01 Toyota corolla 1.8 L 120,000 miles started one day but not the next --wont start - New spark plugs all sparking when engine is cranked. Engine runs great on WD 40 when sprayed into the intake hose through throttle body up to 12 or 1500 RPMs and for 10 or 12 seconds. Removed back seat and fuel pump cover- removed hose clip and removed fuel supply hose from fuel pump. Turned key to run but got no fuel- turned key to crank and fuel squirted up out of pump. Still no fuel at key on position. Replaced hose on fuel pump and replaced back seat. Just for the heck of it plugged code reader in to check for codes - no codes - Just for the heck of it cranked the engine and it started and runs like a champ. Past experience says the last thing you did before it is fixed is likely the thing that was / is at fault. So your best guess - is it the fuel pump or some sort of relay? - is there an on line service manual for this engine? Thanks in advance for your help.

Toyota has an online service manual but you have to pay each time you use it, or pay a flat rate for access during a certain period of time.
Major parts stores usually have manuals for most makes and models.
There may be free sources but I haven't found them.

As best I can find out, the pump doesn't run until the ignition is in the start position. No in just ign. on position.
Is it possible that there was an obstruction in the original hose which you disconnected? I assume that by "replaced" you mean that you put the original hose back on and not "replaced" as in installed a new hose?

If you are certain that there was no obstruction in the hose, the relay is certainly one of the most likely causes. A reasonable cost part to replace to avoid starting problems and/or engine shutdown creating a hazard while driving. Good luck.

It sounds like, to me, you may be experiencing intermittent ECM failure. Frequently, the grounding terminal to the main relay (fuel pump relay) is controlled by the by the ECM. Test the reference voltage going to a key sensor--it is likely a fraction of a volt, instead of 5 volts. My bet is the ECM needs replacing.