I have a 93 with a vortec v-6 cpi it seems that when my blazer gets warm(up to operating temp) it seams to get sluggish and the today another problem occurred driving along at 60mph it just cut off on me. When I took my foot off the gas it started back up. Drove about 1 mile up the road and it cut off again and it started back up after I tookmy foot off the gas just like it did the first time but this time I could not give it any gas without it stalling out it got to the point that it would not even start at all. Had it towed home and when I got home from work it started right up and ran until it warmed up again. The blazer has 193,000 miles on it within the past year I have put a distributor, fuel pump, fuel filter, and a coil on it. What could be my problem?

 

I am a newbie to the forum but an old-hat with old blazers. Two most likely candidates are:
Linear EGR valve sticking open. This has happened to me and has similar symptoms. You will also notice a bad smell (sulfer I think) espcially when starting or idling. This should have led to a SES code flashing at you at some point. You can't test this very easily. I blocked mine off at the manifold to determine this was the "real" problem. This was much easier than the test procedure for this part. There was a recall on this but Chevy limited it to under 75,000 mile engines (they suck!)

You didn't mention replacing the Spider (CPI unit). I doubt this is it because you have 193K miles on it. These usually go out around 100-120K but maybe this is it. This will also have a bad smell but a rich-gas smell. Sometimes this is hard to tell the difference. You can test this easily with a fuel pressure tester. But if you are taking off the plenum top already (to test the EGR valve) you can easily tell if your regulator (CPI part) is bad as there will be a pool of gasoline in the plenum on the right bank side.

Third would be checking your fuel pump again. I am replacing mine this weekend. It is only about 3 years old (40,000 miles) but has become hard to start and only making about 55# and no buzzing noise. This sucks as the fuel pump is so hard to get to. My Toyota Supra had a removable pannel to get at the in-tank pump. Wish Chevy were schmart.

Lastly I would check the vacuum. But this has never happened to any of the blazer motors I have worked on and may confuse you if the EGR is bad (vacuum will also be low without any leaks).

Good luck!