You have two temp sensors one for the gauge and one for the computer if not working right computer don't know the right fuel to air mixture. I have 3 95 Chevy 2500 5.7L and had a lot of problems with temp sensor would not run good at all when first started until it was warm I put new temp sensor in run better cold then warm with no power, took a couple to get a good sensor. Good luck don't sound like there's too many more parts you could change