My Bonneville will start and run like a top for a short time then will bog down, chug and die. If I try to start it after it dies, I have to pump the gas to keep it going and it runs badly when I do with huge clouds of weird smelling exhaust. Sometimes if i continue to pump the gas i can get the exhaust to subside and the car to idle normally for a bit until it dies again a short time later and the process starts over. If i wait an hour or two it will start again and run well for another short time. I can hear the fuel pump engage when the key is turned on. I took it to a mechanic and he replaced the mass air flow sensor, but that did nothing except give me a large bill and leave me stranded on the side of the road minutes after leaving the shop.
My car has 152000 miles.
Hey there, thanks for writing in about your 2003 Pontiac Bonneville. You'll need to have the fuel pressure checked when it dies to see if the fuel pressure is too low causing the loss of power. You should also have the computer scanned to see if you are getting the camshaft and crankshaft sensor codes and the data that it is showing is correct. If you would like to have this scoped out for you, a certified technician from YourMechanic can come to your car's location to diagnose your vehicle's loss of power and have this repaired.
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