Attn: PC5 Users
Cruiser
Joined: Sep 2009
Posts: 212
Likes: 3
From: SoCal
Any way you slice it, the OEM ECM is out of the loop. Even with out AT the OEM O2 sensors are connected to the PCV via the ECM connecter removed from the OEM ECM and now plugged into the PCV. The original post said the PCV shut itself down after a 2 sec warm up and the OEM ECM would take over if bike not started in that 2 sec. My problem with that is how does the OEM ECM do anything at all if not plugged into anything. I have to think if the bike starts and runs at all, quick start or delayed a few secs, it's because the PCV is doing it's job. That little whine you hear, when the ignition is turned on, is the fuel injection system pressurising itself. The OEM ECM or the PCV control the air/fuel ratio to be injected into the cylinders. That's the way I understand it and if I'm wrong well then I'm wrong. Other than it's physically still being on the bike, the OEM ECM has no bearing on how you start the bike or how it runs.
Nate
Road Captain
Joined: Aug 2008
Posts: 521
Likes: 2
From: Arkansas
Mine seems to start easier when I wait on the engine light to go out. One way may be to watch the PCV on start up and see if the lights go out after 2 seconds? We certainly need Jamie to chime in on this one, someone wake him up.
Seasoned HDF Member
Joined: Jan 2006
Posts: 11,471
Likes: 2,998
From: Charleston, SC
The two second thing was true with the PC III. Not so true with the PC-V.
The PC-V will remain on as long as you have the run/off switch at the run position.
So... if you turn the ignition switch to the on position and have the run/off switch in the run position, the PC-V will come on and never go off. You can wait as long as you want before starting the bike...
If you turn the ignition switch on and the run switch is in the off position the PC-V will come on and then go off in about 2 seconds.
As soon as you turn the run/off switch to run (which you have to do to start the bike) the PC-V comes on, initializes for a second and stays on.
So... if you are hitting the run switch and then immediately hitting the start button you could be starting your bike while the PC-V is still initializing...
Personally I think it is better to wait a second or two then start the bike, which is the total opposite of what the OP posted.
Again, the PC III would power on and then go off after the fuel circuit primed.
In that case you would start the bike as soon as you turned the run/off switch to run. PC-V...not so much.
lp
The PC-V will remain on as long as you have the run/off switch at the run position.
So... if you turn the ignition switch to the on position and have the run/off switch in the run position, the PC-V will come on and never go off. You can wait as long as you want before starting the bike...
If you turn the ignition switch on and the run switch is in the off position the PC-V will come on and then go off in about 2 seconds.
As soon as you turn the run/off switch to run (which you have to do to start the bike) the PC-V comes on, initializes for a second and stays on.
So... if you are hitting the run switch and then immediately hitting the start button you could be starting your bike while the PC-V is still initializing...
Personally I think it is better to wait a second or two then start the bike, which is the total opposite of what the OP posted.
Again, the PC III would power on and then go off after the fuel circuit primed.
In that case you would start the bike as soon as you turned the run/off switch to run. PC-V...not so much.
lp
Last edited by lp; Sep 15, 2010 at 03:37 PM.
Seasoned HDF Member
Joined: Jan 2006
Posts: 11,471
Likes: 2,998
From: Charleston, SC
Any way you slice it, the OEM ECM is out of the loop. Even with out AT the OEM O2 sensors are connected to the PCV via the ECM connecter removed from the OEM ECM and now plugged into the PCV. The original post said the PCV shut itself down after a 2 sec warm up and the OEM ECM would take over if bike not started in that 2 sec. My problem with that is how does the OEM ECM do anything at all if not plugged into anything. I have to think if the bike starts and runs at all, quick start or delayed a few secs, it's because the PCV is doing it's job. That little whine you hear, when the ignition is turned on, is the fuel injection system pressurising itself. The OEM ECM or the PCV control the air/fuel ratio to be injected into the cylinders. That's the way I understand it and if I'm wrong well then I'm wrong. Other than it's physically still being on the bike, the OEM ECM has no bearing on how you start the bike or how it runs.
Nate
Nate
That said, once you install a Power Commander, your bike will not start until the PC is powered up and initialized. This was a problem with the PC III. It would not stay on unless the fuel circuit was up. Which lead to several seconds of your starter running while the PC III came back up and initialized.
lp
Here is an excerpt from the https://www.hdforums.com/forum/touri...ml#post7272270 thread.
If you are using a Power Commander....
When you start your bike, do not wait for it to finish whining before hitting the ignition. Apparently, if the bike is turned on.. the PC5 warms up for 2 seconds then powers down. If you start the bike after that 2 seconds, you are starting up under the ECM with the original fuel/air mixture. Causing the bike to not start right, causing excess wear and tear on the starter compensator or starter clutch assembly.
According to the tech at HD, turn the bike on, then immediately start it. No warm up nesscary. Ensures the PC5 is active and the bike starts with proper mixture.
Makes sense to me.
If you are using a Power Commander....
When you start your bike, do not wait for it to finish whining before hitting the ignition. Apparently, if the bike is turned on.. the PC5 warms up for 2 seconds then powers down. If you start the bike after that 2 seconds, you are starting up under the ECM with the original fuel/air mixture. Causing the bike to not start right, causing excess wear and tear on the starter compensator or starter clutch assembly.
According to the tech at HD, turn the bike on, then immediately start it. No warm up nesscary. Ensures the PC5 is active and the bike starts with proper mixture.
Makes sense to me.
__________________
Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
Any way you slice it, the OEM ECM is out of the loop. Even with out AT the OEM O2 sensors are connected to the PCV via the ECM connecter removed from the OEM ECM and now plugged into the PCV. The original post said the PCV shut itself down after a 2 sec warm up and the OEM ECM would take over if bike not started in that 2 sec. My problem with that is how does the OEM ECM do anything at all if not plugged into anything. I have to think if the bike starts and runs at all, quick start or delayed a few secs, it's because the PCV is doing it's job. That little whine you hear, when the ignition is turned on, is the fuel injection system pressurising itself. The OEM ECM or the PCV control the air/fuel ratio to be injected into the cylinders. That's the way I understand it and if I'm wrong well then I'm wrong. Other than it's physically still being on the bike, the OEM ECM has no bearing on how you start the bike or how it runs.
Nate
Nate
Road Captain
Joined: Oct 2009
Posts: 666
Likes: 5
From: Bay Area, CA
I'm shocked! Shocked to hear this! 
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Road Master
Joined: Sep 2009
Posts: 833
Likes: 0
From: Kitimat, B.C. Canada
After changing to SE255 cams and getting a new map for my PC-v (no AT) from Jamie @ Fuelmoto, I experienced rough starting (took a couple of seconds and a few cranks).
Talked to Jamie and he recommended starting it immediately after turning on the ignition. Something about the fuel pump ...?
I tried it and it worked. Starts up right away without cranking over a few times first.
So, now I turn on the ignition (I never turn off the kill switch) and hit the starter right away. No problems since.
Talked to Jamie and he recommended starting it immediately after turning on the ignition. Something about the fuel pump ...?
I tried it and it worked. Starts up right away without cranking over a few times first.
So, now I turn on the ignition (I never turn off the kill switch) and hit the starter right away. No problems since.
Road Master
Joined: Aug 2005
Posts: 1,098
Likes: 5
From: North Texas
Fuel Moto to the Rescue, As always Jamie, thats for clearing the air.
And if I can say so myself, why not the next time this comes up just go straight to Fuel Moto for the answer's?
I know Harley engineerd and built the bike's but these guys know how to make them run, Period.
And if I can say so myself, why not the next time this comes up just go straight to Fuel Moto for the answer's?
I know Harley engineerd and built the bike's but these guys know how to make them run, Period.