98 gmc wont start

I have a 98 gmc 1500. while driving down the road the truck dies. The first thing that came to mind was the fuel pump, but the fuel pump is good. I then changed the fuel filter. Still does not start. I checked for spark and it is good. This happened ounce before I had it towed in. It was in the shop for four days and they could not find anything wrong. All they could tell me is at the time the truck died it was getting -40% fuel but the pump was good. I am getting spark, fuel but it will not start any help would be great. you can sent responses to [email protected]

Need to know what the fuel pressure is when it won't start. You need 55-60 PSI to start.

//2000CAYukon