2002 Buick Century won't start unless it wants to!

My wife owns a 2002 Buick Century and within the past year it has started acting very strangely. The engine will turn and turn and turn but never catch. At first, I assumed it may be the fuel pump. Where it was stranded was too noisy, so I had it towed home and had my wife turn the key so I could listen for a hum from the fuel pump. The fuel pump hummed, so that wasn’t it. I had her try to start it again, and what do you know? Started right up! Car acted fine for about a week, then it stranded my wife again. She waited about 30 minutes, tried again and it started. So randomly it will not want to start, but if you try again every 15 minutes or so, you may get lucky and it will start. We then assumed maybe the anti-theft system was acting up, but sometimes it would start within 5 minutes of not starting, so there went that idea. I have changed the spark plugs, wires, and fuel filter just in case. The last straw we’ve had with it was after 4 days of not being able to get it to start at all. We would try and try and try, nothing. So I gave in and had it towed to a mechanic shop. Wouldn’t you know, it starts right up for them. Every time! Like a champ. They are keeping it and trying it every day. Driving it around assuming maybe the tow trip jarred something back into place, so hopefully driving it will eventually cause it to not start for them so they can run diagnostics on it. The problem is, it is going on two weeks now since they’ve had it and it isn’t giving them any trouble at all! Typical. It has been a major inconvenience not having her car, but I don’t just want to be out $150 to get the car back and have it strand my wife somewhere again, only to tow it back to the shop and it work just fine for them. I am at my wits end with this car. I do not have a clue what it could be, any suggestions? (Other than having a priest perform an exorcism on it?)

I’d try to determine whether its a ignition or a fuel problem. Next time it happens, spray some starter fluid in the air intake and see if it wants to start. It may not stay running but will buy you a clue.
If it seems like it doesnt want to start ar all, it likely isn’t fuel related but may be ignition related.

Well, I’m not a mechanic so take it for what its worth. Those symptoms sure sound like a failing GM fuel pump. I’ve had tons of Buick fuel pump problems. Once had the thing not start in a ramp 50 miles away. Had it towed home and started right up again. Stall, then start up, stall, etc. I used to carry a 5 lb sledge hammer to bang on the tank just in case. Now I also had an injector that would stay open once in a while and would cause extended cranking until the pressure could be built up again. It was a bugger to find but finally in the shop after repeated starts, all of a suddent the fuel pressure dropped off. I hope they have a fuel pressure tester and test light on it all the time while they are trying to get it to fail.

If its not fuel related, next I would suspect the crank sensor, then coil or ignition module. Its the kind of thing that causes you to trade the car to avoid the aggravation.


Have the guys hooked up a fuel pressure gauge?
Just because the engine starts DOESN’T mean you don’t have a fuel pressure problem.

Here’s two cars I worked on recently that had fuel pressure problems, but started every time.
I’m not going to bother mentioning what they were, because that’s not the point.

  1. The car had a long crank before starting.
    The car ran well enough.
    The MIL was on (P0171, due to the lean condition)
    The fuel pressure at the rail was 15psi too low
    Fuel pressure at the rain would instantly drop to 0 when you shut off the engine
    It had a returnless fuel system.
    The fuel pressure regulator (this particular car a combined fuel filter/regulator assembly) was returning too much fuel to the tank, rather than sending enough fuel to the rail.

  2. The car had a long crank before starting
    The car ran well enough
    No MIL
    Fuel pressure at the rail would drop off instantly when you shut off the engine.
    Fuel pressures were within specs at idle, but the pressure at the rail would instantly drop to 0 after shutting off the engine
    The fuel pump check valve was faulty. That is why the rail pressure wouldn’t hold with the engine off.

Are these guys testing and diagnosing, or only hoping that something will fail permanently?

Have these guys hooked up their scanner, pulled DTCs, looked at live data PIDs, looked for TSBs, etc.

Are these guys pretty familiar with GM cars?

The car never stalls, once it’s running it will continue to do so. It is just the starting that is the issue. Could it still be the fuel pump when it doesn’t start even though you can hear it hum as if it’s working?

The shop is called Promatic, here in Glenpool, OK. I do not really know their qualifications, but they are the only shop in town. They said they are waiting for the car to "“not start” for them so they can test the fuel pressure. They haven’t really done anything yet except for start the car and drive it around a bit, stop it and start it again, multiple times throughout the day in hopes it will not start for them so they can then diagnose it. They said since there is no pattern with it as far as when it won’t start, (as in mornings mainly, or cold starts, or after driving for awhile), that it could be a large number of things. Since it is so random, they believe the best bet is to wait until it acts up for them too.

Remcow, if we decide to just eat the $150 and get the car back, I will definitely try your suggestion when it won’t start again. Narrowing it down to fuel or spark is definitely a big necessary step.

Thank you all for your time and suggestions. I really appreciate it.

Could it be a hot soak issue in the ignition pack/coil? When you stop the car the temp under the hood goes up this may cause an issue for the coil under certain cases. Normally these will start well cold but the restarts in a short time are a problem. When the coil is hot it gives a weak spark if this is the issue. Wet weather and condensation can also affect a poor coil pack. Also a flakey/ failing crank angle sensor can cause this as a more random issue. Good news it is easy to try.

I know this thread is old but hopefully that means that you found an answer? Anyway my '02 century is doing the exact same thing and has been for about 8 months. Please let me know if you found an answer.

Will I just found this Discussion and I also have a 2002 Buick Century doing exactly what was described in the original post. Have had it into the shop for this many times. Here is the symptoms I have discovered: I thought it was heat related as it was worse in the summer I thought, But what I just discovered is, by the way it had just set for 2 hours and it is 28 degrees outside when it just did it, when you are starting the car if on your first attempt to start it you keep at it until it starts it will start every time, but if you attempt to start it, let go of it and attempt to try again it will not start, the starter is turning it over but sounds like no spark, just grinds and will not start. Turn it off with nothing on, not even the radio and somewhere between 20 min. and an hour, try it and it will start, but make sure it goes on the first attempt or the cycle starts again. I am convinced it is a sensor or the computer, but have not figured it out yet. So if you want to duplicate the problem attempt to start, let up and attempt again. Maybe then the shop can scan it and find the cause. Good luck and please reply here if you find it.

It was the computer

So, in the end it’s a total mystery. My son has a 2002 Buick Century with the same modus operandi. It runs great for two-three weeks then, out of nowhere, won’t start. You turn the ignition and it cranks and cranks but it doesn’t “turn over” and start. BUT … if you wait 30 minutes or so, it’ll start right up. The last time it did it I had a mechanic rush to the parking lot where it was at but… guess what? It started up just fine. He has checked it in the normal state and everything is OK. His theory is that it has something to do with the anti-theft device. I notice when it did it to me I tried to start, turned the key back, then tried again. The car runs great, ALWAYS starts after that 30 minute wait but this is getting old. I really don’t think the car needs a fuel pump. This has been happening for nearly two years! Help.

My son has a 2002 Buick Century with exactly the same problem. Out of nowhere, it will crank but won’t turn over. Leave it alone for 30-40 minutes and it starts just fine. One mechanic theorized it was an anti-theft device problem: The car thinks someone is trying to start it and shuts down to prevent that. If anyone knows, please let me know. Thanks! bigsmith55@gmail.com

Same here, hillbilly_flyer. If you find an answer I’m at bigsmith55@gmail.com Thanks mucho.

Since 2012?

Hillbiily has not been here for years. Also putting your email on an open web site is never a good idea.

Well old or not, I had bought a spare computer at the junk yard for $35. It’d take about 10 minutes to swap it and the chip to rule the computer out. I always had it in the trunk. Funny but the computer was never a problem. I left it in the trunk when I junked it.

Listen up guys if u want your buick century to start everytime heres your answer and its a notorious problem from 2000 to 2002 or 03 models… Change your camshaft posistion sensor take passenger tire off get a pulley puller to take pulley off and its two bolts and other end plugs right in bout 65 bucks all in all unless u want to pay a shop about 350 to 400 bucks… Have had this issue on few centurys save the extra and listen to me… For the Future ill go ahead and say your welcome

Your suspicion of the anti theft system was well warranted. GM vehicles of this vintage have had known issues with the system doing this on purpose due to the ignition switch not reading the key reliably every time. Not sure if you have this same system or not… I forget the exact years but 02’ is close if not within the range. Most shops will interpret the anti theft as a bad crank sensor when it comes into play. I recall this is what I would often think as well when the vehicle presents with those symptoms…and often it is that damn security system. So one needs to pay attention. Look in to what system if any you have.

In addition to the anti theft system causing this…there is another area common that causes things like this and that again is the ignition switch…sometimes it does not apply power to all the wires it is supposed to energize…but just to mess with you…it will supply power to all the wires with the key in the run or on position…and then it loses contact in the start position. So as you are cranking the engine, you essentially shut the ignition off (which should not be possible)…its enough to drive you nuts.

You need to pay close attention during the failure…when you can get it to fail that is… watch the dash for the security light… read up on how to read the security light.

Also…if you have a different key… Take note of how many keys you do have…and mark them…so you know which ones function…and maybe which do not.

I would be paying very close attention to the anti theft system, the ignition keys…and the ignition switch itself. I have had the misfortune of diagnosing and repairing many of these vehicles…and it is usually the key…or the ignition not being able to read the key for whatever reasons. There is a way to troubleshoot the anti theft system and also disable the pass lock or pass key system…whatever the name of it is…I forget. Its in my crusty dusty note books that follow me around.