'89 Blazer won't start

A friends '89 Blazer (4.3l engine) recently failed to start. I've looked at it, and have determined the fuel system seems okay. I can hear the pump run, and can see fuel squirt into the throttle body. There is no spark at the plug wires, so I started by replacing the old, crusty distributor cap and rotor. No difference. My next move was going to be replacing what looks to be the original coil. If that doesn't work, my next thought would be the ECM.

Any other thoughts or suggestions? I appreciate all the help.

The DIY method saves you money only when you diagnose the problem correctly. Throwing parts at it will eventually fix the problem, but at a cost. The ECM is a very substantial part and rarely needs replacement. It also carries with it a substantial price tag. Replacement should only be done after diagnostics confirm it is faulty.

Does the distributor shaft rotate when cranking the engine?
Are the plug wires good?
Does the ignition coil produce spark?
Disconnect the EST connector and shoot a timing light at the damper while cranking, you should be able to see if the ignition timing is close/ok.
Post your results.

I had a similar problem with no spark. Replaced the coil, nothing. Had it down to either the ignition control module, or I think the pickup or something on the dizzy. I just ended up replacing the hole distributor and that solved my issue.

Well it turned out to simply be a bad coil. Installed a new one, and it fired right up. It looked like the original part, very old.

Glad you got her going! Thanks for posting your results.