NeoG

Hey all, new owner of a 2010 IS250 Sports Luxury I got about a month ago. If I leave the car overnight or longer, the ignition will quit just after it starts to fire with no error lights or OBD codes. It's like the engine never started at all. It will always start the second time guaranteed, with no sign of hesitation. I've read about 30 threads on starting, and I did find one interesting tidbit, that the 2IS will seem to quit starting the first time after the battery has been disconnected. Is it possible it's getting into a state like the battery has been disconnected if left for any decent amount of time? None of my settings or data appear to be erased, is there any way to know for sure if this is what's happening? (something I can check that only happens after a battery disconnect)

The battery terminal connections are solid, voltage overnight is about 12.6 before starting. I'm thinking it still could be a clapped battery? No idea how old it is since it came in the car, but looks in reasonable condition.

Appreciate any thoughts 🙏

Gville350

iTrader: (10)

I would check the negative ground wire leading FROM the battery terminal. I remember reading some members having issues with their cables leading from the negative terminal not have full grounding to the chassis or something. Corrosion perhaps? Been a while, I don't recall everything that had been stated.

2013FSport

iTrader: (2)

At the very least have it load tested to eliminate it as the source if the age is unknown. In hot climates the underhood temps take a batteries life in ~4years.

I am not aware of a single fuse that would not show other repercussions if it failed, so I'll roll the dice on the battery. If during cranking, it dips to 10volts or so, that may be enough to recreate a 50 first date scene and reset electronics.

NeoG

I got the battery load tested today, I think it was a fairly basic test but it came back 12.83v nominal, 579CCA under load which apparently is much more than the car needs to start. It's pointing towards the battery not being the reason I think.

2013FSport

iTrader: (2)

From my build thread, I found this. Guessing it goes here?

I think your post belongs here... Needs to started twice

2013FSport

iTrader: (2)

I'm going to say up front, this could be painful journey. Did it do this when you bought it? Has it always done the entire month you've owned it?

What if anything do you know about its history and what are you willing to put into correcting the condition? As in, time, money, maybe a higher end DMM that captures Min/Max voltage.

If it were mine, I would start by disconnecting the battery and pull every fuse related to Ignition, starting, fuel injection, and things of that nature looking for a bad connection.

Before restoring power I would also lift the cover on the engine ECU and unplug and inspect all 12 or 14 plugs full of connectors just to see if by chance it corrects it.

This one shot in 12 hours makes it hard to troubleshoot in a change ONE thing at a time approach to solve the mystery. I do suggest you document everything you do in notes so a month from now you can recount the full journey.

Are you willing to spend some money on test equipment?

NeoG

Just chiming in to say that after the battery was load tested it hasn't done the same thing since. It was tested during a dealer service so maybe they did something, but they didn't say anything. So I'll keep monitoring the situation but for now I can't replicate it.

NeoG

Providing closure to this post - yesterday the battery has given up the ghost. I guess the quirks were early signs of failure.

Protholl

Thanks for coming back and giving us the solution.