Saturn Repair: SC1 runs poorly when hot with AC on., coolant loss, blue smoke

Question
QUESTION: I've got an SC1 with 140k or so on it, fairly standard scenario, runs great cold, ok warm, lousy with the AC on. The car sputters and hesitates when accelerating, its worst when starting from an idle or low rpm condition, but also noticable on the highway.  Most of the time, the problem can be avoided when starting from a stop by giving it a little gas before releasing the clutch pedal (I don't want to keep doing this though, as I expect it'll help wear the clutch out).  Idle rpm when warm seems a little low too, around 700 rpm.  The check engine light does not come on, and I haven't noticed any coolant loss or unusual smoke from the tailpipe (at 140k it does burn a bit of oil, so there is sometimes a bit of blue smoke, but not much).  I've replaced the ECT and though initially much improved, it still acts up when the gauge gets over half or so.  Yesterday I also noticed that its worse when it initially starts up warm and improves after a few minutes. Though the problem is annoying, its not going to keep me from driving the car, I bought it with 7 miles on it and I'm hoping to make it past 200k.

Thanks,
John

ANSWER: Have you noticed any noise from under the hood. I encountered this once before and it was because the vehicle's A/C compressor was beginning to fail. It lost most of it's oil so when it turned on it lagged the motor down bad. How does the car run without the A/C? Does it still hesitate?

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QUESTION: I haven't noticed any un-usual noise under the hood.  The car does run better with the AC off, but I wouldn't swear that it never has the problem with the AC off.  I tried a couple tanks of premium gas on a long trip today, and that helped a lot - but it did not cure it entirely.  I'm starting to wonder if I've got a cylinder with low compression.

Answer
That very well could be a possibility. Also sometimes the fuel system needs to be flushed professionally. I would have a compression test run and if that is ok, try the professional cleaning which where the car runs off of a special cleaning chemical that is designed to clean the injectors, valves and combustion chamber. A flush like that can be anywhere from $40-$90 depending on the shop. Thanks.