1990 Buick Century

ah, a mechanic.

This car is 22 - 23 years old. they can plug it in and give you a diagnosis

Have you replaced the rubber pad on the brake pedal? Never mind...

You said "When I come to a stop my car will cut off on me and it sounds real rough." Does it die on you, or run real rough? Can't do both.

Have you checked the fuel quality? Engine oil and ATF levels? Air conditioner turned off all the time?

I don't know if there's a way to test the ignition control module, but that's probably it. This is what it looks like.

Next time it acts up, get a can of that air for cleaning computers........it comes out cold. Shut off the car, spray the module until it's cool. If the car starts right up, you found your problem.

BTW- Since this happens when the car is hot, you can use the same method on all electrical/computerized components.

I have replace my igintion control module already

BTW- Since this happens when the car is hot, you can use the same method on all electrical/computerized components.

Cans of air are cheaper than replacing one component at a time. This allows you to forgo the 45 minute wait time, as well as cooling off specific components individually.

Sounds like a classic case of vapor lock to me.

http://en.wikipedia.org/wiki/Vapor_lock

You mentioned the "fuel filter, fuel pressure regulator", but not the fuel pump. Check the pump.

Could be the crankshaft position sensor....

http://www.fixya.com/cars/t1939468-locate_crank_sensor_1990_buick_century

It needs new tires.

Lyn, I think you've misdiagnosed the problem. He is using Bridgestone RE 92 tires, so they are fine. I have a feeling it's the muffler bearings.

Maybe, but this model had both a recall and a service bulletin to have the defective, leaky muffler bearings replaced. Maybe this particular vehicle was never repaired.

You're right. The 1984 to 1996 Buick Century, Pontiac 6000, Olds Ciera and Chevy Celebrity all had the recall, but it was only for VIN's beginning with a 1, 2 or 3. I read the recall and the cars that came with 14" wheels were prone to the leaky muffler bearings, but the ones with 15" wheels weren't affected.

Many customers with the 15" wheels complained, but GM said that it was due to a lack of maintenance. Customers were using the wrong lubricant, or they never serviced the bearing.

Have you considered that the exhaust system may be plugged up due to a collapsed catalytic converter?

Plugged or highly restricted exhaust will cause a similar rough idle and stalling problem and at 23 years old that's entirely possible.

Pull out one of your O2 sensors ans see if you get a get a lot of exhaust venting out of it and a noticeable gain in idle quality and starting. If so your converter is plugged.

I had a near identical issue with a 1989 Olds Ciera. On mine the torque converter was locking up after it got hot. Let it cool down and it was good for another 20 miles. Try shoving in neutral when it seems like it want to stall to see if it helps or there is a electrical connector on the top driver-side of the trans-axle that you can disconnect and it runs normal except you loose some torqueness. I gave mine to my brother and he drove it for two more years with the connector off and not return of the symptoms

I had a problem nearly exactly like that too. Drove me absolutely nuts. 1982 Vintage.

My symptoms were. Car warmed up. Let cool for about 20-30 minutes. Restart. Extremely rough idle.

I basically discovered that I had a huge vacuum leak. This car had a solenoid that was mounted on the valve cover and it happened to get to hot and it would stick.

The solenoid was connected to 12 V. When the engine was turned off, full vacuum was applied to the EGR valve. This was the anti-diesiling system.

Troubleshooting basically was plugging vacuum lines systematically when the problem occurred. This was probably one of the worst problems I had to hunt down.

That solenoid valve was sticking. Tell-tale was very poor vacuum.

I had the same problem with a 1989 Buick Century, same engine. After much frustration, and a few new fuel filters and pumps, the problem was solved with reconditioned fuel injectors. Seems the insulation on the coils deteriorates, and when hot, resistance drops to where the control module will not fire the injectors. Cheapest replacements I found (other than a wrecking yard) was at Knechts auto parts.

Why do you ask us? There is a parts salesman somewhere that had a very good Christmas while you guessed. Have you had anyone clear, and then see what trouble codes the engine,s computer has picked up? Have you had a compression test? Have you looked at those plug wires?

With your symptoms, and the car's age, you need to do some diagnosing/ Start with the trouble codes, and then we should be able to steer you in a better path than the one you are on.

I will gladly walk you through some simple low, or no cost checks if you need to.

You have been dragged all over the map so far. Battery, starter and alternator. Other than cables, not much left to sell you here is there?

Fuel filter and regulator. A fuel pump is much more common to fail than a regulator, but without checking, I would only be guessing.

Spark plugs are surely a starting point, but looking at the old plugs should have told someone a lot about the running of the engine.

As for the other parts, the valve could have been the culprit for the poor idling condition, but the sensors sounds like just guessing.

Let us know how you want to go.