Bike is a 2000 FLHRCI with the dreaded M&M injection. Mods are stage 1 intake, 2-into-1 exhaust and pcIII. Bike stumbles off-idle or anytime I blip the throttle. After about 1800 rpm it pulls strong. Rear plug is also sooted up pretty bad. Gas mileage is down around 32-34 mpg. Started having the hesitation problem shortly after I installed PCIII but not immediately after so I'm not sure if its the cause.

Have replaced plugs, cleaned air bleeds in throttle body, cleaned air filter, and also tried several different pcIII maps with no luck. Plan on checking for intake leak soon but figured I would ask around for an ideas on what could be cause of these symptoms??? Thanks guys

 

Mine did the same thing with the PCIII. Took it off and installed the Cobra FI2000R AutoTune with CVT (Constant Variable Tuning) and hesitation is gone, mileage back up to 40 to 42 and still pulls like a freight train.

 

Well some-bitch. I should also mention that I updated the firmware on the PCIII which was supposed to cure the "hesitation" problem. Might be time to yank the PCIII and see what happens. Any other thoughts? BTW thanks for the reply bodean

 

Check the throttle shaft for wear, see if it wobbles at all, his could affect the tp sensor, also the sensor itself could be heading south.

 

Can't run it this way for long, but I'd bypass the PC III for a few miles and see if that's the cause. My 95" Factory Stage II (MM Injection with HD download,) never hesitates off idle when warm. in fact it has always performed flawlessly.

( Just don't ask me about it's cold idle behavior. That still sucks...)

 

My '01 with M/M ran like a scalded dog after a stage II with Andrews 26's and a Cobra FI2000, didnt have the auto tune back then.
I ran that combination year-round for over 50K and it never stumbled... averaged in the low-mid 40's on gas...

 

Thanks fellas. I checked for an intake leak and I'm good there. The more I troubleshoot this, the more I notice that the bike hesitates much more when the motor is warm.

The bike does have a stage 1 download so I'll be fine to run without the PCIII. I scored a sweet deal on the PCIII so I figured I'd throw it on for the hell of it. Ended up yanking it yesterday and I hope to get some riding in today to see if that fixed the problem.

Also plan on checking the throttle shaft and tps

 

An air leak will create a lean Air Fuel Ratio so will not soot the plug. You said this happened after installing ther PCIII? Where did you get your map? Sounds to me like you sooted the rear plug over time and now have the buildup fouling the plug.

Easy short term fix would be to replace the plug but your map is not correct for your build and the new plug will foul again. If you dont have access to a dyno with O2 sensors you will need to work through the various throttle positions and engine RPM's to understand where your setup is running rich. Just a note, if the bike in your thread is the one we are talking about, the blue pipe is an indicator of a rich system, the farther back the pipe the richer the AFR. FYI, Gold indicates a lean condition.

Just looking online, and your picture, seems the 2 into 1 exhaust should be similar to the thundeheader which is 2 into 1. The following 2 programs from Dynojet are the same but 1 is for a stock ECU and the other is for a bike that has had the stage 1 downlod. I would compare them to what you have loaded on your bike.

802-023 = Stock ECU, Thunder Header & SE Air Cleaner
802-024 = Stage 1 ECU, Thunder Header and Se Air Cleaner

The Dynojet software is free to download, these 2 programs are free to download, and if you have a USB to mini cable that can be purchased at radio Shack you can get the program off your bike.

Save the program off your bike,install whichever program above is for your build, change the plug and try it out.

 

Scrmnvtwins,
Yes I started having the hesitation problem after the PCIII was installed. I got the map from the Dynojet website and I'm actually using the Thunderheader w/stage 1 AC and download as you suggested. I have also tried the V&H Pro Pipe w/stage 1 AC and download.

While I believe the tune is probably responsible for my rich condition, I'm not the sure that it is causing the hesitation issue. I actually did edit the map in the lower rpm ranges (1000-1600) to lean it out a little in case the motor was getting bogged down by too much fuel. Bike still hesitates. I plan on disconnecting the PCIII for now to determine if it is responsible for my hesitation issue.

 

You may also consider resetting the PCIII under environmental Options then reloading the program. If you have issues with stumbling you may simply need to enable the Accelerator Pump Option. I did this on my '03 which allows me to pump a little extra fuel when I crack the throttle but, run lower numbers in the map to keep a leaner map. Basically I overcame stumble cold or ping hot by enabling and programming the accelerator pump utility. You need to download the utility and enable it on your desktop before you can enable it on your PCIII