motor.

the tach was behaving flawlessly before---sticking throttle body seems like a problem that would occur gradually over time rather than suddenly after a repair ;) battery is new so those connections are good. Dunno about the ground cables tho.

I'm sorry man, you're obviously knowledgeable about cars but you know nothing of Hondas. His Civic doesn't have a serpentine belt. The only tensioner is on the timing belt. The AC, alternator, PS etc are all on "accessory" belts. His Civic doesn't have a MAF sensor, it's a speed density system. DO NOT shoot carb cleaner or any other cleaner into the MAP sensor.

A squeal noise after you change the alternator indicates that the alternator belt wasn't tightened properly. Loosen the nut, pry back the alternator as hard as you can, then tighten the nut. Also, it is extremely common for mechanics to forget to put the nut on the lower pivot bolt on Hondas. I can almost guarantee you that it's not there.

As for Idle, Idle problems are extremely common on 92-95 Civics. Seek out the all-encompassing idle fluctuation thread over at Honda-Tech.