Have had this problem twice myself... here's my totally uneducated opinion of what's happening. On my car, '99 A6 Avant Q w/125k, this "short cycle the night before" problem has occurred twice (both time w/cold outside temps). In both instances, pulling plugs revealed flooded cylinders. The first time, I unplugged the injectors and cranked the engine until it sputtered and fired a bit, then plugged them back in. Car started and ran rough until everything cleared up. Had to reset check engine light from unplugging the injectors though. Second time, I simply held the throttle to the floor (most EFI cars, this stops or greatly reduces fuel flow for a flooded condition) and sure enough, after some extended cranking, it fired up... ran rough for a minute or so... then all was well again. Since then, I have avoided running it for less than 5 minutes after starting and the problem has not reoccurred. My current theory is that the fuel injectors have aged to the point that, when it is extremely cold out, they do not completely seal when the car is not fully warmed up and shut off (leaky). When warm and car is shut off, they seal fine. This would also explain some drop in compression when the car is cold and the injector is leaking, but I can't imagine it would drop it to 10psi. It should appear more like a leaky valve where the pressure bleeds off over time. Anyway, since this is the only symptom and I can control it, I'm not worried for now. If the problem worsens or I can more accurately identify faulty injectors, I may replace the injectors.

Also, FWIW, having done my own timing belt, I can't imagine one in good condition jumping teeth. If the belt had anything even close to proper tension, this would be very difficult without damaging the belt. The teeth are deep and they wrap the cam gears by at least half, if not more, of the teeth. The crank is about a 2/3 wrap... interesting that the shop claims it jumped a 1/2 tooth. I don't understand that either, but perhaps it's just semantics...

HTH,
JJJ

 

this problem sounds very similar to an issue i recently had, where my battery died in the freezing weather (live in NH) and when i jumped it, the throttle was stuck on open, car wouldnt idle right, and had no power

 

guys i used2 work4 honda dealership and this was a common problemn illinoisn the winter ,,here is the cause and i feel that it would also apply2 the audi ,,during cold start up extra fuel is needed2 run just like if a choke was used oncarb engines ,,during warm up a lot of fuel is injected but when shut off beforeeng is warm ,the excess fuel washes the rings and floods the eng ,there fore no compression ,,if spark plugs aren poor shape it will b worse. just my 2 cents

 

It didn't make sense to me either at first. I think what they meant was that because there was low tension, the cam was not in perfect relation with the crank, because there was some slack in the timing belt - about 1/2 tooth.

I just think it's funny that such a sophisticated machine can't be started for brief periods at night. But I guess she's just showing her age.

 

Interesting.... good information, although, at least in my case, the rich condition seems to be the cause of 'no start' rather than lack of compression since I did nothing but stop fuel flow and the engine started. I suppose, in the absence of fuel, some oil could have found its way back to the cylinder wall, but it seems unlikely that the starter created enough oil pressure/movement to get the rings floated again. Curious problem though and interesting that Honda experienced a similar problem.

Thanks
JJJ