Have a 94 K1500 5.7 with about 182,000 miles. Recently while driving just suddenly acted like it was out of time. Replaced TPS, IAC, EGR valve and solenoid, new cap and rotor, new plugs, and a view bad vac lines. Sometimes it starts and runs normal, and sometimes it starts and acts like it running on 4 cylinders. No power and will miss if you give it gas. At a loss of what else to check.
Need some help please.
Thanks,

 

When my 93 did this a new distributor fixed it. Something was wrong on the advance.

 

That is probably my next area to try, maybe even a coil. The "sometimes" it what throws me off. Put a new temperature sensor in the block today, so far it has been starting normal.

 

Nope that wasnt it,
Started ok for about 5 times, then back to the same old crap.