I have a 91 K1500 RCSB with a 350 and a 5 speed. Last week it started stumbling and stalling. No codes. So I assumed the fuel pump was failing. I replaced it and the filter. It ran good until yesterday. About 700 miles on the new pump and filter. It started loosing power like it was starving for fuel. I got a CEL with codes 24 and 44. It can't rev above 2300prms. I shut it off at a gas station and tried again after a few minutes and it ran good for about 20 miles. It then ran good for another 20 miles or so. I repeated this until I got home. about 130 miles total. I went through the TBI about a year ago with new filters on the injectors. But did not replace them. Should I be thinking the fuel pump relay? Maybe injectors? I plan on testing the fuel pressure this weekend. But It ran good for the the twenty miles each time. Any help would be appreciated.