Occasionally when starting my 99 Buick Lesabre, there is a very rough idle and feels like it may stall. The car also has some trouble accelerating occasionally. Spark plugs and fuel filter are new, battery is charged, air filter is clean and Check Engine Light does not come on. Recently tried Lucus Fuel Injector Cleaner with no change. Suggestions?

SOURCE: rough idle

fuel filters rarley cause idle problems. i would look at the egr valve or possible vaccume leaks.

SOURCE: 99 buick Lesabre

hey thanks for bringing me up to speed. ive been working on many other problems but with your great explanation i remember.
we need to check the compression on that cyl. and compare it to the compression on 2 other cylinders your choice.
but before you do this get a can of carb cleaner . and with the car idling spray around the intake manifold in the area of #6 cyl. what we are looking for is a small vacuum leak that would also act like this. with the engine idling and spraying around the intake the engines idle sould not change and if it does when you spray you have an intake leaking.
let me know how it turns out.
later
paul

SOURCE: Blows no heat 1995 Buick Custom LeSabre

change the thermostat

SOURCE: 1987 Buick Lesabre T stalling and running rough

I just had the same problem. Replaced the fuel filter,still crappy idle and no acceleration. I replaced the fump pump along with the wiring harness and the fuel pump screen and my cars purrs like a kitten,has back to normal acceleration and idles better than before. Hope this is some sort of help to you. I did it myself. Total cost, a little over $120. Good luck. By the way, your fuel pump should be pushing out about 65 lbs of pressure. is it ???

SOURCE: 99 buick lesabre started running rough know check

take it have theme read the codes maybe a vaccum leak,mass air flow sensor,egr valve could be numerous things the code will tell you