I could really use some ideas here guys. Bike is a 2001 roadking with the M&M efi, PCiii. I know this is kinda long, but I'm trying to give as many details as possible.

Bike was running just fine on a Friday.

Had the throttle position sensor replaced Saturday morning because I knew it was acting up every now and then, and I was scheduled for a tweak on the dyno the following Tuesday. Had to have the local dealer do the swap because I had no way to read the voltage on the TPS to set it right. Rode the bike home from the dealer and didn't notice any issues, but I had the radio wide open. Followed a friend part way home a few hours later and returned home myself, again with the radio blasting. Hooked the bike up to the computer just to verify the throttle position sensor was working right. Noticed the idle was a little low, so I adjusted it up a bit. Cleaned the trottle body while I had the air cleaner off, and parked the bike for the night.

Next day (Sunday) me and the wife jump on it, get about 4 miles from home, come to a stop at a stop sign and the bike hangs at 2k rpm's. Bike is also decel popping like a ****** f*cker. If you roll the throttle hard at idle, the rpm's drop just fine until they get to 2k, then either stick completely, or hang momentarily before settling back to idle. Same thing while gearing down to a stop. Bike isn't idling just right either. It will spit back through the intake every now and then. Turned around and went home to try and diagnose the issue. Can't find anything obvious. Made sure the throttle cables weren't sticking, etc. Also noticed that when you first start it, the idle doesn't raise slightly, then drop back down. Leaves me scratching my head......

Monday I ride back to dealer, tell them the problem. They say it has nothing to do with what they did. They say all they did was set the voltage on the TPS. They blame it on the PCiii. Of course..... I get pissed and walked out. I call and reschedule my dyno appointment for Wednesday, so I have an extra day to try and figure out the problem. No sense in hauling the bike 8 hours if it's f*cked up. My tuner tells me the TPS has to be "in sync" with the PCiii, and that's probably what's wrong.

Tuesday morning I ride it to another delaer. It's cold as hell outside, temp is around 40*. Bike runs really good on the way there. Doesn't seem to be decel popping very bad, and I don't remember the rpm's sticking like before. Asked the dealer to hook it up to the digitech and check that the TPS was set right by the first dealer. They said the voltage was right, and there were no codes showing. Bike runs so-so on the way home. Not as good as on the way there, but better than the day before. I load it up and drive to Florida that afternoon.

Wednesday morning my dad and I make the hour ride to the tuner's. Bike is decel popping like hell, idle spits every now and then, and the rpm's are hanging again. Tuner puts it on Dyno, adds gobs of fuel to the the map and cures the decel pop. But he had to add WAY more fuel than should have been added. The bike was already tuned from last year, so he shouldn't have had to make any changes there anyway. It hangs at 2k rpm's on the dyno, and he checks for an intake leak. There is a slight leak. I take it for a test ride and decel pops are pretty much gone, but it hangs at 2k rpm way worse than before. He tells me my IAC is acting up, and that my cold idle needs to be adjusted. He also tells me that everything is "in sync", but that PC's are notorious for changing themselves over time.....

Dad and I leave, and do some riding the rest of the day. Every time I come to a stop, the rpm's want to hang at 2k. The only way to get them to drop is to ease the clutch out in gear while holding the brake. Basically bogging the bike down. I load the bike back up that night, and head back home.

Since I came home, I fixed the slight intake leak. I also put the original map back in. Bike is decel popping like hell again, spits at idle every now and then, and still hangs just a little at 2k rpm's. I've disonnected the PCiii, and the bike still spits at idle, and still acts like it wants to hang a bit. Revving it up I still get a bit of decel popping that I'm sure would be worse if I was actually riding it. My motor is so far from stock that I haven't bothered trying to ride it without the PCiii. I know it's not gonna run right without it. When first started up, the bike still doesn't idle up slightly like it used to, then settle down. So I disconnected the IAC while it was running. This is supposed to fool the bike into thinking it's cold, and the rpms should jump up. The idle doesn't change at all. I'm pretty sure the AIC is related to the throttle position sensor, right?

All this started the day after the TPS was changed, so my first thought was that the problem was related to that. And it may still be. I had a second dealer (supposedly) confirm the settings were right, so now I'm not so sure it's related. I could really use some ideas here. I can't afford to just start throwing parts at it, and I really don't want to take it to a dealer and pay them to diagnose something that they can't find..... I'm almost ready to just convert the damn thing to a carb. I know the M&m system has a bad rap, but mine has been flawless up til now. If it's something easliy fixed, I'd just as soon keep it. But if it's gonna cost a bunch of money and end up with me needing another dyno tune, I'll just go with a carb and not have this issue again down the road.

Any ideas?

 

That was quite a read. As I was going through it, I kept thinking you had a head temperature sensor problem but you said you had no fault codes so that probably isn't it. Repost your question down in the EVO section, lots of guys with M&M EFI bikes there. I do know that M&M bikes don't work well with motor upgrades and there have been many idle issues fixed by resetting the ECM.

Right now, the IAC in my bike (98 RCK) isn't working. It's stuck. When I cold start it, I have no problems other than a really low idle. I just throttle up and put the throttle lock on while it's warming up. The bike runs fine like it is but I'll replace it when I get around to it.

 

Mine has been fine for a year with all the upgrades. My IAC moves back and forth when you cut the switch on/off, but the idle doesn't seem to raise like it used to/should do. The fact that I can unplug it and the idle didn't change leads me to believe something isn't working. I also wondered about the temp sensor since it seemed to run pretty good when it was cold as hell outside.

 

That was quite a read. As I was going through it, I kept thinking you had a head temperature sensor problem but you said you had no fault codes so that probably isn't it. Repost your question down in the EVO section, lots of guys with M&M EFI bikes there. I do know that M&M bikes don't work well with motor upgrades and there have been many idle issues fixed by resetting the ECM.

Right now, the IAC in my bike (98 RCK) isn't working. It's stuck. When I cold start it, I have no problems other than a really low idle. I just throttle up and put the throttle lock on while it's warming up. The bike runs fine like it is but I'll replace it when I get around to it.

 

Try the simplest solution first. Have you cleared the ECM memory since the TPS was replaced? Unplug the battery for an hour or so. Then hook the battery back up. Handle bar switch to "Run". Turn the key switch to "On" for 5 sec. (two seconds after fuel pump stops), then off for 10 sec. Repeat. You can get the voltage off of the TPS without a breakout box. Unplug the TPS. Stick a small solid wire down the grey/purple wire. Test to make sure that you have made contact with the connector. Plug the TPS back in. Attach the (+) lead of a DVOM to the bare wire you slid along the grey/purple wire. Attach your (-) on DVOM to ground. With the Engine Stop/Run Switch in the RUN position, turn the Ignition Light/Key Switch to ON. While observing TPS voltage, turn the Ignition Light/Key Switch back to the OFF position. Note that the TP voltage drops, increases and then stops just before electrical power is interrupted. Note the voltage it stops at. Adjust the torx screw on the T10 cold idle screw until the DVOM is between the voltage in the table below for your bike.
1340 Domestic/HDI 0.61 to 0.64
1450 Domestic/HDI 0.64 to 0.68
If you can't set the voltage your IAC is probably bad.

It could also be the head temp sensor. Sometimes they will not throw a code. I don't have a test for that.

 

I tell ya what I converted my '01 FLHTCI to a carb never looked back.

 

Larsfum, thank you for telling how to get around the break out box. I just fooled with it some, and it seems I made a nice improvement. I'm gonna run through the book procedure and check everything again. The voltage was definitely off though.

 

You said you adjusted the idle up just a bit. How did you do that? If you adjusted the idle screw on the throttle body, I would suspect that.
I had to install a new throttle body due to a drop and cracked throttle body. The idle screw on the new throttle body was not adjusted. For over a year, my bike had terrible decel pop and at times it idled so low it would die.
I took it to two different dealers and they both could not find any problem. No codes or anything to troubleshoot. I told both dealers I had replaced the throttle body and they both said the idle screw adjustment was fine.
Finally, I decided to try adjusting the idle myself. Through trial and error, I found the sweet spot and no more decel pop and it never died on me again.
Another time, I had some problems with spitting and sputtering and muffler pops.
The dealer found low fuel pressure due to a pinhole on the fuel line inside the tank on the high side of the pump.

 

Wife and I just went for a short ride. It's much better now. Bike idles much better, with no spitting back. Very little decel pop, and doesn't do it constantly like before. It definitely seems the problem was in the voltage settings and the idle adjustments. I'll run through the complete procedure tomorrow, and hopefully get it perfect, but right now it's time for a beer or 3. Today is my b-day, and getting this thing figured out was the perfect present.

 

Good to hear that things are getting better. Make sure that you reset the ECM after setting the idle or TPS voltage. This is the procedure that I followed, and it worked great.
http://www.harley-heaven.com/M1105_idle_speed_MM.pdf
BTW Happy Birthday