My 04 cavalier wont start i have good spark good compression and 40 psi of fuel pressure it will run on starting fluid and i i hold the pedal to the floor it will run for a second. I removed the plugs and they were wet. i thought it was bad gas so i drained it and added fresh gas that didnt help. any ideas

That is not bad compression, you have something else wrong. IS the fuel good? What is the timing?

a oil gauge reading maybe delayed until car starts and builds good oil press.Did you check for spark
was car running good before this happened? Do you have a rpm reading when cranking car?

sounds to me that the ecm is not telling the injectors to fire. is the check engine light on? if so, have the codes read.

when you say good fuel pressure is it 55 psi with the key on and engine off? any thing less then 50 psi will not start the engine. if the engine starts with starter fluid then the problem is in the fuel system.

Check for fuel pressure, 2.5 is Key on engine running
13 PSI (Pounds per Square Inch)

3.3 engine is 40-47 PSI (Pounds per Square Inch) Key on engine off
31-44 PSI (Pounds per Square Inch) Key on engine running

If this truck has the 4.3L vortec motor it will not start with 40-45 PSI fuel Pressure.Thius engine requires approx. 56 PSI fuel pressure or it will not start. The fuel pump more than likely needs to be replaced this is a common problem with the 4.3L vortec engine.Change the fuel pump and your problems will be solved.

check for fuel pressure in the injection rail

check your crankshaft position sensor

i would check the cap and rotor if it has spark and 40 lbs of fuel pressure if cap and rotor are ok check for injector pulse thats the only other thing it can be

Engine Cranks But Will Not Start

For an engine to run, you need three things to happen inside the engine. Compression, fuel and ignition, without any one of these components the engine will not run.
Basic Checks:

A. Test Fuses. Test both under hood power distribution center and the fuse panel under dash. This is done with a test light tool. The test light should illuminate on both sides of the fuse, if not the fuse has failed and needs to be replaced.
B. Testing Fuel Pressure Test for proper fuel pressure with a test gauge on the fuel rail, most throttle body injection cars (TBI) are between 13 psi and 17 psi. and most (DPI) direct port inject systems are between 40 psi and 55 psi. If no or little fuel pressure is observed and there is 12 volt power present the fuel pump, the fuel pump needs replacing.
C. Checking Timing Belt Test for compression by removing a spark plug and insert a compression gauge. Crank the engine over about 5 seconds the gauge should read between 125 psi and 165 psi, if no compression is observed remove front engine cover to inspect timing belt or chain. Crank engine to observe cam rotation, if the cam does not rotate the timing belt or chain has failed. (note: if the timing belt drives the water pump it is best to replace the water pump at this time)
D. Test for Injector Pulse Remove injector connector to insert injector test light (node) or volt meter. Observe light flash or gauge pulse while cranking. If light/voltmeter doesn't respond, an ignition distributor/crank angle sensor (CKS) or an ignition module is most likely your problem.
E. Test for Ignition Spark Remove spark plug wire, insert an extra spark plug into end of wire, rest spark plug next to a ground source then crank engine. You should observe a blue spark between the spark plug gap and ground source. If no spark is observed, an ignition coil, ignition rotor or spark plug wires might have failed. (always keep hands away from engine when cranking)