2003 toyota avalon no injector pulse at time

Car came in as a crank no start. Found we have spark but no injector pulse or it will pulse once and stop. No codes. No security light flashing it works as it should. Car will randomly start and runs great when running. We have constant 12v at injector during no start but pcm is not grounding. Tested all power and grounds to pcm all ok. Sent pcm in to be tested it also showed good. It seems like if you turn key on and leave it set for about 10 seconds that it will start almost everytime. i see no information on testing the security system through our repair info. it seems like the security is my problem but no codes and no flashing light. have scoped cam and crank signals as well all looks good. is there a way to test the immobilizer in pcm?

Maybe try another key?

Not sure there's a way to test the immobilizer directly, other than check for codes and the dash light (which you've already done).

Might be worthwhile to have a quick look at scan data before you try to start it next time. Do the ECT and IAT match after sitting overnight? Is the MAF rational?

we tried all keys with car same out come. everthing looks normal on scan data. if you turn key on and leave it for around 10 seconds car fires right up. if you try to crank it right away its a no start. same way if you have it running and shut it off it will not restart untill you pull key out of ignition and put it back in

Typically an immobilizer system will NOT be active immediately after closing the switch but will be sleeping for at least 3 to 5 seconds. Only after that period of time the control unit looks again for an authorized key.

So if the engine is shut off and stays off when only turning the key off for half a second or so it might be something different/more than immobilizer.