PCIIIusb "Accelerator Pump" Function

[al_roethlisberger]

Since I've seen it come up a couple times in the last month in other threads, I just thought I'd ask if anyone has really looked into it's function, and possibly given it a try?

 

http://www.powercommander.com/accelpump.shtml

 

 

From the few comments people have made about it's possibly combating "pinging" under hard acceleration, it might be an interesting experiment for someone with a PCIII and the detonation problem.

 

Maybe Todd Eagan will see this post, and can comment as well?

 

 

My bike is actually running pretty well in this respect, so if only really addresses the pinging issue, it's probably not something I need. But I am still curious how it works, and how well.

 

al

[Guest dkgross]

I'll be anxious to hear what Todd says as well. I'll be ordering my PCIII and FBF kit next paycheck My bike has ALWAYS pinged under hard acceleration, even after a fresh valve adjust/tb sync. Drives me nuts...

[Guest Bruce]

dk

Try bumping up that TPS setting a little, it made a huge difference on my bike. I am currently at .65 V.

 

My bike still had the yellow paint on all the adjustments so I am fairly sure the dealer never touched it. Also, the TPS adjustment is a little fiddly so the factory probably just gets it close. Mine was at .45 V originally and I've heard of others that are lower still ( spec is .5 V at idle ). I also was going to buy the same parts as you for the same reason.

 

Here's a guess as to what happens. As the bike breaks in the idle goes up so you back off on the idle speed screw. This in turn reduces the throttle opening which would then have a lower reading at the TPS.

 

Here's a guess as to how it works. The computer compares readings from the TPS and the cam. If these 'match up' it assumes you are traveling at a steady pace and keeps the amount of fuel supplied steady. If you then open the throttle it sees that the throttle is ahead of the cam and knows you want to accelerate. So it delivers more fuel. If you close the throttle it sees that the cam is ahead of the throttle and knows you want to decelerate and cuts fuel accordingly.

 

Therefore that reference point for the TBS is critical to getting the right amount of fuel for what you are trying to do. If it is a little low then the computer will under estimate the amount of fuel needed and it will run lean. Rattle, rattle, rattle.

 

This may be something you have to do yourself because a) the dealer doesn't know what in the hell you're talking about or he can not by law fiddle with these things. It is very easy. Do a thorough tune up first.

 

Seat of the pants feel is that there is still more to be gained so the parts remain on my wish list, but I no longer feel that it is essential. The ridability is now quite good.

[Guest dkgross]

thanks for the great explanation, bruce. I'm a tad inept with the mechanical stuff, but I'll see if I can hook up with one of my local Guzisti that knows how and has the tools to do this right.

 

I do trust the guys at Moto I a hell of a lot, so I may just swing by there and ask Micha or Jason to give it a check...

 

grazie!

[Guest Brian Robson]

I agree with Bruce. I have my TPS set to the same value and the bike runs smoothly with no pinging at all.

[gthyni]

Adjusting the TPS to fatten the mixture does work and is a free fix,

but it has it's limitations if you have made mods on intake/exhaust.

• it does not work at full throttle
  
• it fattens up over the whole register if needed or not loosing power in some spots.
  
• the accelator pumps adds fuel at a point of need not all the time
  

Fatter mix = colder engine, less power

Leaner mix = hotter engine, more power

The trick is to get maximum power without overheating.

 

Pinging is caused combination of heat and load,

by added a little fuel (or water) at hard acceleration

things are cooled down a bit.

 

Of course higher octane petrol also reduce pinging.

[Guest Bruce]

I agree completely with gthyni. Increasing the TPS setting would not be as effective as a better map and maybe better plumbing. None the less I suspected that my bike was set very lean and this decreased performance and also pinging can be a very bad thing ( having holed a piston or two ).

 

My bike went from significant pinging and so-so ridability to no pinging and excellent throttle response. It probably didn't increase maximum horsepower at all but the mid range is much much better ( I know, I know the old seat dyno is easily fooled ). The next step is to see if the fuel milage has dropped significantly. It should be using more fuel but the question is it more effective or simply polluting the air. Hopefully I'll get a good read next weekend.

 

Also, Europe may have higher octane fuel available and engine settings may also be different.

[RacerX]

http://www.powercommander.com/accelpump.shtml

 

From the few comments people have made about it's possibly combating "pinging" under hard acceleration, it might be an interesting experiment for someone with a PCIII and the detonation problem.

 

Maybe Todd Eagan will see this post, and can comment as well?

Al/All,

 

I have tinkered a bit with the Accel pump feature, and found it to be fairly noticable on our bikes. While I haven't had much time tinkering with it on the V11S motor in my bike, I can tell you about how it felt on the Cal motor.

If you keep the fuel add at 20% or less, for under 20 rotations, it is pretty evident in "seat of the pants" acceleration tests. I plan on doing extensive testing once my motorwork is finalized on the V11S motor. Since my 'S' motor doesn't ping, I suppose I can't accurately say if it would combat pinging, but I suspect in theory it just might. No complaining about low fuel mileage though guys.

I'd be interested in helping any Guzzisti out that is within driving distance to Central CA that has pinging problems. Feel free to mail me direct.

 

Bruce, good stab, but our F.I. systems aren't quite that elaborate... idle voltage does infact affect running TPS voltage, so it is best to check your TPS voltage by a simple, key on/motor off. I'm not sure of your voltage translations, but idle voltage is still 150mV (linkage disconneted to set idle), and @350mV (linkage connected - OEM settings).

 

I have found most of the bikes to run best in the 475-525mV range, and infact that is the value that most of the PCIII maps are built around except on the all "stock-bike" maps. Anyone who has tried setting it, knows that anywhere in this range should be acceptable, as it is hard as hell to nail anything precise. If you're within 10mV or so, consider it done.

 

My $.02,

Todd@GuzziTech.com

Certified PCIII Tech

[al_roethlisberger]

So, from the brief instructions I've reviewed, there are three parameters to set for the Accel Pump feature:

 

1) Amount of fuel

2) Number of engine revolutions to add fuel

3) Sensitivity of throttle position movement to add fuel

 

 

It sounds like you gave us 1 & 2:

 

 

If you keep the fuel add at 20% or less, for under 20 rotations, it is pretty evident in "seat of the pants" acceleration tests.

 

 

But what do you recommend for paramter #3 based on your tinkering?

 

With that last bit of info, for those of us interested, it would give us a good place to start

 

 

 

Thanks for the feedback Todd

 

 

al

[Mike Stewart]

Al,

 

I think you should just download the accelerator pump program from Powercommander and then dial it in as per Todd, just play with the sensitivity level to see what suits your needs. I would start off in the lowest sensitivity and then raise it up little by little untill you do not notice a difference and then back it off some. Everyones riding style is different so what might be good for Todd may not be good for me.

 

Just a thought,

Mike

[Guest Brian Robson]

Thanks to the sale of my Trident, I bought a PC111usb...yowza what an improvement in drivability and throttle response.

I decided to download the Accelerator Pump and set it at 90% throttle, 20% fuel and 20 revolutions.

I'll be riding tomorrow and will let you know how it feels

[al_roethlisberger]

Great advice Mike.... and is what I was thinking

 

But I was just trolling for a good known "base" to start from

 

 

 

Brian, definitely keep us in the loop, as I'll be very interested to hear your results... including mileage "impact"

 

 

al

[Guest Brian Robson]

Al, I set it up last night and went for a ride this am. I won't have any fuel figures until the tank is filled and emptied but there was a noticeable change.

I repeated a favourite loop of road several times and tried the corner in 3rd, 4th and 5th gears.

The best description is that the fueling now feels like a perfectly set up accelerator pump equipped carburetor.

There is quick response at the settings and while with the power of the Guzzi there is little danger of highsiding, with the 90/20/20 settings there is no abruptness and cornering can be smoother and faster, as I'm not gearing down as well as braking prior to the corner.

I'm not lugging the bike through the corners, instead of 5500rpm, I'm now around 4800 rpm, with the same feeling when I open the throttle. I think this is what I'm looking for with the pump feature and I will keep it at these settings. They seem to middle of the road as per Dynojet and Todd's thoughts and I am delighted.

[Motomonster]

Why is this USB only?

[Guest ratchethack]

Brian, this sounds impressive & exactly what I'm looking for lately myself. Which PCIII map are you running? Also potentially important - what mods have you done, intake & exhaust in particular? I'm within a quick ride of Todd & want to see if I can combine the benefit of his generosity (per his post above) & expertise with your findings & give it a go:thumbsup: