Probably need to check your gauge. GM pretty much uses around 58psi on everything.Originally Posted by TxJonathan
Probably need to check your gauge. GM pretty much uses around 58psi on everything.
Either way it shows the same pressure as my factory sierra so I know the fuel pressure isn't an issue
Can you post a data log please with cam counts, crank counts, ect, rpm, o2 voltages and trims. Almost sounds like an O2 is shorted at this point if it runs till going into closed loop and dies. Maybe even some photos around the engine of the grounds and where those grounds are attached on the body or frame. Then check to see if any codes are set after it dies too. Video at the same time of fuel pressure gauge would also help. Tune too, since you said it now had a tune in it.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
I'll go by today and get that info
Log module voltage and injector pulse widths too.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
2007 suburban.hpl
suburban 1 no vats.hpt
im not familiar with this program and still learning to navigate it. i believe i got most of the readings you asked for. This was with key on engine off, cranked during the data log.
Charge the battery up and grab another log. Right now voltage is way too low to fire.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
I've had several gen 4's act like a VATS issue with a bad cam sensor. Normally it will start at least every other try.. I had one stuck in the shop for a month where it would fire and immediately die. The little jumper harness on the cam sensor was pinned wrong. never set a cam code.
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This right here. Actually looks like the battery is bad.
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suburban01042024.hpl
Heres the new log with the suburban being charged with jumper cables. Did not start and only cranked during attempts. Also tried pressing down accelerator to see if would make difference.
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20240104_205810.jpg
Here's photos of the grounds on passenger head and driver head/firewall. I did not remove driver ground from block during delete only from firewall
Dumb question and maybe I missed it, but have you tried spraying brake cleaner down the intake to see what it does?
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I think he did, but not all brake clean is flammable anymore. Lawsuits and whatnot. Same reason WD40 doesn't burn anymore.
OK, so back to the basics. Was running before. Did cam swap. Now won't even fire with a factory replacement non DOD cam? Replaced front cover - I assume cam gear was installed with reluctor notches facing outward? It's showing cam counts so I assume so. I also assume the correct harness and cover was installed because of this, BUT it's also possible for it to be wired backwards and still show counts, so did you check wire to wire, connector to connector orientation for the new harness and sensor? Honestly I normally just cut the VVT wiring off and tape them up then re-use the harness and sensor that came off the motor for this reason. Might be worth trying that next if you're sure you don't have a stuck open injector and good fuel pressure while cranking and it holding that pressure.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
It's the original cover but I did replace the cam sensor but that was very recent. I was already having issues getting it running and only replaced it because I broke it a couple days ago. The truck didn't start for weeks before I replaced the sensor so I don't believe it's possible for the pins to be swapped since it's the same sensor from when it was running.
Have you done a compression check since installing the cam? Harness pins won't be the problem. Had to go back to the beginning to see where it doesn't have vvt.
You need 3 basic things to fire. Fuel that ignites with oxygen. Spark to ignite. Compression to combust.
The only other thing I can think of is the pushrods are either too long and holding the valves open after oil pressure builds and then has to bleed back off before it'll fire again, which actually goes hand and hand with the original install firing right up and running till pressure built and it died or I keep coming back to an injector issue. Either sticking shut, not flowing or stuck open dumping all of the fuel out of the rail. Compression check will show the pushrod issue. Popping the injectors up out of the intake manifold with the injectors attached and turning the key on will show one stuck open. Unplugging the coil connectors and then having someone else crank it over will show if the injectors are spraying. Usually you can smell the fuel to see if it's right and just didn't get a bunch of water pumped up or something that may have been poured into the tank while you weren't around? You can also take a small sample and see if it'll burn. Just keep your distance and go away away from the vehicle.
For it to randomly fire, run a few seconds then die I'm wondering on the pushrods, but I would think it would spin over quicker or you would hear the difference.
Have you checked fuses? It's definitely sparking and shows injector pulse and injectors are actually spraying? IF that's the case and the fuel will burn then that only leaves compression. Inj pulsewidth does look extremely high and is possibly flooding the motor, but...
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
I'll try a compression test next, it's hard to imagine that an injector would get stuck overnight. As far as pushrod length goes the kit didn't specify I needed different length rods and they appeared to be the same length when placed side by side with the non-dod rods.
I would always check push rod lengths with a cam/lifter change, but they are probably not the issue.
If you laid them side by side and were the same length then most likely not the problem.
I've only ever seen this one time, but the engine was so worn and the rings were seized in their lands that pulling the heads and retorqing them caused a big enough loss of compression that the engine wouldn't run anymore. Compression check should show that but you shouldn't have seen any cross hatch in the bores if that's the case.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
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