what could it be

92 jimmy  4.3 vortec cpi    start but missing manifold on passager side is warm driver side is hot  spark plugs and passager is flooded hoses to the brake booster uplug it runs  plug it back in and doesn't run or runs rough

Leaking CPI fuel pressure regulator?  Check your fuel pressure, I am sure you will find that it bleeds down after you turn the key off.  Next step would be to pull off the upper plenum and pressurize the system again, inspecting for the actual leak location.  If you see puddles of fuel on the passenger side of the lower intake, then you have an FPR problem.  This is what I am suspecting is what has happened with your engine.

This is a common problem with the CPI motors and has been well documented on the site.  Please run a search with CPI, FPR, or some combination of keywords that makes sense and you should find more than enough information.

just put a new cpi on and still having the problem

When you did the CPI unit, did you replace the internal fuel lines?  Test the pressure just to make sure that it still isn't a bad FPR...

getting good pressure no gas in the plemun the fpr  came with the cpi unit   but before i bought the cpi unit  i bought  a fpr so now i have 2 new fpr  one gas hose we replaced  we also replaced about 5 other sensor  o2,water sensor,map,trottle body,2 relay new plugs,wires,  cap button ,  the sensor on the distr.  the  pcv valve ,new fuel filter  changed the oil twice  because of gas getting down in oil  took the egr off and made sure that was clean checked the timing  number 4 was not hitting all the time but the others were  checked the fuses replaced the vac hoses we found were bad new muffler took the cat off
 
 
we just don't know what else to do

You say that the pressure is good.  What is it holding at with the key on, engine off, pump primed (specific pressure reading) and what happens to it when you turn the key off?  What is the pressure right after you turn the key off, after 10 seconds, 30 seconds, 1 minute, 5 minutes, 15 minutes, & 30 minutes?  I'm sorry if it sounds like I am beating a dead horse, but too many times people make comments that the pressure is good when in fact there is a problem...  I am only asking for information that I would get myself if I were working on the vehicle.

So by gas hose, you mean one of the fuel lines inside the engine?  These typically come paired and should be replaced as such.  Whenever the CPI unit is removed, these internal fuel lines should be replaced (unless they are fairly new - ie. less than 1 year of operation).

one of the gas hoses were cracked and we replaced the hose   we then put the spider in and hooked everything up and made sure there was no leaks turned the key on   the pressure  is around 55 to 60 with teh key on then goes to about 63 when starting       if it doesn't start   we  unplug the fuel pump  try to start it   starts then dies shortly after   then plug the pump back in  and the car starts      i guess it burns some of the gas off  enought of start    we  had someone else look at it  that knows this type of engine   and  he says  he doesn't know either    going to put it on the computer next  and see if  anything came ups