Sudden crank-no start.... but no codes

[okcguy]

2016 with 86k miles. Just installed a catch can this last weekend and everything was hooked up correctly. Normally get gas at Costco (87, ethanol) and was 1/4 tank before work but they're in the opposite direction so I stopped at a 7-11 to get me thru today and finish filling up tomorrow when I'm near Costco. Added about 1/4 tank of 100% gas at the 7-11.

Went to work and on my way back stopped at a gas station but wouldn't turn over leaving. At first I thought maybe I let off the brake a little too quick after the start button so I turned it off. Tried again and no go. Would crank for about half a sec then wait and crank again on its own but never fired up. This repeated several times until I turned it off. Thought something from the catch can had come loose but no. Even then I'm sure I'd get a normal start and just a CEL for a vac leak. Hooked up my Noco battery booster but it was cycling thru the lights so maybe I couldn't get a good ground. Finally called a tow and chalked it up to bad gas. While waiting for it, tried starting again and same crank scenario.

Got to the shop and a guy put on their bigger Noco pack although he didn't try starting beforehand. Started right up with his pack. He said we could try my Noco again to see if it's a bad battery but I told him I wanted to restart it myself untouched once his pack was off. Started again. Restarted just fine 5 more times. He put on his code reader and nothing stored.No rough idle, sputtering, etc. Battery was replaced in Oct. I'm stumped and so is the shop. Has anyone experienced this or willing to take a guess at possibilities? It has been extremely hot (100F +) the last few days.

 

[okcguy]

Finally able to duplicate it. First button push, several crank attempts. Second push, one failed crank. Third time, no issues.

 

[FalconHeavy]

2016 with 86k miles. Just installed a catch can this last weekend and everything was hooked up correctly. Normally get gas at Costco (87, ethanol) and was 1/4 tank before work but they're in the opposite direction so I stopped at a 7-11 to get me thru today and finish filling up tomorrow when I'm near Costco. Added about 1/4 tank of 100% gas at the 7-11.

Went to work and on my way back stopped at a gas station but wouldn't turn over leaving. At first I thought maybe I let off the brake a little too quick after the start button so I turned it off. Tried again and no go. Would crank for about half a sec then wait and crank again on its own but never fired up. This repeated several times until I turned it off. Thought something from the catch can had come loose but no. Even then I'm sure I'd get a normal start and just a CEL for a vac leak. Hooked up my Noco battery booster but it was cycling thru the lights so maybe I couldn't get a good ground. Finally called a tow and chalked it up to bad gas. While waiting for it, tried starting again and same crank scenario.

Got to the shop and a guy put on their bigger Noco pack although he didn't try starting beforehand. Started right up with his pack. He said we could try my Noco again to see if it's a bad battery but I told him I wanted to restart it myself untouched once his pack was off. Started again. Restarted just fine 5 more times. He put on his code reader and nothing stored.No rough idle, sputtering, etc. Battery was replaced in Oct. I'm stumped and so is the shop. Has anyone experienced this or willing to take a guess at possibilities? It has been extremely hot (100F +) the last few days.

My G80 has the same issue. After 3 months of not driving it and about 10 Techs, and 2 tows, I think I narrowed it down to Heat Soak in the Cam sensor.. I purchased the sensors and when I get the time, I'll be switching them out.

My issue was sporadic draw back on power, and then stalling out, over a few days.
I have access to Mechanics at work so most of the time taken to track issues was free, but over weeks.

All work was done without the car leaving parking lot. Did not drive between issues, we just jumped and let idle, and ran around building for testing.

-Had a stutter so I did the plugs.
-Ran rough so checked all coil packs.
-Battery is 2 months old. (good)
-Checked power from trunk and fuse. (normal)
-Checked all fuel pumps. (everything within parameter)
-Checked Cats / Had one clogged. (Cleared the front 2)

In the end, we did not find the issue... but, We all started to realize that it was stalling out after the engine was hot. We'd start it, let it idle for a minute.. (everything ran normal) Pulled it out and did a brake stand in it.. (ran fine) Drove around the building 3 times.. (forth time it stalled) Would not restart unless car was cooled down.. Even with jump pack.

One of the garages mentioned heat soak causing the issue maybe, and mentioned Hyundai's he's worked on in years past, so thats where I'm at now.