what would be the best way to go about starting a 1990 4 cyl chevy cavalier efi that has not been running for several years
First thing I’d do is remove the spark plugs and put some oil directly into the cylinders, then turn the engine by hand several times to lubricate the cylinder walls and prevent scuffing. If the gas has been sitting in the tank all this time without a stabilizer additive, you might have some trouble getting the engine to fire. Filling it with fresh gas is a good idea. You also need to check if the battery is charged…odds are it will need to be replaced.
Make sure it’s got enough oil in the crankcase, and then give it a go. It will probably run rough and smoke at first, but this should clear up as oil gets flowing and the fuel lines clear themselves out.
I would add a change of brake fluid as it likely has absorbed moisture, and if the parking brake has been on it likely will be stuck an if it has not the cable may well be rusted. Do all the standard maintenance items that may have come due during that time like oil changes new plug wires timing belt if so equipped etc. (note most things like timing belts and oil have both a time and miles change interval. You do which ever comes first.
Where was it stored during this time and how wet and damp is/was it?.
I would remove the old oil and replace it (filter too). Check the old oil for signs of water.
Battery is dead I assume, so replace that, and make sure the terminals are cleaned of completely of accumulated acid crud. Remove the spark plugs and squirt oil in the plug hole when the piston has been moced to BDC, so you can get the oil onto the bore, not the top of the piston. (you’ll need new plugs, cap and rotor anyway, but later.)
What is it Carb or EFI? if EFI, remove the fuel pump fuse for the moment, you’ll not need it.
Timing belt or chain and a belt, when changed last. I’m not sure of the effect on a belt of having it in a fixed position in the cold for years on end, cannot be good I suspect.
Check the intake for mice, birds, spiders, etc and clear all that tubing out. A new air filter may be a required, but later.
Check the exhaust for vermin also.
For now all we need to do is check the compression. NO point in investing in anything if the valves and bores have become all rusted and pitted.
Connect another running cat to the battery so as to recharg it.
So with the liners wet, spin up the old engine till the oil light goes out and check the compression. it that is bad, no point in going any further.
If it is OK, then
Plugs, Cap Rotor,
Empty the gas tank and if EFI use the EFI pump itself to pump out all the gas in the lines. You might also add Inj cleaner to the new gas.
A good per-start workout for the pump also.
complete all repairs prior to inserting the spark plugs.
Heat the spark plugs and insert them last. (only reason for that is to help evaporate any wet gas and make ignition a little easier.)
Then try to start it. Assuming it does start watch out for backfires, so no heads over the carbs.
Also check the exhaust is clear.
And watch the coolant temp, your thermostat may have seized also. If in the mood, change it before starting.
Check all the belts for frozen in bends and cracks on the inside, change as necessary.
Good luck.