So my brother bought my dads 15.5 LML as my dad just got his 2024 ZR2 Duramax (thing is pretty rad inside and comes 1.5” tall than my truck). Warning, major lack of pics lol
We are doing some “fix it before it really breaks” on it. One of which was a cp3 conversion. We have not installed one of these at the shop yet and I liked the fact this is drop in with everything you need and no tuning.
My brother attempted tear down during the week before I go over there yesterday. He wound up killing an a/c hose and had enough lol. So I jumped in from that point and kept on tearing it down. Had the old cp4 out by lunch and pulled the regulator to see if it was coming apart. She was all clean in there (truck has 125k on it).
Couple things in the instruction that don’t really make sense. They want you to remove the adapter plate off the cp4 but they provide you with a new adapter plate to put in the cp3. once the cp3 is in, the instruction on where and when to install the fuel lines is way off. Best I can say is route ALL the fuel lines in loosely before tightening them down, I think I had lines on and off 3 times before finally getting them right. You get a new fuel supply line (one for the stock fuel filter and one if you deleted the fuel filter), new high pressure line from pump to rail and rail plug. They also show a pic of the fuel temp sensor adapter going in the a/c bracket bolt hole. Yeah that one is for the compressor but you have enough line to the next hole forward of that one that is slightly to the driver side. It clears the compressor just fine
You do need to massage the high pressure rail to rail cross over line to keep it off the new cp3 and remove the brace the instructions tell you do. They want you to remove the line completely as well as the low pressure feed lines but being the turbo was making that hard to do, it was easy enough to do all that while in the truck still. I also had to tweak the cp3 return line so the rubber line fit nicely.
Once it all settled in, reassembled the rest of the truck and had it running by 6 that night. Truck runs awesome and no hiccups from this kit. No weird part throttle, no rattles, feels just like it did with the cp4.
If this is your first time doing this, plan on 2-3 days to do it unless you got a lot of mechanical experience.
We are doing some “fix it before it really breaks” on it. One of which was a cp3 conversion. We have not installed one of these at the shop yet and I liked the fact this is drop in with everything you need and no tuning.
My brother attempted tear down during the week before I go over there yesterday. He wound up killing an a/c hose and had enough lol. So I jumped in from that point and kept on tearing it down. Had the old cp4 out by lunch and pulled the regulator to see if it was coming apart. She was all clean in there (truck has 125k on it).
Couple things in the instruction that don’t really make sense. They want you to remove the adapter plate off the cp4 but they provide you with a new adapter plate to put in the cp3. once the cp3 is in, the instruction on where and when to install the fuel lines is way off. Best I can say is route ALL the fuel lines in loosely before tightening them down, I think I had lines on and off 3 times before finally getting them right. You get a new fuel supply line (one for the stock fuel filter and one if you deleted the fuel filter), new high pressure line from pump to rail and rail plug. They also show a pic of the fuel temp sensor adapter going in the a/c bracket bolt hole. Yeah that one is for the compressor but you have enough line to the next hole forward of that one that is slightly to the driver side. It clears the compressor just fine
You do need to massage the high pressure rail to rail cross over line to keep it off the new cp3 and remove the brace the instructions tell you do. They want you to remove the line completely as well as the low pressure feed lines but being the turbo was making that hard to do, it was easy enough to do all that while in the truck still. I also had to tweak the cp3 return line so the rubber line fit nicely.
Once it all settled in, reassembled the rest of the truck and had it running by 6 that night. Truck runs awesome and no hiccups from this kit. No weird part throttle, no rattles, feels just like it did with the cp4.
If this is your first time doing this, plan on 2-3 days to do it unless you got a lot of mechanical experience.
