In lieu of doing basic maintenance of my truck, or finishing a million other half done projects, I've dove balls deep in to trying to convert my cruise control to double as a hand throttle to hold RPM. While a hand throttle or bike shifter and a cable would work fine, I liked this idea better. The goal is to be able to use cruise to bump up RPM with the cruise actuator for times when I'm winching, or th
So far I have disabled the clutch switch, and the two switches (N/O, and N/C) on the brake pedal. Also, I've cut the speed signal input and replaced it with a wire I tapped off the ignitor to use as the engine RPM signal.
All seems to work fine while driving with load on the engine. I can clutch and brake and cruise continues to work (until about ~3000 RPM where the cruise ECU sees an "over speed" and shuts off => wiring manual says that is ~200km/h). The problem I have is sitting still with no load on the engine. Sitting at idle, turning on the cruise the issue is as follows:
In the end, its like I'm sitting there in neutral bliping the throttle every 3 or 4 seconds. Not sure exactly how the cruise ECU is working, but it's almost like a proprietary controller that has way too much gain and is just "hunting" for its set point but way overshooting on either side. Or at least that's the little I remember of PID's. I was hoping the actuator was a servo motor that could easily have its control wiring changed, but after opening it up I think its some kind of stepper motor (although all 4 leads coming off of it seem to have continuity so..?). Anyone have any suggestions on how to move forward. Wiring from the factory manual posted below, although the ECU and actuator(motor/solenoid) are all in package, not separate as shown.
So far I have disabled the clutch switch, and the two switches (N/O, and N/C) on the brake pedal. Also, I've cut the speed signal input and replaced it with a wire I tapped off the ignitor to use as the engine RPM signal.
All seems to work fine while driving with load on the engine. I can clutch and brake and cruise continues to work (until about ~3000 RPM where the cruise ECU sees an "over speed" and shuts off => wiring manual says that is ~200km/h). The problem I have is sitting still with no load on the engine. Sitting at idle, turning on the cruise the issue is as follows:
- turn on cruise control
- hit accelerate on the cruise stick to raise idle
- actuator opens throttle body
- RPMS rise way past "set point"
- cruise ECU sees its above the set point
- actuator closes throttle body
- RPMS drop back down to idle
- cruise ECU sees its below the set point
- actuator opens throttle body
- RPMS rise way past "set point"
- continue revving engine up and down forever in Walmart parking lot
In the end, its like I'm sitting there in neutral bliping the throttle every 3 or 4 seconds. Not sure exactly how the cruise ECU is working, but it's almost like a proprietary controller that has way too much gain and is just "hunting" for its set point but way overshooting on either side. Or at least that's the little I remember of PID's. I was hoping the actuator was a servo motor that could easily have its control wiring changed, but after opening it up I think its some kind of stepper motor (although all 4 leads coming off of it seem to have continuity so..?). Anyone have any suggestions on how to move forward. Wiring from the factory manual posted below, although the ECU and actuator(motor/solenoid) are all in package, not separate as shown.
