1990 Century 3.3 Stalls

Good Morning.
been reading the threads for days in hopes of finding a solution, I have a 1990 Century 3.3 that stalls after running 10 minutes or so. Idles great and when you give it a little gas it stalls, after a few tries it wont start anymore. when cold it starts fine, and runs a few minutes then starts stalling again.

We replaced the control module, crank sensor, put another maf airflow sensor we took of a junkyard car, the new sensor is $250 and not even sure if thats the problem. took it to the buick dealer. no codes came up. they said it have good fuel pressure. we replaced pretty much all the hose connections in the air lines. does anyone have any suggestions for me? its my daughters car. she really cant afford another right now, and already threw in $200 and it still doesnt run.
Thanks everyone

Welcome to AF!!

I'll take a stab at this one. Check the ignition module under the coils. Sometimes when they go bad they will work fine when the engine is cold but when the car warms up then it will shut down. Obviously the dealership is full of a bunch of Techs who can only diagnose when the computer tells them what is wrong. I would also check all connections from the battery and as many grounds as you can find.

Finally, did you check the fuel pressure while the car was running? Sometimes the fuel pressure regulator will fail when the car is warm. The next time the car stalls and won't start try spraying some starter fluid into the throttle body while someone cranks the car if it starts then the problem is on the fuel side. If not check for spark. At least that will give you an idea where to look. Good Luck!

GTP DAD.. Thank you. the module under the coils was the first thing i replaced. the one thing the dealer did was check the fuel pressure through the entire process, and it was fine.
possible the throttle sensor? i was reading on another thread here that a fouled fuel injector was the problem. all the mechanics I talk to say the car would still run... I am this close.... to setting it on fire.... I am having dreams at night about the buick... arghhhh.....

If you replace the ignition module make sure it is properly grounded. Sometimes the area under the module gets corroded or rusty and that will prevent it from working properly. Try the starting fluid thing to see if the car will start. At least that way you will be able to determine if this is an ignition or fuel problem. The other issue is that the ECM may have gone bad and is not sending the correct signals to the injectors to fire them in the correct order.

... I am this close.... to setting it on fire.... I am having dreams at night about the buick... arghhhh.....Me too. Ive head that if the engine is ever over heated it can cause the thermostat or the sensor that tells the ecm when the engine is cold or hot and sets up the fuel management, its something like the temp control module or something similar. A friend had the same problem and thats what was wrong with it. Ive had injector problems that make mine do similar things, but it does that all the time.

GTP DAD.. Thank you. the module under the coils was the first thing i replaced. the one thing the dealer did was check the fuel pressure through the entire process, and it was fine.
possible the throttle sensor? i was reading on another thread here that a fouled fuel injector was the problem. all the mechanics I talk to say the car would still run... I am this close.... to setting it on fire.... I am having dreams at night about the buick... arghhhh.....

No matter how many parts you replace, you still have to do the basic tests. Did you ever check, before or after you replaced the parts, for spark at the plugs. When the no start occurs, have a helper crank the engine, while you check for spark at the plugs. If you have spark, great, then we can move to another system. From reading your posts, you never did say, that you had spark. Maybe I missed it.

no I didn't check the spark when cranking after it wont start. can you explain how i do this? I am an autoglass tecnician not a mechanic.

thank you all for your attempts to help me...

Probably the best way is to get a cheap spark-tester from the auto store. You pull a plug boot off a spark plug, put the boot on the spark tester. The spark-tester should have a ground clip, you clip that to metal part of the engine/ good ground. Have helper crank the engine while you watch for a spark to jump the gap on the spark tester.

You can also use a known good spark-plug in place of the store bought tester, just break off the ground electrode, put the plug boot on the spark plug, lay metal part of plug on metal part of engine, the point being, you have to ground the plug. Then have a helper crank the vehicle while you watch for spark.

I have used a phillips screwdriver on some occasions, put the end of the screwdriver in the plug boot, hold the shank of the screwdriver close to an engine ground/ metal part. Have helper crank it, watch for spark to jump from screwdriver to ground. The last time I tired that, I don't remember seeing the spark, but I darn sure felt it. It's better not to hold anything in your hand, although I still do it once in a while. I've been bit several times by secondary ignition voltage, hasn't killed me yet, but I never learned to like it.

Andy F- I have a 1990 Buick Century that cuts out when driving. Sometimes
it happend when braking, and sometimes just driving with foot on the
gas pedal. It does not do it all the time, but when it starts it is pretty
consistent. I'v had my mechanic check the car. He said he checked the wires
and some where loose. He fixed that. The problem keeps reoccurring,
and our mechanic has checked it out three times. The car runs ok
for a few days or a week, and then it starts stalling out again. Help please!!

Crank position sensor is going bad! Also check the fuel pump to make sure your fuel pressure is good when this happens but this is a classic sign of a CPS going bad.