TnC14
Parking Attendant
Posts: 28
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posted November 15, 2009 02:44 PM
 Edited By: TnC14 on 15 Nov 2009 22:45
3,000rpm Deaccel Pop & acceleration stumble?
Has anyone else noticed a deacceleration pop at 3,000rpm with throttle closed?
After a hard acceleration up through the rpm's, then close the throttle to slow down... or, when coming down off a mountain, as the tach sweeps (down) past the 3,000 point, my bike will backfire through the mufflers, sometimes loud.
My bike has Muzzy's full dual exhaust, BMC race air filter, PC-V power commander with map from Fuel Moto, AutoTune wideband O2 kit for PC-V, FLIES OUT.
When I put these items on the bike, DynoJet said to block off the PAIR hose to prevent popping on deacceleration. Well, the bke still pops, so, I ordered the Muzzys blockoff plates to simply eliminate the PAIR all together. After a day of hand cramping to put them on, the bike still does it..
I also have a remote switch on the AutoTune kit, so I can deactivate the AutoTune from adjusting the installed basemap. The bike still pops at 3k on deacceleration.
So, I thought I'd manually lean out closed throttle around the 3k area. I (think) it helped a little, not eliminating it, but making another issue worse.
The second issue this bike shows is, when in 1st or 2nd gear, riding at steady state say 2k - 3k, whack the throttle open and the bike will lean cough, and not pull "clean" until a coulple of seconds seems to have gone by. What's weird about this, it doesn't exhibit this in the higher gears....I guess where the motor is "loaded" and can't rev fast enough like it tries to do in 1st & 2nd gear. It almost acts like it needs an "accelerator pump" function for 1st and 2nd gears.
I know I need to take the bike to a good, Dyno tuner...I just have to find one I trust near me.
But, until then, I was curious if anybody else had noticed this "pop" at 3k, and, those who have flies out, a stumble when throttle wacked open around the 3k area also???
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'09 Metallic Black Concours14 ABS.
PC-V Power Commander.
Power Commander Auto-Tune Kit.
Muzzy's stepped tube header - Dual carbon oval cans.
Muzzy's lowering links.
BMC-Race air filter.
Flies out.
  
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oncourse
Expert Class
I hate flies!!!
Posts: 467
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posted November 15, 2009 06:34 PM
I think everyone has the pop on decel, even stock, but more pronounced with the setups like we have. I never had a complete backfire bang, just a low boom boom etc. Now you must be running a zx14 header with no cat's, my friends stocker has no cats and will bang real loud sometimes, he has only cats out and 2 bros slip on, so no cats makes it loud, real loud at times.
My experince, with my setup, is that on hot days, and after riding for a while, I will go into a long decel due to a slow turn or a red light, if it is into a slow turn I get a hesitation sometimes going back into light throttle. If it is coming into a stop at a red light, I might go to take off and it stalls way to easy. So, Yes I do have a problem sometimes, but mostly not. Hot humid days seems to make it worse, but if I whack it she does not hesitate. It is just after the long decel and then part throttle in lower gears that this exists.
I assume you fuel moto had no exact map for your application as to why you went with auto tune. Basically they probably took a pc3 map and converted it. to pcv language. Too bad you do not have a fuel air readout as it would probably explain what is going on, remember that the pc3 or 5 relies heavily on tps input and not actual load.....
Rob
____________
True intellegence is not measured by your degrees.
04 klr 250 Lots of mods and 70 MPG!!
08 Connie 2 bros. Carbon. Helibars. Flies out, PC3!!!
2003 kx 500 SOLD
2004 KX 500 In service now, whata BEAST!
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TnC14
Parking Attendant
Posts: 28
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posted November 17, 2009 03:33 PM
quote:
I think everyone has the pop on decel, even stock, but more pronounced with the setups like we have. I never had a complete backfire bang, just a low boom boom etc. Now you must be running a zx14 header with no cat's, my friends stocker has no cats and will bang real loud sometimes, he has only cats out and 2 bros slip on, so no cats makes it loud, real loud at times.
My experince, with my setup, is that on hot days, and after riding for a while, I will go into a long decel due to a slow turn or a red light, if it is into a slow turn I get a hesitation sometimes going back into light throttle. If it is coming into a stop at a red light, I might go to take off and it stalls way to easy. So, Yes I do have a problem sometimes, but mostly not. Hot humid days seems to make it worse, but if I whack it she does not hesitate. It is just after the long decel and then part throttle in lower gears that this exists.
I assume you fuel moto had no exact map for your application as to why you went with auto tune. Basically they probably took a pc3 map and converted it. to pcv language. Too bad you do not have a fuel air readout as it would probably explain what is going on, remember that the pc3 or 5 relies heavily on tps input and not actual load.....
Rob
While I don't have an AF readout, I can view my AutoTune trim tables. It is attempting to pull up to -25 from the fuel map at the closed throttle around the 2750-3500rpm. While this seems to reduce the big boom-pop, it still has small crackle which I could live with. HOWEVER, with these changes, the stumble is severe with these trims.
Does your PC-III have an "accelerator pump" function?
My PC-V shows it in the menus, but, I don't know if it is an activated function for the C-14.
{There are several functions that don't work like gear selected, temperature, etc.}
The pump settings look tricky to input, with throttle delta change, etc.
But, if this feature would work, that might give me the shot of fuel I need to stop the accel stumble, and I could keep my wideband O2's trim to reduce the deaccel pop.
____________
'09 Metallic Black Concours14 ABS.
PC-V Power Commander.
Power Commander Auto-Tune Kit.
Muzzy's stepped tube header - Dual carbon oval cans.
Muzzy's lowering links.
BMC-Race air filter.
Flies out.
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oncourse
Expert Class
I hate flies!!!
Posts: 467
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posted November 19, 2009 03:49 AM
Sounds like it is really trying to push lean on decel and recovery from that would lag a bit, and I know how bad it can backfire out the exhaust with no cat's, BANG!
I do not know If I have that accel. pump function, as for the pc5 the only way to get gear position is it has to be hardwired to the ecu. If you bought the pc5 from fuel moto maybe they can suggest something?
Rob
____________
True intellegence is not measured by your degrees.
04 klr 250 Lots of mods and 70 MPG!!
08 Connie 2 bros. Carbon. Helibars. Flies out, PC3!!!
2003 kx 500 SOLD
2004 KX 500 In service now, whata BEAST!
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FastestBusaAround
Needs a life
I eat Fish...
Posts: 7889
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posted November 27, 2009 02:51 PM
The accel pump won't change that - all it does it let you twist less to get WOT...won't change anything on decel. That's a known issue on the 1400 engine in both the ZX and the C. There are a few solutions for that, but none of the them, except using the neutral map will eliminate that pop completely and the neutral map fix causes the GPS indicator NOT to work...
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FYYFF!!!
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