05RollaXRS

Did you have your 2 high pressure fuel pumps checked (fronts) and the one rear low pressure fuel pump? They were replaced under recall for all of us (the fronts). The rear one was only for the early 2015 build date ones, if you heard a whine noise coming from the rear and the ECU was reflashed. Could be a weak fuel pump causing the issue.

Yri

This is actually very much a possibility, yet there has yet to be a post in which the low pressure fuel pump, meaning the 'main' fuel pump which pumps fuel from the tank, has malfunctioned or is not providing enough fuel. It would be a good idea to do as Rolla suggested, however, replacing the HPFP's outside of warranty (if you don't have one) would be incredibly costly. Besides, the HPFP could rarely go wrong since Lexus did the recall back in '18, after they fixed the pulsation dampers and the cover (I think thats what it was?), and the HPFP doesn't actually really rely on electricity for its power source (rather, it uses electricity for a sort of 'peak-and-release' solenoid), instead it relies on the camshaft to pump fuel.

CAHWY128

Issues like these are very frustrating. I had an 1985 Mustang SVO which was a 4 cylinder Turbo. I wish I had kept it. It would cut out at about 4K RPM full throttle. The dealer could not fix it and neither could a couple of independent shops. I was extremely frustrated. They all tested my fuel pump and said it was fine. I had a friend who was a shade tree mechanic and he took one drive in it and told me it was my fuel pump. So I went bought a new one on his recommendation and he installed it. It was the fuel pump. The pump could pass the pressure test that the dealer did but under load its volume would fall off and pressure would lower and the engine would die out.

Another thought is the fuel is draining back into the tank and the pump has to re-pump all the gas into the line. The reason mechanics struggle with issues like this as the computer does not spit out a code telling them where to look. Then you either have to find an expert on the car or play the replace parts and pray it is the problem game.

djl

Long cranking time is a very common symptom of the fuel system not holding pressure when the engine is off, could be the fuel pump or the pressure regulator. The fuel in the lines/rails runs back into the tank and it takes time for the pump to rebuild proper pressure before the engine will start. A simple fuel pressure test will easily verify this.

Assuming the engine runs perfectly normal once started, your injectors are fine.

Ab175

Thanks for all the responses, I will call a second dealership today, and try to get them to take a look at it. Hopefully I can get this sorted soon.

Ab175

The recalls have all been done, it definitely could be a weak fuel pump.

LoSt180

Following to see if there's ever a resolution to this. Mine has only "long cranked" once or twice, but it was enough to make me raise an eyebrow. First time was after grabbing lunch, so it wasn't sitting for a while either.

Ab175

Mysteriously, I have not experienced the long cranking either yesterday or today. It's as if the car fixed itself. Very weird but I will keep an eye on it. For now I'm grateful as it has saved me a 40 minute drive to the dealership. I want to say that the injector cleaner helped but I have a hard time believing that it would act so fast considering I haven't even drained the whole tank yet. I am very confused yet satisfied, I hope this issue does not come back, but if it does I will keep y'all posted.

05RollaXRS

Did you clean your battery terminals? Maybe, that might have had some affect on it. I also think the fuel injector cleaner would act so quickly and make a very noticeable difference in such a short amount of time.

Yri

One thing that would make sense is if one of the terminals, namely the positive terminal, was so corroded that the alternator wasn't charging the battery right, leading to longer starts.

Ab175

Every single mechanic/tech I have spoken to has told me that corrosion would not cause a long crank time but rather a complete failure to start, so despite the fact that I did clean it, I do not believe this is what led to the solution. Also, the starter was cranking very strongly in each case of the long start so I do not believe that it was related to the battery/charging system/starter at all. I guess the injector cleaner worked some magic. Not bad for an 8$ bottle.

The positive terminal had no corrosion on it weirdly and I did not clean it at all. Also, the battery tested at 100% charge with the engine off multiple times.
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Yri

Odd. I doubt a fuel additive could do that much on a single start, but who knows. There are trillions upon trillions of variables anyway. Please keep this thread updated if it ever happens again, though. Interesting topic, nonetheless.

EDIT: Also, one thing I remember about these cars is that they hate being below a quarter tank of fuel, and that the fuel pump is not primed until the ECU receives an RPM signal. If your car had low fuel then that might also partially be the case.

Ab175

It was a little over a quarter tank of fuel that I burned with the additive for what it is worth. I agree that it is very weird. This issue has occurred for a while now across varying levels of fuel ranging from nearly empty to full. No difference. It is a very peculiar issue but for now, it is gone. I will update this thread if I see the issue again.

ariescrown

You are very fortunate that your problem is now seemingly corrected. I had the same problem after going through a flash flood. The water and or dirt it may have picked up from the problem killed my starter and it had to be replaced. My problem started out just like yours. I was not so lucky I had to get an new Lexus starter and gaskets etc. I had a $1,000 Ded. on my comprehensive and that is what it cost me. Also Lexus went through the car with a fine tooth comb to see if any other damage happened because of the water. They insisted it was only the starter that had a problem. I can only imagine how much more money they got from the insurance company. Google says that the most common cause of starter loss is "water and dirt".