PCIII USB

[quazi-moto]

Anyone try the accelerator pump utility in their PCIII? Can it be tweaked to tame the dreaded lean midrange condition that seems to be inherent in the 1.5M ECU?

[dlaing]

What dreaded lean midrange condition?

If there is one, just re-mapping will cure it.

I don't really understand the accellerator pump or rather why it is beneficial if a map is rich enough.

[Guest ratchethack]

Dave, Todd Eagan pointed out a while back that the accel pump had been developed at Dynojet for water-cooled racing engines that were intentionally mapped lean, for the purpose of combatting an over-lean condition when throttles are whacked open suddenly. The unanswered question here seems to be why this has any application to FI engines.

 

As I presume many here understand, carbureted engines depend on the volume and velocity of air through the venturis to draw the right amount of fuel through the main jets. When the throttles are snapped open suddenly, there's a lag time until the rev's come up to create higher air flow and pull more fuel through the mains to match. This creates a brief over-lean condition that "real" accelerator pumps in carburetors solve by squirting an extra shot of raw, unmetered fuel into the carb throats as the throttles are opened quickly. When set up properly, it smooths out what would otherwise be a hesitation or stumble under hard acceleration.

 

Theoretically, as you pointed out, the above conditions shouldn't exist with FI motors, as the correct map should be rich enough at all times, working in "real-time" thru the TPS and ECU (no lag time). But according to Todd, there seems to have been significant benefit in some V11's in terms of taming ping with the accel pump feature. I haven't tried it, but if you're game, Todd recommended a 20/20/90 starter setting (20% fuel add/20 rotations/90% throttle). To my way of thinking there shouldn't be much of a down-side (fuel consumption increase should be next to nil), but since it dosen't seem to have "caught on" by now, I have to wonder if it actually does much of anything.

 

Quasi, if you've got a halfway decent match to an "off the shelf" map or especially if you've got a good custom map, as Dave noted, you shouldn't have anything like a lean midrange. If you think you do, I wouldn't use the accel pump feature as a band-aid over the real problem. But that's just me - and as always, YMMV.

[Baldini]

If you haven't already, get PC111/FI set up on a dyno.

 

Some reckon stucchi xover sorts midrange - I did both same time so I don't know.

 

KB

[Guest MikeC]

Hey All,

 

I have the USB PC with the Accel Pump feature on my 2000 V11. My bike would ping when I rolled the throttle open quickly at highway speeds in sixth gear.

I have been making slight adjustments to the accel pump to help with the pinging and I seem to have found what I was looking for. 75% throttle 40/40. It does work.

 

Regarding the stucci or any other X-Over. It's supposed to take out the dip in the 4k to 5K range. I'm not convinced it's worth the money and opted to spend my money elsewhere, like a FBF Filter Kit and USB PC the bike already had Mistral cans when I bought it. I'm currently working on sorting out the surging between 4K and 5K which I'm told is common to the 2000 V11 using the PC. Bad job on MG's part developing a proper ECU Map from what I'm told. So far i'm making good (slight) changes to the map.

 

Mike

[quazi-moto]

I've got the FBF intake along with Stucchi X-over and a pair of Staintunes on my'02 LeMans. I had a dealer load a custom map in my PCIII and they even manipulated the map to try and fatten up the midrange. I still get a little bit of surging between 3500-4000 RPM. The PF4C TPS sensor seems to have helped a little bit and the bike feels stronger at low revs. Balancing the TB's with the Twinmax also tamed some of the vibes, but the bike still has a tendency to cough between 3500-4000 RPM. This is what I meant by the "dreaded lean midrange" condition which several V11 owners have spoken about. Many have reported similar symptoms right in the RPM range that I mentioned. I plan on going to a tuning center with a dyno to get the map dialed in. I was just curious if the accelerator pump utility is worth toying around with. Some people say that they like the abrupt throttle response that the accelerator pump can provide. As far as using it as a band aid to improve a lousy map, I don't think that would be the way to go since it wouldn't really do much, if anything, at steady cruising speeds. I just thought it might be fun to toy with once I get my map sorted on the dyno.

[Guest MikeC]

I've got the FBF intake along with Stucchi X-over and a pair of Staintunes on my'02 LeMans. I had a dealer load a custom map in my PCIII and they even manipulated the map to try and fatten up the midrange. I still get a little bit of surging between 3500-4000 RPM. The PF4C TPS sensor seems to have helped a little bit and the bike feels stronger at low revs. Balancing the TB's with the Twinmax also tamed some of the vibes, but the bike still has a tendency to cough between 3500-4000 RPM. This is what I meant by the "dreaded lean midrange" condition which several V11 owners have spoken about. Many have reported similar symptoms right in the RPM range that I mentioned. I plan on going to a tuning center with a dyno to get the map dialed in. I was just curious if the accelerator pump utility is worth toying around with. Some people say that they like the abrupt throttle response that the accelerator pump can provide. As far as using it as a band aid to improve a lousy map, I don't think that would be the way to go since it wouldn't really do much, if anything, at steady cruising speeds. I just thought it might be fun to toy with once I get my map sorted on the dyno.

57933[/snapback]

 

Quazi...It's not a toy, it is a tool with a purpose and with our Guzzi's it helps with pinging. It won't help with the surging, fine tuning the map will. You can do that yourself if you want. The X-Over won't help with the surging either.

 

Mike

[Skeeve]

I've got the FBF intake along with Stucchi X-over and a pair of Staintunes on my'02 LeMans...

57933[/snapback]

 

'02, so no front balance pipe, right? I know a lot of people say they don't care for the looks of the front balance pipe, & it brings some exhaust sealing issues along w/ it, but it does serve a purpose! Seem like nobody with an '03 forward experiences the "hole" in the mid-range to the extent of the earlier models sans balance tube.

 

I'm not suggesting you retrofit '03 headers to your '02, but... que sera sera?

 

[quazi-moto]

Mike,

Let me clarify my post. I'm not dismissing the accelerator pump as a toy or gimmick, but I figured that if I heard some favorable reviews about it, that I might give it a whirl once I get my map sorted on the dyno. I couldn't really expect it to "fix" my midrange hiccups since its not designed to make a lousy map into a good one.

[al_roethlisberger]

Anyone try the accelerator pump utility in their PCIII? Can it be tweaked to tame the dreaded lean midrange condition that seems to be inherent in the 1.5M ECU?

57848[/snapback]

 

 

"Search" is your friend

 

 

Check out this thread that covers the recommended settings, and quite a bit of info from our "Guzzi PCIII Guru" Todd Eagan:

 

http://www.v11lemans.com/forums/index.php?...&hl=accelerator

 

al