Stumbling and hesitation

[kitttransam]

So I posted not too long ago about fuel pressure problems I thought I had. My truck keeps hesitating and stumbles about half throttle. It does come out of it once it picks up speed. So what I've done, replaced fuel pump, fuel filter, cleaned injectors the diy way. Found a bad vacuum connector on the fuel regulator fixed that. Had new o2's in it for a while now, put my old ones back in. Checked vacuum and it's at about 18. Stays stable at higher Rpms. No service engine light is coming on at all. And I did check for codes anyway and nothing. Spark plugs are fairly new in it. I do have my old ones and they don't look too bad. Thinking about swapping those out to see if there's a difference. This is on a 99 Silverado 2500 6.0 and any ideas or advice is really needed.

[Brianibew]

I had the same problem and replaced my fuel pressure regulator and fixed the problem. Once I removed the regulator and turned it upside down, drops of fuel came out of the vacuum side and I knew then it was no good. Fairly cheap part as well. Good luck.

[kitttransam]

Well I believe I finally found my problem. I decided to pull my plugs and found 3 that had small cracks on the ceramic where the boot goes on. Sad thing is they were just a few months old. But I reused my old wires. Don't know if that had anything to do with it. So bought a whole new set of plugs and wires and drove it and I didn't feel or hear the hesitation.

[kitttransam]

Been thinking overnight. What's the possibility of either a crank or cam sensor going bad? But to where it's not setting a code. Or timing chain is too loose? Truck has over 220k.