00 lesabre will not start

Hello and happy new years. I need help with my parents 2000 buick lesabre. 2 days ago car didnt want to start. This happen before like 2 months ago. Solution: sparks plugs were flooded with fuel thus bleed out the remaining gas forming on spark plugs thus replaced with better ones. Crank sensor was cleaned also. Then it started ok for 2 months. Now again to days has passed and cant start the car. I have replaced I think crank sensor ( sensor located bottom of water pump )this time and I think its something with sensors becuase spark plug is not sparking when cranking engine. Also, i did bleed out the remaining gas when took out spark plug and replace again new spark plugs. Also i notice battery needs booster. Car has 55k. Any tips will be appreciated. thank you.

ps Also: I came across yesterday with this recall online.

2000 Buick Lesabre Limited NHTSA Recall ID Number: 04V090000
Recall Date: FEB 24, 2004
Component: FUEL SYSTEM, GASOLINE:DELIVERY
Potential Units Affected: 910873
Summary: ON CERTAIN PASSENGER VEHICLES EQUIPPED WITH 3800 V6 (L36) ENGINES AND CERTAIN DELPHI FUEL PRESSURE REGULATORS, THE REGULATORS HAVE A MUCH HIGHER THAN USUAL RATE OF FUEL LEAKS. A LEAK CAN ALLOW FUEL TO ENTER THE INTAKE MANIFOLD THROUGH A VACUUM LINE. IF THE ENGINE DOES NOT START WHEN CRANKED, THE FUEL FROM THE LEAKING REGULATOR AND A MISTIMED SPARK CAN CAUSE A BACKFIRE.
Consequence: THE BACKFIRE CAN RUPTURE THE INTAKE MANIFOLD. THE RUPTURE OF THE INTAKE MANIFOLD CAN DISPLACE A FUEL LINE, PULLING AN INJECTOR OUT OF PLACE, AND CAUSING A FUEL LEAK AND POSSIBLE FIRE.
Remedy: DEALERS WILL INSTALL NEW FUEL PRESSURE REGULATORS WITH IMPROVED DIAPHRAGMS. THE RECALL WILL BE CONDUCTED IN PHASED MAILINGS. PHASE 1 WILL BEGIN ON JUNE 30, 2004, FOR THE 1998-2000 BUICK PARK AVENUE, LESABRE, 1998-2000 PONTIAC BONNEVILLE, 1998-1999 OLDSMOBILE EIGHTY-EIGHT, AND 2000 CHEVROLET MONTE CARLO AND IMPALA VEHICLES EQUPPED WITH 3.8L ENGINES. OWNERS SHOULD CONTACT BUICK AT 1-866-608-8080, OLDSMOBILE AT 1-800-630-6537, OR PONTIAC AT 1-800-620-7668.
Notes: GENERAL MOTORS CORP., 03054B

Take a plug wire off and insert a screwdriver into the wire end and place it near a ground (metal part on engine) and turn the engine over to see if you have spark from the screwdriver to ground. (You can buy an inline tester for this also). If it doesn’t have spark, you have either a bad crank sensor or it is installed incorrectly, or a bad ignition module under the coil packs. Let us know what you find. By the way, I did not mention the fuel system checks, until you let us know about spark. It sounds like you have plenty of fuel, by your description of the fuel on the plugs.

Hello. thank you for your reply.

Update:
At the previouse post; It was not the crankshaft sensor but the camshaft postion sensor that got replaced.
Anyways, Today this morning the car started just fine. Its running ok. Now, I still have doubts with what happened and afraid it may happen again. For now, Im taking it to the dealer to get it tested. I know something may be going soon because the sign of the problem happened twice. I know this much, when it happens the engine cranks slowly and too much of trying to start causes the battery to die. Even if I didnt know what part is causing the problem, this time I know I changed the spark plugs to the best quality and for sure changed the camshaft postion sensor.
Thank you again for your input.

From JP