FWizard

The car takes noticeably longer to turn over compared to normal. If I depress the start button twice and then try to start the car, it fires up instantly almost every time. When cranking, it turns quickly so I doubt its the battery.

When you press the start button twice, does the fuel pump become active? I'm wondering if my fuel pressure regulator is faulty? The FPR recall was done a few years ago iirc. How can I test the FPR?

mk416

Pretty sure the fuel pump starts priming as soon as the car is on (not ready mode).

lobuxracer

iTrader: (2)

The system isn't that simple. There are multiple fuel pumps doing different things in the system. I doubt it is any of them.

How old are your plugs, and how many kms are on the vehicle?

FWizard

Multiple fuel pumps sounds scary! There is just under 60,000 km on it, so about 37,000 miles. Whatever happens when you push the start button twice allows the car to start instantly almost every time. This is a bugger...

lobuxracer

iTrader: (2)

Could also be this: https://www.clublexus.com/forums/is-...back-asap.html. Pretty low mileage for a starter problem, but not all are perfect from the factory.

AFA the fuel system, there is a pump (one) in the fuel tank that pumps low pressure fuel to the engine bay. There are two feeds - one to the low pressure injectors, one to the two HPFPs, one on each valve cover. Unless you've got something weird going on, the fuel pump in the tank works just like the old school fuel systems with a return, except the return in this case is directly back to the tank. Low pressure return fuel never leaves the fuel cell (big bonus for evaporative emissions). Regulated low pressure output goes forward via two tubes.

The engine runs the vast majority of the time on the direct injectors, and starts on them exclusively. So you would need to have something very odd happening to prevent fuel from pressurizing the HPFPs, especially at your odometer. Plugs are due at 100k km according to Lexus (but not Denso). So, if I were guessing, I'd say you have some contamination in your fuel and would recommend a "drying" agent as it sounds a little like you might have water in it.

FWizard

Thanks lobux for the explanation. I was reading other Lexus threads about a fuel pump check valve. If working properly, it should leave the fuel pressurized in the lines after shutoff. Would you happen to know how to manually activate the fuel pump? As a test, I was thinking of running the pump first manually and then start the car.

lobuxracer

iTrader: (2)

Techstream is the only way I know to actuate the fuel pump manually.