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Geeze..... The idle air to fuel mix is too lean. With out Ac on that mix is a tad too lean, but you don't feel it, a EPA BS thing for clean air. With the Ac on that little bit of extra fuel to get a non moving object to be a moving one is all used up, and you need a bit more fuel in that much air.
I am not familar with the car to know if mix is adjustable or not. More or less this is normal.
Jad..... none of the above. I got no idea who told you that, but who ever it was was having some wild fun with you.
No belt driven device is going to lock any crack shaft, not ever. The Ac clutch is lubed for life be it good or bad, and that is a bearing and a electro magnet. I agree to start a cold engine that the AC should be off to allow the best power from the battery to run as little as possible which these days is rather a lot, and to reduce the strain on the battery, start motor and belt driven devices like the AC compressor, which at cold start only wastes power turning yet another compressor which a engine is. An Ac clutch is more or less a press fit these days it has been a century or more since i saw one held with a bolt ot a nut. So long as there is power to it there is little to go wrong. And after a long time the breaings fail and in free wheel mode the clutch hub can chatter.
There is no lubing sealed bearings and the bearing don't turn when AC is on. Because they are locked 1 to 1 with the AC compressor crank.
Turned out to be something stupid - my spark plugs. I was under the impression (from a bunch of Corolla-related forum posts) that my plugs were Iridium plugs straight from the plant, good for 100K miles (as compared to the 80K odd miles I have on the odometer). Turns out that this applied only to Corollas as of 2000 onwards (not my 99 Prizm, which had standard twin side electrode copper plugs). Anyhow, when I pulled my plugs, they looked like the factory plugs (i.e. no anti-seize compound on the threads). I re-gapped the side electrodes on all of my plugs, including the one plug that was way out of spec (>.054, using my wire gauges, as compared to the plug spec of .044), due to center electrode wear. Bottom line, after re-installing the plugs, my hesitation problem went away.
Might be a dumb question, but why didn't you install a set of new spark plugs since you had the old plugs out?
Not at all. I left them in for several reasons. First, the old copper plugs were in good shape - with all electrodes looking slightly-tan (i.e. no fouling) and the central electrodes roughly 70% whole. Second, I wanted to be sure that the hesitation was caused by the expansion of the spark plug gap. Third, I wanted to see if my fuel efficiency (currently ~ 25 mpg) improves just on the strength of the adjustment of these spark plug gaps. After a few weeks of checking my gasoline mileage, I will replace them with new platinum plugs to see the effect of brand new plugs on mileage. It's more of a controlled experiment than anything else.
(I had no problem getting the plugs off, which - combined with the fact that no anti-seize compound was on the plug threads - leads me to believe that they were installed at the factory. If so, Denso twin side electrode copper plugs are pretty darned impressive).
Last edited by Zhang Fei; 08-25-2010 at 12:15 PM..
Basically what I'm saying is that I think your A/C compressor clutch, a component of the A/C compressor, is going bad and might be on its way to 'locking up'. However, it's not quite as serious as it sounds and I'd probably just keep driving until your car is stalling or has difficulty starting. And you might get lucky and never even have these problems.
A little hesitation on an older car is not uncommon.
Basically what I'm saying is that I think your A/C compressor clutch, a component of the A/C compressor, is going bad and might be on its way to 'locking up'. However, it's not quite as serious as it sounds and I'd probably just keep driving until your car is stalling or has difficulty starting. And you might get lucky and never even have these problems.
A little hesitation on an older car is not uncommon.
Thanks for the tip. It turned out to be my spark plugs, one of which was way out of spec (>.054 instead of .044 gap); I learned that I had a misfire problem when the Check Engine Light started flashing intermittently. After I gapped the slightly-worn plugs to spec and re-installed them, the problem went away.
Check the Fuel Filter- Several conditions can cause engine hesitation, one of the most common reasons is a clogged fuel filter not allowing the proper amount of fuel pressure and volume into the fuel injection system. To check for this condition remove the fuel filter and drain excess fuel from the filter, next wipe any excess fuel from the filter. By blowing through the filter you can determine if the filter is clogged, you should be able to blow through it very easily. If you cannot blow through it or it is difficult replace the fuel filter with a new unit and recheck system. Some fuel filters utilize a special release tool available at tool store.
Yes it could very likely be that the A/C compressor clutch is going out or just needs a good lubrication. You don't need to fix this right away but you should keep an eye on it. The worst case scenario is that the clutch with lock up and your car will stall and then not be able to start. It is very unlikely this would happen at speed or even idle, more likely overnight while the engine is off. You just won't be able to start it in the morning because the A/C compressor will lock the crankshaft.
On that car, the compressor shouldn't be too expensive.
Where did you go to tech school? I might go apply for an instructor position, sounds like they need one pretty bad.
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Where did you go to tech school? I might go apply for an instructor position, sounds like they need one pretty bad.
