I have a 1998 Chevy 1500 p/u with the 5.0 litre engine. It became very hard to start, especially when cold(sitting for long periods of time). I took it to a mechanic and was told it was the timing chain. Spent $1200 letting them replace the timing chain and it still wont start after sitting overnight. Replaced the spider injection system myself and thought I had the issue solved, but it still ran rough once cranked. I broke the pcv valve hose while installing the injection system. Replace the assembly with a new one and now it runs great once you get it cranked. However, getting it cranked is next to impossible. Turns over and fires like it wants to start, but just won't quite start. The mechanic that replaced the timing chain says there is a "wetting" issue, whatever that means. Once the truck has been cranked it runs great! No misses, no hesitations and fires back up with just a bump of the key. I am at a loss for what could be wrong!
RepairPal Certified shops can diagnose and repair your 1998 Chevrolet C1500. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
https://youtu.be/u4yS9maoS_M Link above is to a how to video. Hint - no need to drain coolant as it shows in vid - just swap out the sensor.