I'm working on a 09 Lexus is250 It will not run. It's had the fuel pump, Starter and battery replaced. that's all good it's not getting fuel to the cylinder's....Why.

Lexus IS250 repair manuals are available at the click of a mouse! Chilton's Lexus IS250 online manuals provide information for your car's diagnostics, do-it-yourself repairs, and general maintenance.
Chilton's Lexus IS250 repair manuals include diagrams, photos, and instructions you need to assist you in do-it-yourself IS250 repairs. ChiltonDIY online IS250 repair manuals cover automotive service and repairs, from diagnostic trouble codes and probable causes, electronic engine controls, and maintenance schedules, to brake and suspension issues, wiring diagrams and engine repairs, tune-up procedures, specifications, clutch and gearbox diagrams, and more.

Steven, Check for loose/slipping belt (tensioner) may not be working as it should, look for loose connections on battery and alternator.
If you had a digital volt meter, it could help diagnose problem much easier, lets say your car fails to crank, with headlights on, you can put the meter on the battery terminals and battery voltage is around 11.7V and bounce back to 12.2V or higher when lights are off, that would some what tell you the starter is defective and battery OK.
With car running the voltage should show approx, 14.0 V. or more which tells you the alternator is working OK.
If battery is checked when car is not running and falls below 12 volts the battery is weak and bound to fail. Ideally a good battery is 12.4 to 12.6 V. See links below for more helpful info. and test methods.
Charging System test multimeter
How To Check Charging System EricTheCarGuy
How to Test Car Battery with Multimeter

Check battery connections and voltage. fuel pump only runs for a few seconds to start and runs again while cranking.

check solonoid for starter , battery wires , cable from switch to solenoid on starter ,

The first thing you want to check for is the brake signal,without this signal it will not crank,this is the easy one make sure you get brake light,the second is to have the starter tested by a direct method,this gives the indication of the health of the starter

I have on 07 is250 and the power windows and trunk release were not working. There is a trunk/valet button in the glove box that needed depressed in order to make them work again.

Batteries currently last 3 years, have your battery tested and replaced

I would change the starter.Remove it and have it checked where you are going to purchase the starter.

My 2007 Lexus IS250 is dead, hooked up a charger. Charger keeps shutting off. Triple checked the cables, + - correct, still shuts off charger?

I had a similar experience just the other day, i stopped to get gas and turned the car off and when attempting to turn the car back on nothing would happen. Well, let me rephrase the lights inside and out would work as well as the ac and the radio. My initial train of thought was maybe it was the battery so i went and purchased a new battery which was around $100, I installed the new battery and the car still wouldn't start. Does your car make a clicking noise when you turn the inginition key or is it just silent? If it is silent, you might want to check to see if your starter has burned out. Luckly a friend of a friend does his own mechanical work and was able to remove and replace the starter for me. After the starter was replaced the car started right up and ran perfectly. Not sure where u live but in my area a starter ranges in price from $100-200, but they also charge a core fee ranging from $45+, which can be reimbursed if you bring in your old starter to the store. I would suggest getting a starter with a lifetime warranty as well, but thats just a suggestion.

Hope this helps,

brelic