click, buzzing, but no start

[Mighty92]

I got a 1992 mighty max 2.4 4g64. The most persistent issue I’ve had was turning it on. I have gotten a new ecu and new starter twice. Ecu clicks on with ignition, small buzzing noise when trying to crank, but no crank. Sometimes I can turn it on, on the first crank, sometimes it’ll take multiple tries, and ive had occasions where it’ll take over 15mins to turn it on (with unplugging battery, unplugging ecu, unplugging starter power). I did receive a fuel pump code, and it went away. I wonder if that could be the problem to my solution. I got a brand new fuel pump unopened. My questions are:

How do I diagnose my fuel pump or confirm that’s the issue?

How do properly replace it? (parts needed, precautions, and trails)

[SubGothius]

No crank would suggest a faulty starter or solenoid, rather than anything to do with the ECU/injection/ignition systems.

One thing you might try to confirm: with the trans in Neutral and parking brake on, connect a test wire to the small terminal on the starter solenoid, and touch the other end to the battery (+) terminal. If that still doesn't crank the starter, the solenoid or starter is bad. If so, it may not be necessary to completely replace it with a new unit. A local alternator exchange or automotive electrical shop can usually rebuild them for a very affordable price.

However, if that test wire does crank the starter, you may have a failing ignition switch.

[Mighty92]

Update:
Tested the starter, and got a crank and start.
Tested the pigtail connector that plugs into the starter solenoid, and it also works.
Getting a new ignition switch, to see if I get a consistent crank.

thanks for the help.