Marelli fuel injection
Marelli fuel injection
Please help. I have a 97 ultra classic that has been giving me fits with idle issues. Occasionally it will ramp up to over 3000 and you can't get it to stop. Or it won't take any throttle, idles fine but falls flat when you crank the throttle. I've tried the resets of turning it off and on 3 times and unplugging the fuel pump and ecm fuses for a half hour or more. And the other day I tried the tps reset by adjusting it's position to .275 v and then running the cold idle set screw in til it's at .650 v. That worked for one day of long riding and then the next day it was back to loading up, not taking the gas, and ramping the idle back into the 3000 range. Seems like everything I try fixes it for a minute and then it returns. What gives here? Anyone have a definite fix?
Road Warrior
Joined: Dec 2012
Posts: 1,539
Likes: 692
From: magnolia tx
On auto's I'll test the tps by reading the voltage while i open and close the throttle making sure the voltage change is smooth and not jumping around, if jumping tps is faulty
Last edited by mike131; Oct 6, 2021 at 08:54 PM.
Stellar HDF Member
Joined: Jan 2009
Posts: 2,578
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From: On a Lake, not far from the Gulf
Two things come to mind. The first is what Dr. Hess mentioned. The second is a faulty Idle Speed Control Motor. After you unplugged the ECM and Fuel Pump fuses did you do the On Off thing again to synch the ECM to the ISC?
Seasoned HDF Member
Joined: Oct 2007
Posts: 8,852
Likes: 2,493
From: Decatur, Alabama
Check to see what codes you have stored in the system. If you get a code 14, you'll need to replace the engine temp sensor. The symptoms sound pretty much how they do when they're bad.
carl
carl
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From: Texas
Please help. I have a 97 ultra classic that has been giving me fits with idle issues. Occasionally it will ramp up to over 3000 and you can't get it to stop. Or it won't take any throttle, idles fine but falls flat when you crank the throttle. I've tried the resets of turning it off and on 3 times and unplugging the fuel pump and ecm fuses for a half hour or more. And the other day I tried the tps reset by adjusting it's position to .275 v and then running the cold idle set screw in til it's at .650 v. That worked for one day of long riding and then the next day it was back to loading up, not taking the gas, and ramping the idle back into the 3000 range. Seems like everything I try fixes it for a minute and then it returns. What gives here? Anyone have a definite fix?
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From:
Please help. I have a 97 ultra classic that has been giving me fits with idle issues. Occasionally it will ramp up to over 3000 and you can't get it to stop. Or it won't take any throttle, idles fine but falls flat when you crank the throttle. I've tried the resets of turning it off and on 3 times and unplugging the fuel pump and ecm fuses for a half hour or more. And the other day I tried the tps reset by adjusting it's position to .275 v and then running the cold idle set screw in til it's at .650 v. That worked for one day of long riding and then the next day it was back to loading up, not taking the gas, and ramping the idle back into the 3000 range. Seems like everything I try fixes it for a minute and then it returns. What gives here? Anyone have a definite fix?
It has unknown miles and we do not know if there are any changes from stock.
Unknown history of ownership or when the bike last operated correctly.
You report:
Idle issues. Occasionally it will ramp up to over 3000 and you can't get it to stop. Or it won't take any throttle, idles fine but falls flat when you crank the throttle.
You attempted computer reset.
From a distance and based on information provided.. it reads like engine temperature sensor.
A bad engine temperature sensor will cause bike to flip/flop incorrect temperature reading and bike will think it is ice cold and then immediately think it is very hot.
A run away idle would be a strong indicator that temp sensor is bad.