98 Buick Lesabre Stalls

a lot of these gm vehicles have fuel pump problems. I am not sure if this would be one. Get the fuel pressure checked. If its down even a little you may need a new fuel pump and/or filter.

I had the exact same problem but on a much earlier Buick, an 89 Regal. It never set any codes. On this one it turned out to be a bad ECM. This problem was well known to Buick technical reps, since there had been a bad run of semiconductors used in that series. Unlikely that even GM would continue a bad run that long.

Problem is that there are a lot of manufacturing defects that don't show up for many years. And there is right now a serious problem with counterfeit semiconductors on the market... many of them almost meet specs, but might not.

Things like cold solder joints and poorly-anchored heat sinks may not be a problem now but can turn into big trouble after a few years of temperature cycling. Same goes with bad welds on the lead wires of transistors and ICs.

This is why the military requires extensive temperature cycling tests before accepting anything. The auto industry is not so demanding.

--scott

Clean the throttle plate. Gas filter changed lately.

could also be a sticking torque conv lockup solinoid or valve...

Mark

Yep. M, can your friend throw the trans into neutral when the car threatens to stall? If the car recovers it's probably a stuck torque converter clutch solenoid.

If the car still threatens to stall, check the EGR system (EGR valve, etc.)

Michael