I just bought a 1996 buick riviera series 2 supercharged. First few weeks ran great, no problems. Recently i've been having misfires especially when I press the gas pedal down more, and going up hill. It seems to run good when its first started up but it starts misfiring when warm. What could be going on? What's the little things i should be checking first? It seems to misfire after 3000 rpms but it will vary. I also have a leaky coolant. Does that have anything to do with it?

SOURCE: Random Cylinder Misfire

Im having the same problem with a 96 buick century. I wondering if its the coil packs. The plugs and wires have 8000miles of use. So i think it shouldnt be them. But same symptoms, engine code P0300.

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: Buick century misfire

it could be thermosat...i would also check EGR valve the are common to stick out and cause misfires

SOURCE: i have a 1996 buick century 3.1L. misfire # 1 cylinder

add some additive and take apart and clean again. change the fuel filter also cause it sounds like theres something clogging somewhere and it will take some trys to get it all out

Jeffry Williamson

• 5 Answers
• Posted on Feb 16, 2009

SOURCE: 95 buick riviera supercharger

you can not put a regular 3800 intake in place of the 3800 super charged engine,the compression ratio is lower than the regular 3800 engine.......!