stumped with 8.1 Vortec issue

[Cam-Shaft]

Hello Gents,

Recently purchased a '91 K5 blazer that was repowered with a 8.1. Overall it runs great and I'm quite pleased with the rig however there is an issue that I cannot seem to track down.

Usually when cold, it starts right up no issues and idles normally. When warm it will often start but idle very low, almost not running at all and when you press the accelerator there is no response at all. The Compushift unit shows that the TPS is working and when I took off the air filter, I can see the intake manifold moving properly.

My fix is usually to shut it off and try again, and usually 10-15 times later it will start and idle normally with the accelerator working again. I am trying to figure out what the correlation is between the low rough idle and the lack of throttle control....

I recently replaced the battery/alternator (problem happened before) and yesterday replaced the MAF sensor as it seemed to fit the problem description.

Warm engine - low idle - no throttle response whatsoever....

Thoughts? Thanks in advance.