07 Buick rainier 4.2 ran great cut it off next day wont start. Full of gas with good gas pressure. New battery fluids full. Turn over slowly. Has timing chain. Good fuses Can time jump with chain?

Make sure battery has a full charge and battery connections are all good. Have a helper crank it while you check for spark at the plugs. If spark everywhere, check fuel pressure.
Is this vehicle computer controlled?

How long since a tune-up? Can you check for applicable trouble codes?
Generally if it cranks good but won't start, have a helper crank it while you check for spark at the spark plugs. If spark everywhere, use a gage and check proper fuel pressure and fuel injector pulse. Make sure the battery has a full charge. Check your security system, where applicable. Only crank the starter for a few seconds at a time, let it cool off, a little.

Change ignition barrel or get a new key cut try spraying lubricating oil down the barrel

is the security light on or flashing? it sounds as if the security system has been activated possibly due to bad transponder or pass lock sensor.

Check oil at dipstick for too much gas in oil thinning it to the point where the engine seized and won't turn over. If the cylinder was full of gas, this is a possibility. If the cylinder was full of gas, the fuel injector(s) might be stuck open causing this problem. Good luck on this problem.

sorry to say it needs a fuel pump/of-course the tank is now full

It's probably the mass airflow sensor and/or oxygen sensors.

With a new plug and fresh gas it should start. Check to make sure there isn't a kill switch turned off or that the gas petcock from the tank to the carb is on.

How did you check the fuel filter? Disconnecting it from the fuel line that goes to the carb is the best way, making sure the gas is turned on under the tank. Bleed off a little gas into a can or something just to make sure the filter isn't plugged.

The last thing I'd do is take off the air filter and spray a little starting fluid in the carb. It may start and run several times if there is old gas in there somewhere. Remember the bowl on the carb is probably still full of old gas. After some fresh fuel reaches the plug it should start and continue to run.

(You might drain the bowl on the carb of ols gas before you go any further)

Good luck!

Sirwriter

it's a default sensor to keep from blowing motor, you need to check your radiator for leaks. If that doesn't fix the problem , change your alternator. :)

Hi centi1999.First of all,from what you discribe,it will NOT be you fuel pump.Accually,the problem that you describe is very common.The security system has a problem.The pass-key sensor will most likelt be the problem.You have to replace the key cylinder lock because the sensor is not sold seperatly.Try this,try to start the car,after you turn the key all the way forward,let it go.the key will stay in the run possition as if the car had started.leave it there.It will take about 5 to 10 minutes for the security light stops flashing.Then turn the key back to the off position,remove the key,then try to start the car.This should reset the security system for a while.But,you will have to replace the pass-key sensor to fix the problem.Good luck.