1993 Chevy Blazer 93 S 10 Blazer with the infamous CPI

I have a 93 Blazer with the 4.3 CPI and I have not had any trouble with it since I got it 6 years ago. Recently the vehicle sat for over a year and then the first time it was drove after that was a 850 mile trip where I got 25 miles to the gallon, I did the normal things to try to make sure it would make the trip changed the oil, air filter, checked the air pressure and all that good stuff. I went from ND where the altitude was around 1,000 ft. When I got to where I was going I am now at almost 7,000 ft. It ran like a top for the long drive and for the first two days here but all of a sudden it started running really rough at idle only. When there is pressure on the gas pedal it seems to run fine but as soon as I let off it starts to spit and miss and sometimes it dies when it dies there is no starting it until I unhook the battery and let the computer reset. I got a error code saying that it was the map sensor so I replaced that and nothing changed now it is giving me an error code of 32 which from the book that I used there is no code 32 for this vehicle I took the motor apart to look at the injector and plastic fuel lines to see if there was a leak or anything inside the engine and there was a little gas sitting in there. Then I turned the key on to prime the system to see if there was a leak while under pressure but there was nothing I cleaned it out and tried it again and there was no gas in there the next thing I was thinking of replacing is the egr valve but that part is kind of spendy for this motor and I would like to stay away from replacing parts I dont have to. If there is anyone who has had similar problems or anything like this happen and know what might be wrong with it please help me I love the vehicle and do not want to get rid of it. It also does loose vacuum sometimes while driving but that comes and goes Please Help Me!