Ducati Monster Forum

Moto Board => Tech => Topic started by: Zipper on May 11, 2008, 08:08:14 AM



Title: PC III on S4 (I'm still really lean.)
Post by: Zipper on May 11, 2008, 08:08:14 AM
Currently have an '02 S4 with recently installed Arrow Hi Mount slip ons (with emissions canister removed.) It was running very lean so I purchased the PCIII. This definitely helped the bike all around, but things are still a little lean and at stop lights, I've had a few stalls with the clutch fully engaged (just dies-not really fun.) I know I can take it to a dyno shop and spend the $250 for professional map, but in the meantime, shouldn't I be able to correct this by tweaking the maps?  I seem to be idling at around 800 rpm with the cold started off. Owner's manual states this should be higher at 1,400-1,500.

1. First thought, raise the fuel ratios in throttle position 0 at low rpm's. 
2. Second though, keep the cold starter lever at roughly midpoint to keep the idle a bit higher.

Any thoughts on doing either above.  Are either of these particularly BAD for the bike?

Yes I know at some point I will get the professional adjustment (but I'm trying to keep the wife happy by not needing to spend lots of extra cash right now...  pipes + PCIII =  $$$$  ya know?)

Thanks in advance.
Zipper



Title: Re: PC III on S4 (I'm still really lean.)
Post by: Zipper on May 12, 2008, 07:22:03 AM
Ok, so I spent some more time reading up on this, and I think my problem is not so much that the bike is running lean, rather it is idling way to low.  Does this sound like a possible throttle body adjustment?  I had a full 6K service done when I purchased the bike (used with 2,800 miles on it) about a year ago.  Since then I took the emissions cannister off added the arrows and the PCIII. This started after I added the arrow hi mounts and before teh new PC III was added.

Any thoughts are appreciated.

Thanks,
Zipper


Title: Re: PC III on S4 (I'm still really lean.)
Post by: ducpainter on May 12, 2008, 07:52:09 AM
A thorough injection base set-up should cure the stalling and low idle issues.

Tweaking will be easier after that too.

Keep in mind that tweaking in the lower ranges might affect idle speed if you make big changes.


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Zipper on May 12, 2008, 08:32:06 AM
Thanks Ducpainter, in the meantime (until I get an appointment) if I use the cold starter lever to keep the idle up a bit closer to 1,100 rmps am I going to do anything "bad" to the bike?  This is my fist Duc, so I appreciate the help.
Thanks,
Zipper


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Dietrich on May 12, 2008, 08:41:16 AM
If it's not backfiring on overrun you're probably not too lean.  You can rais the idle a little by backing the air bleed screws out.  Just take it a 1/4 turn at a time and go the same amount on both sides.  You really need to get the throttle bodies synched, possibly get the throttle position sensor reset, and the PCIII mapped to take advantage of all the mods you've done.  Trust me, it will be worth it!


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Zipper on May 12, 2008, 08:51:49 AM
Yah, no backfiring, thanks.  Ahhh....the air bleed screws.  I did remove the bleeder valves and replaced them with the small 5m bolts (per the TOB.)  If I recall correctly they are not letting much air thorugh right now.  I'm going to give that a try for the time being, thanks. Zipper


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Rameses on May 12, 2008, 08:52:04 AM
In regards to your question about using the cold start lever; no, it won't harm anything.

The cold start lever is simply a high idle setting.  It's the same thing as if you were to sit at a red light with your right hand on the throttle giving it a little gas to up the engine rpm.  No problem.


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Dietrich on May 12, 2008, 11:52:10 AM
Yah, no backfiring, thanks.  Ahhh....the air bleed screws.  I did remove the bleeder valves and replaced them with the small 5m bolts (per the TOB.)  If I recall correctly they are not letting much air thorugh right now.  I'm going to give that a try for the time being, thanks. Zipper

Not really sure what you did here.... If you're talking about blocking off the nozzles that used to feed the emmision canister, replacing them with bolts is fine.  The air bleed screws are part of the metal throttle body, and may have a plastic cover over them.  Cant really block them off.  If they are screwed in all the way (or close) then you're correct- not letting much air "bleed" in.  Backing them out a tad will increase your idle, but also may cause the bike to be a tiny bit leaner (due to the exrtra air). 

Also, if you have a canned map loaded on the PCIII you can try just using the manual buttons on the box to raise the low/mid/high sections of the map without screwing up the individual throttle/RPM setpints.  Doesn't seem to affect idle speed though.


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Zipper on May 12, 2008, 01:19:02 PM
Thanks Dietrich, I was confused I did block off the nozzles that used to feed the emmision canister.  The bleed screws I have not touched.


Title: Re: PC III on S4 (I'm still really lean.)
Post by: ducpainter on May 12, 2008, 01:44:39 PM
I think you're best off using the lever to set idle and leave the rest alone.

The air bleeds will affect the whole base set up.



Title: Re: PC III on S4 (I'm still really lean.)
Post by: Dietrich on May 13, 2008, 10:08:17 AM
There's another thing to check out with the PCIII.  There is a setting under one of the tools menues that synces the PCIII tot he throttle position.  It basically sets the throttle position in the software to zero when the throttle is closed.  You might try hooking it up, starting the bike, and try resetting that.

If the bike is out of tune already, you can't really mess it up adjusting the air bleeds.  You definitely don't want to touch any thottle stop screws or throttle position sensor adjustments.  Wouldn't hurt to synch the throttle bodies though, which is also fairly easy with any kind of vacuum gauge or home made manometer.  I have used mercury carb sticks, but now have a Twinmax, it's awesome and easy to use.


Title: Re: PC III on S4 (I'm still really lean.)
Post by: Zipper on May 14, 2008, 04:24:28 AM
Thanks everyone for the assistance.  This is greatly appreciated.  I'm going to check the settings on the PC III and if needed keep the idle lever up a bit until I can get an appointment at the local shop.


SimplePortal 2.1.1