CELEBRATING 20 YEARS!

Today I started the car and when trying to put it in reverse, the car stalled but fired back up when I restarted. Just like before, no MIL light or fuel pump priming but will do just as you're turning the key to the start position...weird. Shutting down when shifting into Reverse has happened on a few other occasions, that's why I thought it might have something to do with the Ignition switch or there being slop in the steering column.

I'm stumped!

I've experienced a couple more engine cut out issues. Once while driving and once just placing the transmission in reverse. As mentioned before, there is slop in the steering column so I've decided to remove the column and send it in to be rebuilt. It may not solve my issues but it is possible it will...it needs to be done regardless.

Well it didn't resolve my problem but everything dealing with the steering column works great! One difference I have seen is that now it will not shut off when shifting into reverse.
So last week I used my scan tool when the car shut off and would not start back up. There was no communication between the scan tool and the PCM. I then wiggled the wires at the starter and just like that, the fuel pump pressurized, check engine light came on and the scan tool linked with the PCM. The problem is in the PCM power supply wires!
Chipping away a little at a time...

Baby steps, baby steps... Troubleshooting is always fun. Good luck on getting it nailed down and fixed.
I forgot another issue I had, where the screw terminal on the aftermarket fuse block was loose. It killed the fuel pump power and I think another circuit, might have been a feed to the ECM too. Might take a look there as well, depending on how your system is wired and routed. Don't forget wires that might be bumped by the steering shaft, or by the engine torquing differently when in reverse than in drive. Basically, anything that moves when you go to reverse. Even though that isn't causing it to stall, it used to and you still have the same problem with a different cause.

Thanks for helping Shawn. I want to get a GoPro camera to see and hear what goes on in that suspect area when it shuts down.
I decided to do some maintenance while I have the car up on wooden blocks, a little over a foot in the air. I fixed a small tranny oil leak, replaced the parking light housings, topped off the differential oil, cleaned the whole underside with 4 cans of brake cleaner (because of the oil leak), tightened one of the front sway bar end links and am currently in the process of replacing the transmission cooler lines with braided hose and AN fittings to the cooler.
Next on the list is replacing the way too long LS1 Trans Am accelerator cable with one from an '02 Silverado with a 6.0.

Go-Pro's are awesome. You might look into a magnetic base for it. We use them for work, and built a handful of bases with some strong neodymium magnets and a 1/4"-20 screw stud for the mount to screw onto (with a locknut). We put a couple layers of tape on the magnet to make it easier to remove and easier to clean. On flat steel, it was almost impossible to budge. We launched them on barges dropping into the water, some of them getting hit full force with jets of water, others getting jolted 10g's and barely moving at all, but no drilling or gluing required to mount them. Tie a string on it just in case if you want an added layer of protection against losing it.

I was about ready to buy a knock-off GoPro before we bought a handful of them for work that I can use when needed... Anyway, sounds like a plan. Good luck.

https://smile.amazon.com/Mutuactor-Powerful-Neodymium-Threaded-Pull-Force/dp/B07JKWCVTX/ref=sr_1_5?dchild=1&keywords=magnet+stud+1%2F4-20&qid=1611065852&sr=8-5

I think I my have found a solution to the intermittent power supply problem. I'm going to run a wire from the battery directly to the PSI fuse box, bypassing the starter. I ordered a Fuse box/ECM cable for a '97 Silverado, as it bolts directly to the battery. It was supposed to have arrived yesterday but I wasn't in as of today.

I then decided to replace the throttle cable because the one I installed with the swap was too long and tended to bind slightly, causing a jolt on initial acceleration. It can be a bit scary when driving in tight spaces. The cable I used was from a 2002 Trans Am without Traction Control. I also bought a cable bracket for an LS1 Fbody to mount on the intake manifold since I converted from DBW to DBC.
I read several times where other guys that had LS swapped their Montes (or some other G body) used the Throttle cable from a 5.3 or 6.0 Silverado. It seems as though the cable has come up a bit short. Maybe the routing is wrong...maybe I need another cable bracket.

Any thoughts or suggestions?

Throttle Cable Bracket 1 by Jose Mireles, on Flickr

I think I'd be looking at cable routing first. Is there a way to get that extra ~1 1/2"? Or is there a way to reroute the old (long) cable to loop a little more and not bind? Maybe just lube it with some white lithium or dry moly? I haven't ever tried to take one of these apart, might be easier said than done, but even if you can't get the cable out of the sleeve, sometimes you can make a slurry of rubbing alcohol and lube and it will get into tight places, then the alcohol evaporates and you have a lubed component.

I haven't measured the distance between the cable bracket and the TB, but I would think GM would keep that consistent between models such that an LS1 bracket with a truck cable shouldn't be a problem so I wouldn't get too far on the bracket path. I used a rigged up cable extension on mine (trying to keep factory kickdown function on the TH350 as well as give a mounting point for cruise), otherwise I'd tell you what worked for me

Shawn,

I lubed the cable with a little transmission oil. But that was 5 years ago. I ruined the cable by trying to remove it.
The Fbody cable bracket is different from the truck bracket too...I can make it work but not if it doesn't reach. I tried a couple of routing configurations, so perhaps I need to keep trying to find the correct way. I didn't get a whole lot of time to work on Saturday as we were preparing for last week's deep freeze.

How did you fair this week?

Not too bad in the scheme of it. Lost power for 24 hours, its an old house so it cooled off quick but with gas burners and a fireplace we kept it in the upper 40's. Froze my water heater (tankless outside), still waiting on replacement parts due last week. And sprung a leak in my RV fresh water tank, as well as in the pump. Looks like everything is going to come in this weekend to fix it all before I have to go out of town again Monday.
A few others in our area had no power for 2-3 days, water either cut off or on boil notice, and a few friends had bad water damage from busted pipes. One family was volunteering at a warming center when power came on at their place and thawed a busted pipe, flooded entire downstairs for hours before they got home. Thankfully we had nothing like that.

How did you guys do?

We were spared the brunt of the cold weather. We got plenty of snow on Sunday and some on Monday. We had plenty of pine to burn. The lows did drop into the mid teens and high temps in the 30's but none of that pipe splitting cold weather that east and central Texas got. Although that did remind me of the polar vortex blast we got 10 years ago...our lows hovered around 0* with highs in the teens. I had two busted pipes. Luckily I was home to shut off the main line.

I figured out solutions to both of my dilemmas.
1) The power supply to the PCM:
I removed the two PSI wires that bolted to the starter, ran them up top over the intake manifold and extended the wires directly to the battery. I noticed that the last six inches of wiring felt flimsy somehow...even had a different color of insulation, so those last 6 inches is what I cut off. Luckily, my battery has both side and top posts. The only thing needed to be finished is adding wire loom to make it look neatly and protect the wiring.

2) The accelerator cable:
I ended up using a cable from a '98-'04 Chevy Blazer with the 4.3 V6.th only modification was trimming the plastic clip that secures to the accelerator bracket...that was it! Its almost as if though it was made for my swap!

Very nice! Maybe those wires just got a little burnt under there? Either way, I hope that takes care of it permanently.

Thanks Shawn. It has been three weeks since I modified the power supply to the PCM and even so much as a hiccup. I'm cautiously optimistic that this dilemma is solved permanently.

I need to return to a former project that was put on hold due to the electrical problem...
1) see why the new pivot arm won't rotate in the HVAC case and get all that mess put back together so I can control the temperature in the car. I also want to get the A/C going...its already climbing into the low 80's here.
2) extend the differential vent line so it doesn't puke and coat everything back there in rear gear lube.