Kubs

Just to close this out, it ended up being the charcoal canister. I got a P0446 code and replaced the vent valve and purge solenoid. The truck stopped stalling but code would come back every couple weeks. I replaced the charcoal canister and its been golden.

Like a continuity test? No I didnt. But I would expect it to be more random than a very specific event making it stall if they were faulty.

Ok, we might be on to something here... I did get a P0446 a few weeks ago but cleared it and it hasnt come back. I have a purge solenoid I ordered just sitting in the garage. I will swap that. But also I cant get it to stall right now, unless I load the car back in the trailer and go drive. Yeah I checked and both are fully seated and not loose. I had a similar thought as I did have the negative terminal off a lot recently during the engine work.

Small update. It stalled a couple more times, but only after towing a trailer for about an hour. And ONLY when backing up... Still no codes. Its been fine for almost 2 weeks since towing. Im very confused... It seems maybe its load induced, but then triggered by light throttle reversing. Any ideas?

Friday I was able to do the relearn procedure. No issues since then, so fingers crossed that was it!

I went ahead and replaced the crank sensor. It was less than $30 and in stock at Summit by my house. I need to borrow a scan tool from a friend local so I can do the relearn tonight, but it starts ok for now. It did that before also though, until it didnt, lol.

So if you have read my other thread I spent the last 10 months doing a number of "fixes" on my truck. Its a 2018 5.3L with a BTR L86 DoD delete cam, LS7 lifters, rebuilt heads. new timing gear, chain, tensioner, oil pump, cam sensor, VVT solenoid, L86 intake and L86 throttle body. I just got it back from the tuner on Friday where everything went well and the tuner actually commented on how well it runs. On Sunday I was out making a couple short trips to various stores (might be important information). Less than 5 min, run in the store, come out, start the truck and go to the next one. On the 3rd stop, the truck stalled backing into a parking spot. Went in the store came out and long cranked no start the first time. Then fired up and I drove to the end of the parking lot waiting to pull out. It stalled again and wouldnt start. After a couple attempts it fired up and drove back home fine. Zero codes this entire time. I had my cheap Foxwell scanner with me and was checking live data on the way. Timing looked good, fuel trims good, fuel pressure, etc. Yesterday it did it again only it wouldnt start for about 15 min or more. Would just crank sputter and immediately die. Again watching the data, nothing seemed to be out of whack. I tried the flood clear foot to the floor method and it would try to start more than with no throttle input but still die. I dont know if it was the repeated attempts or just luck, but I held the throttle about half way and it fired right up and drove home fine. I got back to my house, shut it off and it restarted no problem 5 times. This whole time there are no codes! The only sensor I didnt replace possibly related to starting and stalling is the crank position. Does this sound like something an intermittent CKP sensor would do? I would expect there to be a code with it though... Any thoughts?

Closing the loop on this, replacing the injector allowed the truck to run well and be tuned. It made 304hp and 333ftlbs on the rollers, with a 33" tall A/T tire and 93 octane. Unfortunately I dont have a comparison to before all the work but it feels pretty healthy. Very close to some 6.2L trucks I have driven.

Truck is currently at the tuner. The rough idle was a dead driver side O2, but we are now getting fuel trims about 15% different side to side. Pass side is taking a lot of fuel out and cyl 4 spark plug was BLACK. I think I have a hung up injector. Hopefully that clears it up and I can finally drive this again.

Reviving this. I had to step away for multiple reasons. I had the heads re-done with new valves as when the cam jumped time it bent all the intake valves. Its back together and starts and runs, but will idle rough. Along with the new cam I also changed to the L86 intake and TB. It might just need a tune now. I cant datalog though because I am relying on the AFM disabler in the OBD port to allow me to test fire until I can get it to the tuner.

So pushrods wasnt the issue. Rotated the engine to where cyl 1 had both intake and exhaust valves closed. Then I thought if I loosen a rocker I should see the spring move a little. Nothing. They are closed. I got it the rest of the way apart over the weekend. The cam bolt backed out and the gear spun on the cam a little making it out of time and lacking compression. It also destroyed the pin to the point I cant get it out so Im out $400 for a brand new cam also... A little background. I took the engine apart to replace the VVT after a P0016 code. I did a new cam gear/phaser, new bolt, tensioner, etc at that time. When I got it back together it developed a lifter tick right off the bat. I suspect it had been going out for a while and sitting with no pressure in it finally did it in. I then took it apart again to do the DoD delete with LS7 lifters, new trays, cam, valve springs and seals. I reused the cam gear and bolt that had 2min of run time. GM says if you re-use the cam bolt the new torque spec is 47ft/lbs + 50° instead of +90°. I dont think this is tight enough apparently. New cam, gear and bolt on order, and hopefully this is the last time I put this engine together.

I just got done doing the DoD delete on my '18 L83 Silverado. I replaced the cam with a BTR L86 cam (very mild) new lifters, lifter trays, dod delete plugs, all new VVT gears, chain, tensioner, oil pump etc. I also added a 6.2L intake manifold and TB during reassembly. The dots on the cam gear and crank lined up perfect, and engine spun by hand no problem on reassembly. Once back together I held the throttle down and cranked to build oil pressure before starting. Foot off the throttle it fired right up as soon as I hit the key. Idled beautiful without a miss, hesitation, lifter tick (reason for the tear down in the first place) or any odd noises. After a few minutes of idling while I was checking for leaks and listening, the truck just shut off. No bangs, rattles, smoke, nothing. Just stopped like someone turned the key off. Now when I crank the engine spins like it has no compression. Very free. No codes or check engine light either. Feeling defeated I called it night cause it was like 10pm and decided to tackle it again today. Im going to pull some plugs and check compression, and also pull a rocker cover to inspect, but what would cause it to lose compression all of a sudden? How could it start and run great, and then not have anything? Im at a total loss really. Anyone else experience this?

I have been using this for about a month. So far so good. https://www.amazon.com/gp/product/B074XKGNYY/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

The only changes are Bilstein 5100 shocks with the fronts on the highest setting, and then a 1/4" spacer on the bottom strut mount for an additional 0.5" lift. Im around 2.25" total level on the front, rear is all stock.

https://cart.bilsteinus.com/details?id=1764298763850174162&fyv=true&Year=8043155490883070947&Make=4463563413472551677&Model=1723229799825481433&Submodel=5482975663341996073&Pos=Front&En=4144253263211943131