Repeat failure: After fuel pump was replaced on 12-29-04, on 1-14-05 under same conditions - cold weather - expressway speed - the car lost power and stalled - would not restart and required tow to dealership. Analysis showed the replacement fuel pump also became defective. (car lost power and stalled on 12-28-04 and 12-29-04 and was towed to dealership, were the module was replaced.)

- Brighton, MI, USA

Repeat issue on 12-28-04 - cold weather, expressway speeds - no warning car lost power and stalled on expressway. Finally restarted after tow truck arrived. Stalled again on 12-29-04 same conditions - would not restart - towed to GM dealership. Fuel pump and system replaced.

- Brighton, MI, USA

I own a 2000 Pontiac Sunfire - purchased new. I had no problems until 2003 when my car would deccelerate for no reason while driving at any speed, hesitate while driving at any speed, or, after stopping at an intersection, simply would not allow acceleration. This has happened while trying to go through busy intersections. Very scary. One day in 2003 the car would not start, so I had it towed to a mechanic to research this problem. He replaced my fuel pump but the car was out of warranty, so I paid for this repair along with the tow. It did not take long for the problem to occur again. What is going on? I take good care of this vehicle and, if the fuel pump was the problem, this should not be happening again so soon. Second issue - early in 2004 I noticed the low coolant light coming on and off with no consistency. I checked the coolant reservoir and it was low. I added the proper coolant mixture but it didn't take long for the light to come on and off again - with no consistency. Shortly thereafter the check engine light was coming on and off. I again took it to my mechanic who reset something relating to the check engine light. But the very next day the light was on again. Now, it is always on. Please explain what is going on. I owe one more year on this vehicle and can't afford to have any major problems. The biggest issue is the hesitation and stalling of the car at anytime. There is no warning - it just happens. This is a disaster waiting to occur. My children ride in and drive this car. I don't need this worry on top of everything else. One more thing, about 1 year ago the air conditioner started malfunctioning. Not sure if it is related to the other complaints. It only works if you have the fan on the 3rd or 4th mark. If you put it on the 1st or 2nd mark, it will work (but not to capacity) only while the vehicle is moving. If you stop, it stops.

- Herscher, IL, USA

Problems with 2000 Pontiac Sunfire engine. The vehicle would crank sometimes but not start. On one occasion the vehicle attempted to crank and stalled in the process. The problem continued. The consumer was told that the starter had gone out, maybe there was an electrical problem, or the fuel pump. The fuel pump and sender ring was replaced. There was a burnt coolant smell and the valve cover gasket ruptured leaking oil.

- Jacksonville, FL, USA

2000 Pontiac Sunfire experiencing fuel pump malfunctions at vehicle age of 3.5 yrs. Car has been taken to muliple mechanics, all of whom suggest pump malfunction and reccommend replacement of fuel pump, filter and relay valve. Manufacturer warranty of 3 years or 36,000 miles has expired for this vehicle. Car initially taken into Pontiac dealership for servicing a problem with ignition. Engine would turn but not fire resulting in no ignition. Car owner paid for replacement of fuel pump, filter and relay valve.

- Victoria, TX, USA

Car has had numerous problems since day one. Brakes chatter, overheating, service engine light, cd player and speakers did not work. Now it stalls with no warning at all. Stalls at 70 mph going down highway. Has stalled while driving 3 or 4 times in the past two days. Checked out at service station on computer, and shows no problems. Have read many complaints here about the exact same problem. Bad fuel pump or something is causing car to stall. Then it takes from 10 to 15 minutes to start again. Some days it just won't start at all. Have had car checked many times, and no one can seem to find the problem. Anyone that can help here"?" I think GMC owes many, many consumers an explanation and repair of this very serious and potentially dangerous problem!

- Thompson, PA, USA