Starter / solenoid problems, starts manualy

faulty starter solenoid possibility, if it doesnt start give the starter a tap with a wrench if it starts after that change solenoid or replace starter.

Intermittent electrical problems are the worst to diagnose.
One thing you have not replaced yet is the key switch.
I would run a wire to the starter solenoid terminal that has the wire from the key switch and have a meter ready for the next time it fails to crank.
If you have no voltage on that terminal it may be the key switch. You can also jumper that wire to battery power to see if it will crank by putting power directly to the starter solenoid.
I am assuming the security light is not on when the problem occurs.

There can be one problem among several parts on your car and it involves getting the starting signal to your starter.

Working backwards from the starter there is a starter Solenoid and on some GM products it comes with the new starter. On other setups there is a separate box solenoid which has a main cable from the battery going into it and coming out of it going to the starter.

Either setup has a one or two trigger wires that are small guage. These carry the starter signal from the Safety Interlock and Ignition switch. The Safety Interlock can be connected with a foot on the Brake pedal or clutch pedal depending on the trans,

When the Safety interlock connects, it allows the signal from the Ignition switch(Start position) to reach the starter solenoid and engage the starter.

You could have a bad Ignition switch, Safety Interlock, or starter solenoid. It can be a matter of adjustment of worn parts. You have purchased the expensive parts already.

Its a toss up over which to do first. Vehicles all seem to break at the worst time. If you have time to test the power going to the starter solenoid, the trigger wire, then you can eliminate or confirm a bad solenoid. Then you are faced with why you have a dead trigger wire.

It may only be an adjustment problem or the Ignition switch or Interlock.

I hope my solution helps, please rate my info.

Change the starter solenoid,the contacts may be burnt

Remove it & open it up to see

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Going to need to replace starter solenoid or starter (usually solenoid is no longer available sperately). You can always pull it out and take it to the local parts store for testing.

TIP: Sometimes whacking the starter with a wrench or hammer a couple of times will get it going.

Hope this helps.

What you have done, tune up, fuel filter, wires.

Sounds like a bad starter solenoid, usually cheapest and easiest to replace the starter and solenoid as a unit. It is always best to check for power between the solenoid and the starter with a test light, if the solenoid clicks but the test light doesn't light up you have found the problem in the solenoid.

the safety switch under the clutch pedal is sticking.

Your starter contacts are bad. You have 2 options: Replace the starter assembly, or remove the starter & replace the internal solenoid contacts & the solenoid plunger. This is a common problem with Toyota starters; I replace contacts 3-4 times a week.