Hey guys, I've been having this slight idle surge and knocking noise (it sounds like a slight knock mixed with an exhaust leak if that makes any sense) around 2000 rpms for a while now. I'm starting to think that one (or more) of my injectors is weak and making an odd noise. I haven't done a buzz test yet, but hopefully will be doing one in the next week or two. I'm getting no codes at all, which isn't helping me diagnose this problem. My other theory is that fuel pressure might be low, but I don't have a fuel pressure gauge yet.

At fully warmed up idle, ICP is 475-480 and IPR % is 8.5. I'm not sure if these numbers are normal or not as I searched and found about 20 different answers lol. I did unplug the ICP sensor while the truck was running, and got a SES light and the ICP jumped up to 725. I didn't drive it with the sensor unplugged though so not sure if it was better. I did notice that the slight idle surge was still there with the sensor unplugged though. I know there's another thread titled "major idle surge", but I didn't want to hijack his thread, especially since my idle surge isn't major and I have that slight knocking noise. As always, thanks for any advice and pointers

 

 

Check the CAC Tube Bands

 

I have not done the hutch and harpoon mod yet. Once I get to like 2300 rpms and up the noise goes away for the most part. As for the CAC boots, I had them off when I did glow plugs, and it's very possible I might've put them on too loose or too tight when I put them back on. I've also been debating on ordering the riffraff boots as the stock ones look pretty worn out.