Evinrude 50 4 stroke 1999 been setting, need to restart suggestions/ guidence

Evinrude 50hp 4 stroke (Suzuki)1999, had issues with many years ago #3 cyl, mis sfire and cold temp compared to other cylinders, and shoved it to the back of yard till I got time to play with it, now semi retired, it needs to go scrap or repaired and replace my 35hp 2 stroke on the back of my other pontoon boat.
Last week, With no fuel, fogged cylinders, let set for 20 min, ran compression test 1: 60-195, 2: 60-195, 3: 60-180, not perfect, not overly bad, will live with.
Previously had to Suzuki shop 2x said no issue ran their computer, 2nd time said bad cam sensor, replaced no help,
IN THE PAST
I've swapped coils, replaced coils, plugs, swapped injectors, replaced secondary fuel pump electrical failure), all to no avail, thinking it was probably a bad computer, and it still may be, but I'm going to start the testing over, since the compression is still good. I'm going to do some further testing to scrap or save.

I'm open to any suggestions or ideas. sorry to be so long, just trying to answer all questions in advance.
Things I'm going to do:
pull elec fuel pump and clean well and all area.
Clean and flush with cleaner and air all fuel lines, tank and all fresh fuel.
Pull all injectors and make sure screens are clean, can soak in carb cleaner if that is suggested and safe.
Is there a way to safely test the Injectors for flow?
There is no corrosion on the ECU pins.
I have a noid light to test Inj signal.
I have a spark tester that I can test for a large spark
Any rotation will be done with water on to save water pump.
Will pull and replace water pump impeller if all tests are good
Replace fuel filter on side.
Should I replace the fuel filter inside of the fuel pump or clean and reinstall?
Of course oil and filter change before any further testing.
Change lower unit oil with water pump
Estimate time on this engine is less than 100 hours, I knew the couple that had it since new.
Any other Ideas or suggestion missed items, would be greatly appreciated.
Thanks again in Advance for them,
Rick in Ga

first thing is to get a manual and compare results to specs. it may flag a problem more than swapping or guessing but... ex: see sect 3.59 on injector electricaland physical tests and..NOID lamp checks
download this manual



pull elec fuel pump and clean well and all area. (measure ohms on pump)
Clean and flush with cleaner and air all fuel lines, tank and all fresh fuel.
Pull all injectors and make sure screens are clean, can soak in carb cleaner if that is suggested and safe. (Measure ohms per injector.. if OPEN-JUNK check that injectors click "no click ? try cleaning " ) see utubes on inj. work u could do but professionnal inj. jobs are best)
Is there a way to safely test the Injectors for flow? see utubes couple of videos showing basic flushing)
There is no corrosion on the ECU pins. (Check & apply contact cleaner check ALL connection points incl. connectors at both end of inj, coils, pump etc... "many years" sitting is a long time !)
I have a noid light to test Inj signal. (report findings here)
I have a spark tester that I can test for a large spark (report findings here)
Any rotation will be done with water on to save water pump.
Will pull and replace water pump impeller if all tests are good (replace anyway)
Replace fuel filter on side. ok
Should I replace the fuel filter inside of the fuel pump or clean and reinstall? cleaning filtersshould do
Of course oil and filter change before any further testing. OK
Change lower unit oil with water pump (replace anyway)
Estimate time on this engine is less than 100 hours, I knew the couple that had it since new. (should be able bring it to life...if nothing major)
Any other Ideas or suggestion missed items, would be greatly appreciated.
(easy stuff first...)