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Discussion Starter #1
Why do the FI TC-88 bikes idle so rough when they have a Power Commander installed ? I have the Stage II flash (88") and the bike idles OK but when I connect the PowerCommander (PCIIIr) it idles like it is going to shake apart. It smoothes out fine just off of idle. I have played with the zero throttle position cells with no change. Any thoughts ??

dick - peoples republiK of chino
 

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The EFI bike uses two tables in the ECM to control the idle speed. One is the idle/temp table which sets the idle based on ambient temperature roughly 1300RPM falling to 1100RPM as ambient temperature rises from 32F to 95F. The range is bigger but you get the point. The second table is the Idle Air Control which increments/decrements the air fuel via an electric valve based on the operating temperature of the motor. This manages idle while the bike is warming up. These two tables are for idle control only - 0% throttle position. As soon as you open the throttle, then these are not used but now Warm up enrichment (a third table) kicks in.
My guess is the PC you installed is in conflict with the ECM or IAC valve on at least two of these tables. It would be interesting if your problem idle goes away when the bike is fully warmed up?
 

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Discussion Starter #3
tsuter said:
The EFI bike uses two tables in the ECM to control the idle speed. One is the idle/temp table which sets the idle based on ambient temperature roughly 1300RPM falling to 1100RPM as ambient temperature rises from 32F to 95F. The range is bigger but you get the point. The second table is the Idle Air Control which increments/decrements the air fuel via an electric valve based on the operating temperature of the motor. This manages idle while the bike is warming up. These two tables are for idle control only - 0% throttle position. As soon as you open the throttle, then these are not used but now Warm up enrichment (a third table) kicks in.
My guess is the PC you installed is in conflict with the ECM or IAC valve on at least two of these tables. It would be interesting if your problem idle goes away when the bike is fully warmed up?
Thanks for the input.

No, the idle is still rough when bike is warm. I have tried different settings of the TPS with no change. The TPS is now set at 240 mv with cold idle arm removed and throttle plates pushed into the throttle bores and warm idle backed out. As I said, with just the Stage II flash and no PC, the idle seems fine.
 

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I tune my ECM directly with the EFI Tuner and don't really know the PC but it still seems like something is in conflict. The IAC valve which is an electric threaded stepper valve gets incrementally opened and closed as the ECM trys to set the idle speed according to the table parameters. Seems like it is getting a faulty signal when the PC is attached.
I'm sure there are a bunch of PC folks out there who will maybe have some ideas. I'm assuming you are not getting a check engine light when the PC is attached.
 

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Since you can adjust the TPS it must be a Marelli bike.

Two problems right off the bat. TPS should never read 240mV, once you lose the factory adjustment by playing with it the default setting with everything backed off is 275mV. Readjust the cold idle to the values in M1105 and the hot idle.

Then go into the advanced mode on the PCIIIr software and perform the throttle position learn. The PCIIIr needs to know where 0 and 100% throttle is.

Haven't looked at the MM PC maps for a while, but there used to be very few maps for a stage II flash ECU. Odds are you have the wrong map in it.
 

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Discussion Starter #6
HIPPO said:
Since you can adjust the TPS it must be a Marelli bike.

Two problems right off the bat. TPS should never read 240mV, once you lose the factory adjustment by playing with it the default setting with everything backed off is 275mV. Readjust the cold idle to the values in M1105 and the hot idle.

Then go into the advanced mode on the PCIIIr software and perform the throttle position learn. The PCIIIr needs to know where 0 and 100% throttle is.

Haven't looked at the MM PC maps for a while, but there used to be very few maps for a stage II flash ECU. Odds are you have the wrong map in it.
Good input Hippo...many thanks. I have tried different values for the initial TP setting but never as high as 275 mv. I will try that value and see what happens. Right now, my warm idle voltage is about 515 mv....I haven't checked the cold value. All the cold idle functions appear to be correct. Bike starts out with about 1300 rpm at cold idle and then drops to just under 1000 as the motor warms up.

I have set the TP on the PCIIIr for 0 and 100 percent throttle.

As far as maps go, I am using a custom map that seems to do OK. I have set the F/A at 13:1 and have achieved 81.5 HP and 90 TQ. This is with a 88" with SE Air Cleaner, SE-203 cams, Bassani Power Curve exhaust and the PCIIIr. I am happy with the numbers and performance...just the idle sucks.....:mad:
 

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Discussion Starter #8
Kampnnut said:
I'm wondering if a leak around the intake manifold would be part of the problem?
I thought of that and did the WD-40 check with negative results... thanks for the suggestion tho. I should point out that I have seen this idle problem on many bikes with the Power Commander installed. It is not just on my bike. I think the suggestion by Hippo to raise the TP voltage to 275 might help. I set mine lower due to info I got form other forums.
 

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Chinorider, I just got my bike from the shop with a PC111. It seems to idle rough as well. Might not have foscused on it if not for your thread. I plan to get a custom map when its broken in so I'll let you know. btw, the power curve looks great, dealer installed it "free" since the factory headers were off.

greg
 

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Discussion Starter #10
gbenner said:
Chinorider, I just got my bike from the shop with a PC111. It seems to idle rough as well. Might not have foscused on it if not for your thread. I plan to get a custom map when its broken in so I'll let you know. btw, the power curve looks great, dealer installed it "free" since the factory headers were off.

greg
I am beginning to believe that is just the nature of the beast (PowerCommander). I tried to get in touch with Mike Daniels at Dynojet to discuss the issue but he was unavailable. It really isn't a big deal IMHO but I was just wondering what might be the cause.
 

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Put about 300 miles on today. Clearly a rough idle, reminds me of when I used to hold the front brake on at idle and it would somehow make the bike shake some.

I plan to get a custom map early next week, and will point out the rough idle. I'll let you know if the custom map helps.

ps, please post if you figure it out as well, thanks,

greg
 

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2002 Ultra, and slight rough idle with smoke

Same problem, slight rough idle, but only when cold, and smokes slight on throttle burst when cold.... i wrote power commander and got a reply, on 2002-2003 touring models, the PC is active right from the start, meaning older versions didnt kick in until the cold idle from the factroy ecu was done.. then the pc took over.. now the pc is active right from the start, and the harley ecu is kickin in that little extra for cold conditions... ive asked about a solution.. but havent heard back yet. In my eyes... its either lower the values and reduce roughness and smoke on cold idle, or live with it and keep the power..... but then again... im just learning ...
 

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I have the power commander 111 installed in my 01 road king with excellent results. After I installed the stage one intake and wild pig pipes it ran like crap, but now with the PC it runs great right up to the rev limiter. It back fires on deceleration more than it should so Millers cycle center in Daytona is going to re-map it to illuminate that. Does anyone know if too low of an idle will hurt the motor?
 

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Does anyone know if too low of an idle will hurt the motor?
Yip!!!
Might sound better (potatoe potatoe). Vibrate more but in the long run, not good.
 

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I have idled it down to 700 RPM when it is warm and it hardly can be heard running and it doesn't vibirate. The oil light stays off so I know I have at least a few pounds of pressure. This is a EFI engine and I didn't think I could bring it down that low. So far all I have heard about potential damage is speculation. The normal idle might be set higher from the factory due to emmission concerns instead of any other reason. I am still searching for a logical mechanical reason not to keep the RPM that low.
 

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What can't be? I am not getting any generator lights either and at night the lights are not showing any dimming, but if the charging is affected it would only be for short durations while setting at a traffic light.
 
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