Its that time again of the year for the dreaded no start from no compression to plague some of you Geo owners. This is only a 3 cylinder engine problem with hydraulic lifters.
There are two options for this problem one is the temperature outside has fallen and a few degrees and the oil in the engine has thickened raising the oil pressure at the oil pump because the oil pressure relief valve is sticking or the spring is not holding the correct tension any more.
The other option is its if its not cold related the pressure relief spring has changed tension or the oil relief piston has debris in it causing it to stick.
The fix for any issue is the same remove and replace the oil pump.
Your systems will be the car cranks over and possibly try's to start but maybe just cranks over. it sounds like it is cranking over correctly but then it spins faster than normal and acts more like a broken timing belt. If you were to walk away from the car for 20 minutes in the summer at 70f it will bleed off the excessive oil pressure and volume in the lifters and you can repeat the process over and over. if its cold weather related you may have to wait over night or the oil is so cold and thick the problem will be there all the time.
Diagnosing the problem is as easy as cranking it over tell it sounds like it has no compression or its spinning free like a broken timing belt. Simply and quickly remove the spark plugs and check the compression to see its virtually 0 psi.
now to confirm this install a oil pressure gauge and check to see that when the problem exists it has roughly and usually more than 59 psi. make sure this gauge is accurate or you will chase your tail. I will from years of experience tell you oil pressure testing gauges and compression testing gauges are almost always off a bit.
This is a Geo only problem and a 3 cylinder at that issue only. many or lets say almost all no geo techs will and have condemned every single one of these engines when all they needed was a oil pump installed. I cant tell you how many Geo owners in the Midwest and east coast have told me over the years that just thought the 3 cylinders were cold blooded and they just didn't drive them in the winter. Come spring it was the best car ever.
What is happening here is that the oil feed line down the front of the head that feeds the cam and lifters goes directly to the side of the hydraulic lifters bore right at the point it is taking in the oil during normal operation. What your experiencing is this excess volume/pressure being more than can escape around the lifters bored hole which would normally just be leaked out and drained back to the oil pan. Your oil pump with its extra pressure is actually able to pressurize the lifter and force it open which is pushing the valve's open so that they can never close creating 0 zero compression issue. After you walk away from the geo and let it set a while the lifter bleeds off and will seem to have compression on the next start tell the pressure rises high enough to cause this issue to happen again.
I hope this helps.