I have just swapped motors in a 91 S-10 with a 2,5 L with a motor from an 88 w/ a 2.5 L. Every thing is hooked up and I have one problem. When the key is turned on the injector pumps a huge amount of fuel into the throttle body. The motor will try to start after you have cranked it for 15-20 seconds then wham the injector dumps a giant squirt of fuel and it dies. I cannot figure out what is causing this. I changed the fuel pump due to a prior problem with no fuel at the throttle body. I have changed the throttle body pressure regulator, the throttle position sensor and the injector. Please help, I am lost

 

when you changed motors did you change computers as well? im not sure if it would make a big dif or not but it may be somthing to look at.