1988 Chevy Cheyenne V6 engine cranks but don't start

If it cranks good but won't start, have a helper crank it while you visually check for spark at the spark plugs. If spark everywhere, use a gage and check fuel pressure, for tbi around 9--13 psi.

With tbi fuel injection you should be able to see fuel injection spray pattern, when cranking, anything?

Does the rotor turn when you crank it? Also, check for applicable trouble codes, your obd1, so you should be able to check some codes, yourself. Use a jumper wire at the A & B terminals at the data link connector. Turn key just till the dash lites come on, no further, then the mil on the dash starts flashing, you count the flashes to get the codes. Your looking for two digit codes.

Sorry about that.
I'm talking about distributor rotor. Remove the distributor cap, have helper crank engine while you visually watch the rotor turn. If it doesn't turn, have to check timing chain, then go from there.