2007 Road King 103" Stalling at Idle When Hot

[dolt]

The throttle idle stop screw is set up that way for the reason you cited but they have been known to back out. You can check voltage at the current position to see if it registers what it is supposed to; .60 volts fully closed. The speed sensor also tells the IAC motor when to Open/Close. When you are coming to a stop, if the speed sensor is not working properly it closes the IAC to soon and stalls the motor.

You have a PCIII so why not take it to a tuner and let a competent tuner take a look; tune while at it? I would advise against dealer downloads; they don't do much more than reset rev limiter and add a bit of fuel. A stage download will not change any settings affecting the IAC. A competent tuner will see those issues on a dyno. I think you will be led down a rabbit hole with a dealer and, in the end, spend a lot of money, still have the problem or worse. Dealers just don't have a good history when it comes to resolving EFI issues. They will most likely certainly blame any EFI issues on the PC.

 

[Rod Stewart]

Dolt; is there any way you know of to read the TPS voltage without the digital technician? It is supposed to be 0.57 volts with the throttle against the stop according to bulletin TT410.
A dealer reflash according to TT410 is supposed to fix the dying at idle when hot issue, which apparently is quite common on '07's that have the stock flash. That's why I thought I would start with that, and if it fixes that, then go from there.
There are several custom tuners in the Phoenix area; anyone any experiences to report, especially good ones?
Thanks,

"Now the question is do I get the standard 96" download and leave the PC III tuner intact, or do I get the 103" Stage II download and remove the PC III for now? Hhmmm"
I phoned Dynojet and threw this question at them. They figured reflashing with the stock 96" HD tune would be best, then add the original M812-034 PC III tune back into the mix, which is designed for 103", SE255 cams, RH true duals, and K&N AC. Otherwise I would need a custom tune, which may not be a bad thing.

 

[dolt]

Dolt; is there any way you know of to read the TPS voltage without the digital technician? It is supposed to be 0.57 volts with the throttle against the stop according to bulletin TT410.

You cannot set the TPS voltage with the PCIII; you need the SERT or TTS Mastertune. IIRC, the PCIII won't read the TPS voltage.

A dealer reflash according to TT410 is supposed to fix the dying at idle when hot issue, which apparently is quite common on '07's that have the stock flash. That's why I thought I would start with that, and if it fixes that, then go from there.
There are several custom tuners in the Phoenix area; anyone any experiences to report, especially good ones?
Thanks,

Rod, I am not an EFI guru but since one of my bikes is EFI, I have been studying up on EFI systems. The downloads I made reference to in my previous post were the "stage" downloads. Re-flashing the ECM to the stock 96" configuration should reset the TPS voltage but the tuner must re-check the IAC steps to be sure they are in the proper range or the problem will persist. The tuner should so several restarts to verify all is OK and the bike should be ridden to get to operating temps and restarted as well. If the tuner just reflashes and does not check cold and hot, you may be back at the dealer the next week.

The speed sensor I referred to in my previous post is the VSS, not the TPS. I believe the VSS runs about $50 and I think I would replace it before taking the bike to the dealer as that might be the fix. No guarantees but have seen similar idle problems fixed by replacing the VSS after guys have chased everything else when they were being told that the VSS was not the issue. After chasing everything else, spending time and $$ with no results, they replace the VSS and problem solved. You might also check for cracks in the butterfly shaft in the throttle body. That shaft has been know to crack and put the butterfly out of position which will affect the TPS operation.

If all that is OK, then the process DJ has suggested is worth a try. If that does solve the idle issue and you download the suggested map; get the motor dyno tuned; you will be glad you did. You might also consider replacing the PCIII with the Powervision or TTS Mastertune and getting that motor a proper tune.

 

[Rod Stewart]

All good suggestions dolt. I had not considered the VSS. Where is it located and how hard is it to change?

 

[dolt]

Rod,
Not saying that replacing the VSS will solve your problem but have seen replacement solve the problem for others with a similar issue. I would be more confident that replacement of the VSS was the solution if you speedo or turn signals were acting up.

#23 in the diagram; PN is 74402-05 and will run about $50 from an online discount dealer; about $60 retail from a local dealer. The location is different on your '07 than on my '02; more difficult to get to. I believe you will have to remove your right side saddle bag and side cover and you should be able to access from there. Left side may provide better access; not sure with the later model. If you are headed down the DIY road, get the HD service manual for your model; best tool in the tool box.

 

[TQuentin1]

The VSS is on top of the tranny somewhere back of the cover. It has a SHCS holding it in the port that is an allen. You'll have to chase the wire to see how they have yours routed but it should be a connector at the VSS. Should be an o-ring on the sensor part that goes into the case.

Having said that, when I replaced the 5-spd OEM tranny on my '03 UC, the SE 6-spd had the VSS on the top of the side plate. Should be able to spot it after checking out the pix below.

Cheers,

TQ

 

[Rod Stewart]

Rod,
Not saying that replacing the VSS will solve your problem but have seen replacement solve the problem for others with a similar issue. I would be more confident that replacement of the VSS was the solution if you speedo or turn signals were acting up.

My speedo and turn signals are working fine so I guess I will figure the VSS is OK for now. I do have the service manual, just had not looked at it to find the VSS yet. Thanks for the pic. Also it seems the only way to diagnose electrical and efi issues is the electrical diagnostic manual. Think I may go ahead and get one, or maybe try to find it online.
dolt and TQ; thanks for the info.

 

[HDDon]

Be sure to check for cracks in the butterfly shaft as Dolt pointed out. In one of the back issues of American Iron, Pederson showed some pictures of the cracks and said that it was something that most techs miss.

 

[Rod Stewart]

Be sure to check for cracks in the butterfly shaft as Dolt pointed out. In one of the back issues of American Iron, Pederson showed some pictures of the cracks and said that it was something that most techs miss.

Very interesting for sure!
I wonder what set of stresses would cause these shafts to crack?
They don't seem like they are seriously worked hard at all.
But wouldn't a cracked shaft result in the butterfly being positioned incorrectly, and would that not result in more idle air than normal, and wouldn't that result in an idle that was too fast? Or did I miss something?

 

[dolt]

Very interesting for sure! I wonder what set of stresses would cause these shafts to crack? They don't seem like they are seriously worked hard at all. But wouldn't a cracked shaft result in the butterfly being positioned incorrectly, and would that not result in more idle air than normal, and wouldn't that result in an idle that was too fast? Or did I miss something?

As pointed out in #22, a cracked shaft can put the throttle body butterfly in an incorrect position which will affect the operation of the TPS which, in turn, could cause the problem you are experiencing. As for what causes the cracks, who knows but if I had to guess I would lay it on the supplier; probably an off shore vendor.