Engine Performance problem
1997 Pontiac Grand Am 6 cyl Front Wheel Drive Automatic 133000 miles
My 1997 Pontiac Grand Am GT will start fine, but the power will flucuate when the gas or the brake is applied. Sometimes the car will die at very low speeds, like in parking lots. I have changed the coils, fuel filter, air filter and have checked the fuses. There is some oil leakage, but not excessive to the point where oil drips on the ground. At night time the lights flicker from dim to brighter and back to dim constantly. The dashboard lights do the same at night time. When I am at a stop, the car acts like it's going to die and sometimes does. I am hoping for some help and any ideas as money is very limited and I need my car to work. I am a single parent with financial limitations. Any ideas?
Have the charging system checked out to rule out the alternator could be the contributing factor for the other problems lacking the correct voltage to function properly such as sensor and actuators
June, 3, 2010 AT 11:23 AM
I had my alternator checked at autozone and it checks out to be good, I forgot to mention my battery was bad and was replaced, but did not fix my problem. What would be the next step I should take? Thank you for your help.
June, 3, 2010 AT 4:31 PM
What's the alternator output voltages while being load tested? Be advised the computer controls the alternator field generation circuit
June, 3, 2010 AT 5:29 PM
I am not too sure what the output voltage is while being load tested, I had one of the clerks at autozone test it for me and they said it tests fine. I will go back and have them check it again and I will let you know the output voltage. KIf it is not the alternator, then you are suggesting its a computer problem? I had some one recently told me it may be the motor mounts that could cause this problem as he had a similar problem, is that posible as well? The autozone rep, says I should start replacing sensors, but I do not want to replace them one by one till it's fixed and am not sure if that is accurate advice. I have notice the stalling and dieing problems happens in park when I depress the gas or brake. The car runs pretty smooth on the freeway, but as soon as I slow down to I believe first gear and almost stopping, between 0 to 1000 rpms is when I have the shuttering problem. After driving and I put the car in park, it will die everytime, but will easily turn back over. I hope this helps narrowing down my dilemma. Would oil pressure cause this fluxuation too, from a intake manifold gasket? I hope this is not too many questions. I appreciate your time.
June, 3, 2010 AT 5:33 PM
Clean out the idle air control valve, EGR and PCV valves and then test the throttle position sensor and manifold absolute pressure sensors. To include a fuel pressure check
June, 3, 2010 AT 5:45 PM
Ok, I will give it a shot and clean them out and let you know what I find. Thank you.
June, 3, 2010 AT 9:38 PM
Ok, I cleaned out the idle air control valve, the EGR and PCV valves and I still have the problem. How do you test the throttle position sensor and the MAP sensor? The EGR does not have a gasket and am unsure if that is an issue. Soon after I cleaned those 3 compnents I turned the Engine on and let it idle. It idles fine, with radio on, A/C on and I turned the wheels right then left and no problems. As soon as I press the break, the RPMS start to go down and the engine wants to shut of. Just what I notice thus far, Any other ideas why I figure out how to test the MAP and throttle Position sensor?
June, 3, 2010 AT 11:18 PM
I had my alternator tested and it has 12 volts come out and tests good. I replaced the PVC and the adjoining hose due to crack in the hose. I still am have the same power problems, especially when I depress the brake. Any other ideas, I would apreciate it very much.
June, 4, 2010 AT 6:52 PM
I believe I may have found the problem. It seems there is a vacuum leak in the the Power Brake Booster. I am waiting for the part and after I install it, I will let you guys know what happens. Thank you.
June, 5, 2010 AT 2:40 PM
I installed the brake power booster and new gaskets for the EGR. My car runs like a champ again, thanks to the new brake power booster and through some help of some mechanics. Thank you guys.