Guest danray Posted July 8, 2007 Posted July 8, 2007 I am new to the forum and have searched for this problem, but have not found an occurance mentioned. My 2003 Lemans since new, has had this problem. After about 10 miles of riding, it coughs, spits back thru the air cleaner and generally does not want to run. The problem is more pronounced below 3000 RPM and above 3000 ft. and in hot weather. At less than 2000 ft. it is not present. It was checked over by dealer who made only slight adjustments, but did check sensors, etc. I rode it before picking it up and it ran ok at 800 ft. elev. and cool temperature. When I rode it first time back home at 4500 ft., it still had the problem. There is not a tank vacumn. I put a new ECU on with no change. I put a PC III with stock mapping on then. MC is stock. With fuel buttons set at max plus in all three ranges, I was able to get it to stop the poor running except in above 80 degree temperatures. It now has about 9000 miles on it. Does anyone have experience with these symptoms, or have a recommendation on what I should check next?
richard100t Posted July 9, 2007 Posted July 9, 2007 I am new to the forum and have searched for this problem, but have not found an occurance mentioned. My 2003 Lemans since new, has had this problem. After about 10 miles of riding, it coughs, spits back thru the air cleaner and generally does not want to run. The problem is more pronounced below 3000 RPM and above 3000 ft. and in hot weather. At less than 2000 ft. it is not present. It was checked over by dealer who made only slight adjustments, but did check sensors, etc. I rode it before picking it up and it ran ok at 800 ft. elev. and cool temperature. When I rode it first time back home at 4500 ft., it still had the problem. There is not a tank vacumn. I put a new ECU on with no change. I put a PC III with stock mapping on then. MC is stock. With fuel buttons set at max plus in all three ranges, I was able to get it to stop the poor running except in above 80 degree temperatures. It now has about 9000 miles on it. Does anyone have experience with these symptoms, or have a recommendation on what I should check next? It sounds like the throttle position sensor may need a minor adjustment. Your elevation shouldnt matter with fuel injection but I cant see whats going on there. Anyway mine would run great when its cool, then once heated up it would pop & cough at lower rpms & not run well. A dealer will sometimes hook the computer to the ecu & if the #'s say its within specs they dont mess with it. After thousands of miles things can change. I'll defer to the experts in here who may think otherwise though
Guest danray Posted July 9, 2007 Posted July 9, 2007 Check the rubber intake hoses for cracks. Thanks for the replys. I will check the intake system carefully. With the mc at idle and PC III hooked up, the voltage at the TPS was .414 volts. From what if have read on the forum, this is not exactly .5 volts, but is within range. If some one thinks it should be exacly on .5 volts I can set it there. The TPS has never been change from factory.
Guest danray Posted August 19, 2007 Posted August 19, 2007 I have finally taken time to reset the TPS. I set it to .503 volts in lieu of the .414 volts that I had measured. Someone, I think Greg Fields, in another topic said to set the TPS at .5 to .525 volts at idle with a PC III. It now runs significantly better with only slight "pulsing at 3k rpm and low throttle opening. I have esperienced a similar thing with FI BMWs so I can live with this. Thanks Richard for the tip.
richard100t Posted August 19, 2007 Posted August 19, 2007 I have finally taken time to reset the TPS. I set it to .503 volts in lieu of the .414 volts that I had measured. Someone, I think Greg Fields, in another topic said to set the TPS at .5 to .525 volts at idle with a PC III. It now runs significantly better with only slight "pulsing at 3k rpm and low throttle opening. I have esperienced a similar thing with FI BMWs so I can live with this. Thanks Richard for the tip. You're more than welcome Dan I had a similar issue with mine & that was the problem.
savagehenry Posted August 19, 2007 Posted August 19, 2007 Hello Danray, I have experienced that mine simply does not like RPM's in the 3K range. I stay above 4K, often 5+, and SHE loves it, shifts better, and rewards me in ways I cannot quite describe... , S.H
jrt Posted August 20, 2007 Posted August 20, 2007 Ditto. Keep the revs up- the motor is far happier above 4K.
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