98 Chevy Blazer 4.3 liter vortec starts, but won't stay running.
 

I had a 2000 Chevy Blazer with a blown motor, I took out the trans and transfer case and put them into this 98 I bought with a bad transmition. The 98 ran before I did all this work. I also swapped out the 2000's fuel pump which was a year old, and put a new fuel filter in line, in the 98.The fuel line ruptured so I put in a lenth of fuel hose between tank and filter. Truck will start but won't stay running. Runs with starting fluid. Help me