My truck mis-fires whenever I turn on cruse.
Hi Ray. Is there anything else you can tell us about your vehicle and the problem you’re having so someone here might be able to help you?
Truck runs great. Have replaced plugs, plug wires and distributer cap. For example, driving down the road at 60 mph (or any speed), turn the cruse control on, and press button to hold speed. The truck immediately starts mis-firing (or so it feels). Turn cruse off and truck immediately goes back to running very smooth. Have about 145,000 miles on it. Used cruse to drive to work every day until about 130,000 miles when this problem started. Everything else on truck runs great. Don’t know what else to tell you. Thanks for any suggestions.
I think this truck still uses vacuum to drive the servo that controls the throttle. I suspect there is a vacuum leak in the line running to the cruise control servo or in the fitting or even the valve itself. The lean condition from a vacuum leak will cause a miss.
Thanks. I will see if I can figure out where this line is and check it out.
Does the tachometer flutter a little when you feel this disturbance?