I understand that certain parameters can be set with the digital tech. I do not believe any of this can be adjusted with just the SERT software. This is why I am looking for the actual procedures. My main motivation for this information is to be able to intelligently talk to my tuner about this as it seems nobody is actually checking these on the newer bikes. However, I feel this may be part of the off idle stumble I had with the PCIII before I moved to the SERT. I am hoping that the adjustment will help with a decel pop that I have coming off of a steady 2800 rpm as well as one I have on downshift as the engines moves from 1750 back to 2300 rpm.

 

I think your question has been answered as it applies to the factory ECM, on most newer cars with Delphi ECMs there is no TPS adjustment proceedure and I am assuming thatit is also automatic forthe 07HD Delphi ECMs. When you turn the key on the ECM looks at the TPS voltage and uses that value for 0% throttle, one of reasons whythe manufactures recommendleaving throttle closed while starting. Keep in mind that the Delphi is a speed density system and the TPS signal is used mainlyfor brief accelleration fuel enrichments during an increase in a throttle movement to prevent a lean stumble, doubt if it would have any affect on your decel popping problem anyway. Now piggyback systems are a different story because they use the TPS positionto control A/F ratiosand ignition timing,but your question was limited to the factory serv manual so we wont go there.

 

Pressing the zero function button allows the ecm and tps to agree the read voltage value will be considered zero. If what you are saying is true the ecm could restrict voltage through the tps digitally. Why then would the tps have the built in resistor?

 

I know you already know this but I'll post it for the rest here. The Delphi ECM for Harley Davidson recognizes .35 to .4 milli volts as 0% throttle, if the TP voltage is out of this sensitivity it can and will effect idle, and performance or the system. I have seen several TP set higher than this from the the MOCO, installing a new Throttle body, or installing a new TP sensor. I realize there is no manual adjustment as we had in the MM system but the mounting holes do have some slop to them so the TP can be altered to achieve this required voltage....I have seen people actually enlarge the holes a couple of thousands to get theTP voltage in range. I check these settings and adjust before every tune just so I can do a better job. So gentlemen even though the TP doesn't have slots in the mounts it is necessary to have the ECM and TP talking the same language.....adjust manually as necessary

 

For 2007, the screw that adjusts the throttle position sensor has a special, tamper-proof head.

Does anyone know the name, or part number, of the tool required to fit this special screw?

Thanks

 

According to my '07 Touring Electrical Diagnostic Manual there is no adjustment to the TPS. Looking at all the diagnostic flow charts the final box after testing voltage is replace TPS or replace ECM or repair broken wire.

 

I regret not seeing this thread before now, as I just went through a lengthy (>1 yr.) diagnostic adventure with my '07 for a similar syndrome. To make a very long story short, I was getting a very intermittent misfire almost always at low-throttle cruising, generally at highway speeds. I also had idle problems, mostly high when first started. It would go away for months at a time, then return often with a vengeance, but didn't throw a code until the last two weeks when it got much worse. That code was P0122 and that linked it to the TPS. After changing plugs three times, IAC motor, wires, internal fuel-tank hardware, and changing brands of gas I finally changed the TPS. That fixed it and the bike has been running flawlessly for almost two months now. I'm very relieved, as this has been quite an agonizing journey.

There is no procedure in the manual for adjusting the TPS, but if you are having a stumble as you describe I would just replace it, as it is only $31 and is easy to change (except getting to the inside Torx bolt).

It's been three weeks since we heard from TickTock, so it would be good to hear the latest from his end.

 

LOL. 4 years on this one instead of 3 weeks! Back in the day when I was chasing down this bug, I had a problem with a spit or pop at certain rpm's that I thought may have been attributed to a bad TPS. However, I learned later that it was due to the calibration I was using in my SERT. I was running True Duals and the calibration (176pz) was using was the standard touring one. The fix was to use the one for shorty duals (176ae) (even though it was listed in the dyna/softail section). All I ended up doing was copying all the tables from one calibration to the other and miraculously the problem went away.

 

O.K., I just did the HD TT410 Bulletin (Big Twin Idle Speed Improvements) using my TTS & laptop.

Started out with no codes, but the TPS voltage was reading .70V and the IAC steps read 120 (both way too high).

Following the TT410 procedure, I set the TPS voltage for .57V and the IAC step fell to a nice value of 40.

Bike ran great for ~1 hour, then the problems (low idle/stalling) came back. Only this time, I now have backfiring (not popping ) on deceleration.

Would a funky VSS (vehicle speed sensor) cause any of this (my speedo & signals work fine)?

What should I do now, replace the TPS?

Thanks

 

The VSS can cause the speedometer to malfunction, among other things, but I don't know if it can induce misfiring, bad idling, etc. I haven't heard about this being a fix for the misfiring and bad-idle syndrome that I and others have had.

I would bet on the TPS, as if it is bad simply adjusting it as you've done won't be the long-term fix. But like I said earlier, this syndrome can be caused by numerous things, so changing the TPS is a good place to start IMO. In my case a trusted tech at my dealer suggested checking the in-tank paraphernalia first, which I agreed with and did at a stiff cost. I did have a leak but it wasn't the source of my problems, so those repairs needed to be done anyway and the money wasn't wasted.

Changing the TPS is fairly easy and cheap, so you're not out much time or money if the problem persists. Let us know how this all pans out.