Does your 1986 2.9l have a CEL(check engine light)?
If so it will come on with the key ON
And..............if computer is getting a Spark Pulse(PIP), CEL will go OFF when cranking the engine over
If you have a tachometer it should also move up when cranking from the same PIP
If spark is working but out of time CEL will still go OFF and Tach will still go UP, engine just wouldn't start
1986 spark is self contained in the distributor/TFI module and Coil, computer is not involved until AFTER engine starts
You can test if coil is getting 12volts with Key ON
You can test spark wire on coil for spark when cranking, versus spark plug wires, this eliminates Rotor and cap issues
Then test a spark plug wire, if coil had spark
TFI modules were a known issue, new or old, it is what it is
Testing seen here:
https://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml
The Hall effect sensor inside the distributor was more reliable but..............can fail as well, this sensor IS the PIP, it starts the ball rolling for spark
And although RARE................is the distributor turning when you crank the engine over?
Pop the cap look at where rotor is and crank the engine, then check rotor position again, it should, of course, move
The distributor gear can come loose, so distributor shaft no longer spins when engine cranks, so no PIP and no spark
And just FYI, if this happen OIL PUMP is also not working!!! so you DO NOT want a startup
SPOUT, SPark OUT, is used after start up, its the computers control of spark advance, similar to vacuum advance
Its not involved with start up, but engine can stall out AFTER startup if advance is too much
There is a SPOUT connector that needs to be pulled out to disable SPOUT when setting base spark timing, you set base spark timing with engine running, so same as vacuum advance, SPOUT needs to be disabled to do this
After engine is running and WARMED UP, you pull the SPOUT connector out and use a timing light to set base spark timing at 10-12deg BEFORE top dead center(TDC)
Then tighten up distributor and re-install SPOUT connector