does a 92 blazer s10 4.3 vortec have an air pump and if yes what does it do or is it for

 

My 88 s10 blazer 4x4 2.8 has an air pump. Also called a smog pump. It forces air into exhaust manifold to help burn unburnt fuel. Cleans the emissions. You probably have one. Drivebelt turns the pump. A line goes to a check valve and then goes to the manifold. Mine is on the passenger side of engine. Hope this helps

 

Its actually an A.I.R. pump, Secondary air injection - Wikipedia, the free encyclopedia

 

yours does not have a a.i.r pump. Usually the older pre 90's one have em.

 

some of the 2000 series GMC or Chevy has smog equipment. my 2000 Jimmy has an electric A.I.R. pump kinda sucks when it throws a check engine code.

 

does a bad secondary air pump cause hard starts?

 

No, hard starts could be cause by many things. Timing, fuel, tune up past due, fuel pump, the list is endless. Start with the simple. But brows the forums for more info on hard starts.