No code stored. I tried to erase with scanner but MIL stays on.
Maybe the scanner does not read all the codes, like ABS?
All I can suggest at this point is to look and look again for an electrical connector that is dangling loose.
Something was messed up when the repairs were done. The plugs should not be wet, What kind of light did you use to test for spark?
[quote=āGaytanmichelle, post:1, topic:97816, full:trueā]
After some research, i pulled the throttle body and cleaned it with carb cleaner and wire brush. [/quote]Two bad ideas. Only throttle body cleaner and a soft brush (e.g. an old toothbrush) should be used for this job.
Iāve had that happen, fixing something seeming unrelated to the engine working, then the car cranks but doesnāt start. Not unusual for it to be caused by a flooded condition in the cylinders. And the cloud of black smoke you saw seems consistent with this. When diagnosing and testing itās quite easy to inadvertently flood the cylinders with gasoline and not realize it. Suggest you focus on that as the most likely cause.
So what to do about it? Removing and cleaning the spark plugs usually wonāt do the trick b/c the cylinders remain flooded with gasoline. Youāll have to remove the plugs, disable the fuel pump and ignition system, and crank the engine a bit to expel most of that gas in the cylinders out the spark plug holes. Careful, any sparks might set the engine ablaze. Keep a fire extinguisher on hand at all times. Then let the engine sit with the spark plugs removed for a day or two to let any remaining gasoline evaporate from the cylinders. That will usually allow a flooded engine to start.
If it still wonāt start, first off check to make sure you now have gas and spark and the camshaft is turning during cranking. If so, then you may have damaged the cat by forcing raw gasoline through it prior. A shop could temporarily disconnect the cat to see if it would start then. Best of luck.
Sorry for my lame cure, but it worked, an hour and a half with battery maintainer of every 10 or 15 minutes cranking no longer than 10 seconds worked, all the mechanics I talked to had no answer, no similar experience, but free sure was my favorite solution, vs a tow and who knows what parts thrown at it. Sorry I cannot help you pinpoint it, as in my case starter fluid had no effect. Of course it was a 15 degree day and I ded not feel like playing under the hood. Could have been a frozen gas line as I think I dumped some heet in for kicks, but like I say it was 3 years ago and no problem since. Are you in sub 32 degree condition? Have a heated garage you can drag it into for half a day or so? I guess I would have to think a fuel freeze up based on reading my own post.
@Barkydog @Mustangman @GeorgeSanJose
Okay. About to give it another go. Its pretty cold weather in Illinois so i have to work when the sun is out. Hopefully, today is my lucky day.
Keep everyone posted.
Me and my family would hate to still be stranded on NYE.
Another shot in the darkā¦ Maybe the crank position sensor or cam position has failed? Yes, I know that should throw a P0335 code or a P0340 code but if the ECU canāt identify it as such, you might still get fuel and spark may still be seen.
You might consider doing your homework before replying with a smart alek answer as the TRAILBLAZER NEVER came with a V6.
Try this - pull your fuel pump relay (or fuse) and try to start it. It may start and run for a few seconds then stall just with the fuel thatās in the intake manifold. If so then plug the fuel pump relay back in and try to restart the engine. If it starts then stalls due to re-flooding then check your fuel rail pressure with a gauge. It may read high. If so you may have a bad pressure regulator.
When you try this depress the accelerator part way while cranking to help sweep out the excessive gas.
Did you disconnect the battery prior to or during the rack R&R?
Iāve seen this before where the computer can compensate for issues and over time have the adjustments be way off to one side but it still runs normally to the driver. Then disconnect the battery for an extended period and those settings are lost, it reverts back to the defaults and the engine wonāt run.
Never use a wire brush on either spark plugs or the TB. The ceramic insulator of the plug is harder than the metal bristles and it will leave metal in the pores of the insulator. The TB may be coated with a thin paint like coating to make it smoother for airflow and an abrasive brush will ruin that finish.
How did you verify spark?
The Coil Over Plug (COP) setup on the TB makes it very tough to do by probing so curious how you verified spark. It seems to be missing spark so this is an area of concern. You could disconnect the COP assembly, remove the plug and then reinsert it into the COP. Make sure threaded body of plug is on grounded metal of engine and have someone crank while watching for sparkā¦
The most concerning is the presence of a MIL and no codes. The ECM could be damaged. I assume all of the monitors are reset and flashing on the reader? Does your reader support this level of diagnostic? Just trying to see if the ECM is reporting other things correctly.
Have you tried starting spray? Itās far more volatile than gas and will ignite under conditions that the gas will not. It may help provide some additional information if the engine sputters or tries to start with the spray. Inject directly into TB while someone cranks versus spray and then try starting. Do not over spray, if it fails to sputter, stop after a few seconds.
Good luck!
I wonder if this unique engine might gain some life as a turbocharged or supercharged engine in larger applications, like the Silverado and Tahoe, replacing the current V8s.
[quote=āMustangman, post:27, topic:97816, full:trueā] Maybe the crank position sensor or cam position has failed?
[/quote]
I pulled the Cam sensor and it looked ok. Just dirty. No cracks. The connector and wires look good too.
I do wonder if thereās spark, fuel and air, then maybe the spark timing is off. But I think thereās a DTC for that.
I actally spent the evening last night drying out the cylinders.
Battery on a trickle charger,
Removed all the spark plugs and the FP relay,
Used a blowgun w a long rubber hose on the end to reach into where to plugs sit and dry up the cylinders (air compresor 30psi).
In the drivers seat w the gas pedal WOT,
Cranked over 5-6 times.
Repeated blowguning all the cylinders and dry cranking for about a hr. W a flashlight Ć could see the piston head was dry, not shiny anymore.
Reinstalled all the plugs and coil packs. Left one pack off. (I have a sparkplug test light, metal probe looks like tip of a plug on one end and has plugwire boot on the other). Set up the testlight and crank. Testlight fires repeatedly. Ok. Install coilpack.
Reinstall intake baffle, so MAF is also in play.
FP relay still off to not allow new fuel, crank several times WOT to allow air in and spark plugs can ignite whatever fuel still may be left. No sputter so figured we are good and dry.
Reinstall FP relay.
Cranked again normally, no start.
Check fuel sprayed out of the valve on the fuel rail. Ok.
Cranked several times more, no start, barely a shadow of a sputter but didnt catch. At this point is was night and freezing, so stopped right there.
Not IMO
This is a very old engine design by now . . . dates back to 2002, AFAIK
GM is probably not going to replace their current V8 engines with an old design
They already stopped building the 4 and 5 banger derivatives, at least for the US market, so theyāve already made up their minds
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Spark testers for COP designs have been around for a long time
Various kinds, in fact
IMO it sounds like OP did a reasonably good job of verifying spark 
Did you check the fuel pressure regulator? There is a hose, if you pull it off and there is gas it is bad.
They did supercharge the 3.8L V6,and GM shows little inclination to eliminate pushrods engines.
My opinion hasnāt changed
āGM shows little inclination to eliminate pushrods engines.ā
Thank you for making my point for me 
Since GM fullsize trucks largely pushrod engines, AFAIK, thereās no reason to replace their current generation of engines with this archaic DOHC inline six design
GM no longer even sells any of the vehicles which used the inline 4, 5 and 6 of that engine family. Not here, anyways
Still no start.
Tried everything that you guys suggestedā¦ I am cracking my head trying to figure this out.
Thinking about calling a mobile mechanic but dont want to waste money if he cant figure out whats wrong with it.