Long crank/hard start after sitting overnight

Question

I have a friend with an '08 Escalade which has a strange problem starting after sitting overnight, sometimes it'll crank fine for a couple seconds then all the sudden slow down before the engine finally catches. Sometimes it'll just take longer to start than usual. With both issues after running for a couple seconds and shutting it off it does not do it again until you let it sit for a while.

So far I have changed the main negative and positive battery cables but so far I don't think that's made a difference. Here are some videos of both issues.

Slow crank: https://youtu.be/KSsY2a7XqaU

Crank after running for 5 secs:https://youtu.be/hhDQKkqrtsE

Next video taken a some days later (day after replacing battery cables)

Long crank time: https://youtu.be/sxFxM3wwZ6o

I'm not totally sure what's going on, maybe a leaky injector(s) causing a partial hydrolock? It does have a slightly rough idle, but it's not misfiring. I checked the current draw of bank a (fuse 24 I think?) Injectors and coils and it all seems consistent. Not really sure what's going on here and I was hoping someone might have some input.

BTW there are no codes in the engine computer at all only other codes are for the brake pedal switch

Answer 1

The first video sounds like it could be injectors. It is how it would sound if the cylinders were flooded. One way to tell if this is a possibility would be to smell the oil and check its level. If it smells like there's a lot of fuel it in, the injectors are very high on the suspect list.

I'm not sure on the third video, but that's exactly how I'd expect an LS based engine to start when cold. That is NOT a long crank time. It fires within three seconds, which is completely normal. I've owned several different LS based vehicles and for the most part sounds exactly like that. There's no hesitation like is in the first video. Even the 2nd video isn't abnormal in starting. It is a bit longer, but really nothing to be concerned about. As long as it starts as it does in the 3rd video all the time, I'd suggest there is no issue.