Low idle/stall HELP!
2nd Gear
Joined: Jun 2016
Posts: 6
Likes: 0
From: Stl
Okay so here is my theory, PCV is sending me a new unit warrantied. But while I've had my bike opened up without my tuner it of course has been running extremely lean. So, I'm thinking its a safety my bike is doing, since it's running so lean it's getting a lot hotter than it usually would, so when it gets hot it goes into safety, TPS and IAT codes go off and bike shuts down. Once my bike is cooled off and is safe for itself to operate, it fires back up as if nothing is wrong. When I get my commander back the end of the week I'm going to test this theory out and see if just getting it not leaned out will solve my problems.
Outstanding HDF Member
Joined: Feb 2015
Posts: 2,414
Likes: 433
From: Arkansas
There are 3 modes that the computer will operate the fuel mixture in depending upon temperatures read at the temp sensor in the head. These are at 320F the ECM will reduce idle speed to cool down, at 338F the ECM richens the mixture to add extra cooling, and at 356F the ECM which stops the fuel injector pulses to attempt cooling. Should either of the latter 2 modes go into effect the IAT or the TPS codes should not be happening. I would give the 2 components the full test that they need to determine if one or the other is faulty otherwise look at the ECM itself. There is a published test in the service manual to determine if they are faulty. P0113 indicates that the IAT is either open or high resistance and the P0123 indicates that the TP has high resistance. I would look at the harness as well, maybe when the engine is hot it is causing issues in the harness. I would check the black/white striped wire coming from the TP as the IAT is also tied into the same wire going to the ECM (5V Sensor Ground). This same wire supplies the ground for the MAP and the Engine Temp sensors as well, main connector to the ECU may be a good place to start looking, if nothing else use the multi-meter and check continuity between that pin (pin 26) and the wire on each of the sensors, maybe there is a recessed pin or a loose connector somewhere.
Last edited by Zanthamos; Jun 20, 2016 at 12:44 AM.
Thread Starter
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Stage IV
Joined: Feb 2016
Posts: 4
Likes: 0
From: Florida
Found the problem
2003 Heritage Softail EFI 58K miles, Andrews 26's PCV SE II slip ons and intake. Been having a problem where the bike will run fine no speedo issues or anything else but out of no where it starts idling real low and sometimes will stall when i pull the clutch while rolling to a stop. I read a bunch of different forums which promted me to clean and change the Idle Air Control but that didnt fix it either. Anyone have any advice? I was thinking of chasing this rabbit by changing Vehicle speed sensor and engine temp sensor.
Outstanding HDF Member
Joined: Feb 2015
Posts: 2,414
Likes: 433
From: Arkansas
So my guy couldnt stand that he couldnt find the problem so he kept at it. During his chase he tighten the primary chain which is when he found out that the compensator nut was loose causing the bike to loose voltage. This was then causing it to idle low and stall some times. Hope this help some one that may have the same problem I know it could have saved me about $60-70.
2nd Gear
Joined: Jun 2016
Posts: 6
Likes: 0
From: Stl
There are 3 modes that the computer will operate the fuel mixture in depending upon temperatures read at the temp sensor in the head. These are at 320F the ECM will reduce idle speed to cool down, at 338F the ECM richens the mixture to add extra cooling, and at 356F the ECM which stops the fuel injector pulses to attempt cooling. Should either of the latter 2 modes go into effect the IAT or the TPS codes should not be happening. I would give the 2 components the full test that they need to determine if one or the other is faulty otherwise look at the ECM itself. There is a published test in the service manual to determine if they are faulty. P0113 indicates that the IAT is either open or high resistance and the P0123 indicates that the TP has high resistance. I would look at the harness as well, maybe when the engine is hot it is causing issues in the harness. I would check the black/white striped wire coming from the TP as the IAT is also tied into the same wire going to the ECM (5V Sensor Ground). This same wire supplies the ground for the MAP and the Engine Temp sensors as well, main connector to the ECU may be a good place to start looking, if nothing else use the multi-meter and check continuity between that pin (pin 26) and the wire on each of the sensors, maybe there is a recessed pin or a loose connector somewhere.
Seasoned HDF Member
Joined: Jun 2015
Posts: 10,284
Likes: 7,766
From: West Central FL
Highjackers are worse than oil threads. At least the O.P. seems to have gotten his stuff squared away.
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