Issues w/ stalling and ?'s on an ECU swap
Additional research suggests that the IAC module itself is the predominant cause of this issue (especially for the '07 models).
It's only a $50 part, which is far better than a new tuner and/or a new ECU!
Swapping this part out myself will still be cheaper than the hour+ labor for a shop to just diagnose it, and it will be new; so even if it isn't the root cause, I'll be ahead...
It's only a $50 part, which is far better than a new tuner and/or a new ECU!
Swapping this part out myself will still be cheaper than the hour+ labor for a shop to just diagnose it, and it will be new; so even if it isn't the root cause, I'll be ahead...
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Banned
Joined: Aug 2021
Posts: 4,027
Likes: 6,286
From: SoCal
Yes, but the screw position will affect idle speed at all times, not just when returning from higher RPM's.
It idles fine when started, just not when coming to a stop, so all indications that can find point to a sticking/failing IAC.
I have cleaned it multiple times and there has been no change in performance, hence the liklihood that it is the root cause (or at least part of the root cause).
It idles fine when started, just not when coming to a stop, so all indications that can find point to a sticking/failing IAC.
I have cleaned it multiple times and there has been no change in performance, hence the liklihood that it is the root cause (or at least part of the root cause).
Yes, but the screw position will affect idle speed at all times, not just when returning from higher RPM's.
It idles fine when started, just not when coming to a stop, so all indications that can find point to a sticking/failing IAC.
I have cleaned it multiple times and there has been no change in performance, hence the liklihood that it is the root cause (or at least part of the root cause).
It idles fine when started, just not when coming to a stop, so all indications that can find point to a sticking/failing IAC.
I have cleaned it multiple times and there has been no change in performance, hence the liklihood that it is the root cause (or at least part of the root cause).
if the IAC were stuck it would idle higher as it warmed up. You say it starts fine and idles fine except for decel.
Last edited by Ed Ramberger; Nov 8, 2021 at 02:34 PM.
Road Master
Joined: May 2008
Posts: 1,232
Likes: 428
From: Northern NY
ECUs do hold the VIN and miles covered amongst other things.
Have you checked the IAC is working properly against the electrical diagnostic manual?
Put a stock air cleaner on and remove the power commander. ECM already holds stock tune I believe as PC is a piggy back device?
Have you checked the IAC is working properly against the electrical diagnostic manual?
Put a stock air cleaner on and remove the power commander. ECM already holds stock tune I believe as PC is a piggy back device?
Seasoned HDF Member
Joined: Sep 2008
Posts: 14,160
Likes: 11,249
From: San Diego, CA
In 2019, I converted my 2002, FLHTC (carbed) to Delphi, EFI from a donor 2002 FLHTCI. Switching the ECU was a none issue with the vin# and my bike. I was concerned about it but it was fine. Converted the donor to carb and installed my carbed ECU and ignition in that bike.
For an owner to switch an ECU, particularly if you did not have a TSSM (security) and only had a TSM... was easy with early twin cams....
IIRC, I believe it was 2004 when there were some changes made to the speedometer/ECU/TSSM interface.... There were user available procedures to marry TSSMs, TSMs, and ECUs together, but they were time consuming and needed to be very precise in execution...
Then in 2006/2007 the bikes switched from the TSSM to the HFSM (hands free security module) and from an ECU (open loop EFI) to an ECM (closed loop EFI), things became even more complicated....
Currently with Canbus and BCMs.... it is impossible for an owner to change their ECMs, without dealer assistance, unless they have the proper computer diagnostic tool ($$$)...
Road Master
Joined: May 2008
Posts: 1,232
Likes: 428
From: Northern NY
For an owner to switch an ECU, particularly if you did not have a TSSM (security) and only had a TSM... was easy with early twin cams....
IIRC, I believe it was 2004 when there were some changes made to the speedometer/ECU/TSSM interface.... There were user available procedures to marry TSSMs, TSMs, and ECUs together, but they were time consuming and needed to be very precise in execution...
Then in 2006/2007 the bikes switched from the TSSM to the HFSM (hands free security module) and from an ECU (open loop EFI) to an ECM (closed loop EFI), things became even more complicated....
Currently with Canbus and BCMs.... it is impossible for an owner to change their ECMs, without dealer assistance, unless they have the proper computer diagnostic tool ($$$)...
IIRC, I believe it was 2004 when there were some changes made to the speedometer/ECU/TSSM interface.... There were user available procedures to marry TSSMs, TSMs, and ECUs together, but they were time consuming and needed to be very precise in execution...
Then in 2006/2007 the bikes switched from the TSSM to the HFSM (hands free security module) and from an ECU (open loop EFI) to an ECM (closed loop EFI), things became even more complicated....
Currently with Canbus and BCMs.... it is impossible for an owner to change their ECMs, without dealer assistance, unless they have the proper computer diagnostic tool ($$$)...
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