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Classic/Antique Car Repair/miss fire
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Question
I have an all original 1929 Graham Paige. Car runs great but when you turn on the headlights and the motor is pulling hard, hills or high speed it will misfire. If you turn the headlight off it will run and pull perfect. Any ideas?
Thanks,
Scott
I would check the charging voltage with the lights on and the engine at road speed. If the voltage is low, below 6 volts, the generator system is suspect. This will limit the voltage available to the coil to fire the engine under load. If the voltage is ok then move the voltage to the + side of the coil. Repeat the test. If the voltage is low when the lights are on then there is resistance in the circuit between the battery and the coil, again lowering the voltage to the coil and causing the problem. Let me know the results and we will go from there.
Brad
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Answers by Expert:
Brad Sears
Expertise
All automotive including antique and collectible. However if the car has been modified I can only answer in general terms and maybe get you pointed in the right direction.
Experience
Automotive tech instructor.
Syndicated auto columnist 1970's though the early 1990's.
Syndicated auto radio talk show, Ask Brad About cars, CBS Radio 70's through 90's
TV Show "Last Chance Garage" 1980's PBS-TV syndicated.
Auto instructor for the following companies:
Fram
Autolyte
Holly
Carter
AMF
Ford Motor
University Of Conn
Blue Hills Technical School
Sugar River Technical Center
Grew up in a family garage in Needham Mass and turned wrenches from the age of 14.
Publications
Manchester Union Leader, Nashua Telegraph, Motor Service Magazine, Yankee Magazine, Popular Mechanics (Saturday Mechanic early 80's), Los Angeles Times, New York Times, and lots more.
Education/Credentials
More than I care to remember.
Basically Franklin Technical Institute in Boston, Northeastern University, Fitchburg State Teachers College, Tufts University, and a lot of factory schools along the way.
Awards and Honors
Moto Award winner. And much more.
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