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Cadillac Repair/Engine Skipping When Going Up a Hill


QUESTION: Hello, you are the only expert I could find on this website that works on General Motors cars. I have a 1992 Buick Century 3.3 that has started skipping when going up a hill or putting a strain on the engine. Can you tell me what you think is causing this and where to start looking. I put a new crank sensor and fuel filter on last year. Could stale gasoline cause this? Any help will be greatly appreciated. Stephen

ANSWER: Hi Stephen,

The first thing we need to do is define what you mean by "skipping." Does the engine just have no power, but running smooth? No power and running rough? Engine speeding up, but car not going anywhere like a transmission slipping? When you refer to stale gas, what are you referring to? Yen which the car was not used? Why did you change the fuel filter a year ago? Power problems? Just for maintenance issues?
I am sure I can assist you, but the answers you give me will make a difference.

---------- FOLLOW-UP ----------

QUESTION: Thank you for your help. First, by skipping, I mean the car seems to just be running not on all 6 cylinders when I start up a hill. Maybe like one cylinder is not firing. On level ground it will run fine as long as I don't press the accelerator down much. I don't believe it is a transmission problem. I recently had the fluid and filter replaced. The reason I had the fuel filter and crank sensor changed at the same time is because after driving the car and turning it off, it had to sit about an hour before it would start. I had a new crank sensor, so I had the mechanic change them both at the same time. I have not had that issue since. He said that the fuel filter was very dirty. The filter was made in China and I have not had a lot of luck with Chinese made parts of anything. I have been driving my other car for a couple of months and letting this one sit is the reason I mention stale gas. I have tried blowing it out on the 4 lane road nearby by pushing the accelerator to the floor board and letting the engine go to 85mph. It will run smooth and then start skipping again on and off doing that. It hasn't been to long since I changed the plugs and wires. I use AC Delco plugs and wires. When I last changed the plugs, I put in what the book called for. It ran terrible. I had to go to the next hotter plug which fixed that. I was thinking it might be a fuel injector. Can a fuel injector be cleaned without having to replace it? I know gasoline with ethanol sucks but pure gasoline is not available where I live. I hope this information will help you tell me where to start to get this fixed. Again, any help will be appreciated. Stephen

Thanks for the great rating. I was thinking, you may not be able to recreate what is going on, but before you do all of this, have the fuel pressure checked as well. The reason is that since you are dropping the tank, if bad, you can change the fuel pump at the same time.

It really does not matter if the fuel filter was from China. Most are. What is more important is that your mechanic said it was very dirty. This is a concern, because although after time, fuel filters bguy oecome dirty, it has to remembered that if a lot of sediment was observed, changing the filter is only a temporary bandaid to conceal a real problem.
In the fuel tank at the inlet tube is what is known as a "sock." The sock is a very fine mesh screen that is supposed to prevent dirt, sediment and whatever other kind of garbage that is in the fuel tank from even reaching the filter. The sock could be dislodged. It sounds if a year ago the filter was very dirty, the mechanic should have recommended dropping the fuel tank, and having the tank cleaned of the debris, and changing the sock. They are only about $10.
Gas quality these days is garbage. Underground tanks crack, get dirt and water inside them and that goes into your tank.
I would recommend pulling the filter and see if dirty again, which I would bet it is. Drop the tank. Pull sending unit and empty tank as best as possible. If lots of rust in it, you are going to need to get a new fuel tank.
Install tank. Install a couple of gallons of gas. Install a bottle of fuel injector cleaner. Change the filter. If you can, have the fuel line from the tank to the throttle body or fuel injectors, and blow a air hose through it. Connect the filter and the engine side of the fuel line. Fill the tank and only use one bottle of heat, for any possible water in the system. Take the car out on your hills. From your description, this is the first plsace I would go and it just might take care of your problem.
Let me know.


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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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