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2016 Audace Hesitation/Surging under Heavy Acceleration

K

Ken Wantje

Cruisin' Guzzisti
Joined
Jul 26, 2021
Messages
135
Location
Saugerties, NY 12477
I have recently noticed under heavy acceleration I am experiencing what I would describe as surging or hesitation above 3000 rpm. It seems as though either the fuel is being restricted or the air flow. It's not a sudden loss as if the ignition was cutting out. I checked the air cleaner and it's clean. Any ideas on how to proceed with troubleshooting? Thanks!
 
Sounds like your fuel injectors may be dirty. What mileage are you at?
Is your fuel filter an all metal one or the problematic metal/plastic unit?
Have you ever balanced the throttle bodies?
 
Ken Wantje said:
I have recently noticed under heavy acceleration I am experiencing what I would describe as surging or hesitation above 3000 rpm. It seems as though either the fuel is being restricted or the air flow. It's not a sudden loss as if the ignition was cutting out. I checked the air cleaner and it's clean. Any ideas on how to proceed with troubleshooting? Thanks!
Click to expand...
Ken, when was your last real service? Stock fueling or ? If my kit, please email me direct.
 
So the bike has 20k miles. I will have to take a closer look at the fuel filter, it's the original, as to whether it's all metal or plastic. I should probably replace it. Is the fuel filter in the tank and how difficult is it to replace? I did run some sea foam through the fuel last summer before putting it away for the winter but the condition is still there as of last weekend. I have modified the fuel map to run a bit richer and I put at least 12K miles on it before this condition developed.
 
Last edited:
Info on maintenance would help. Ever had it tuned up? Valve lash set? Changed the fuel filter? Cleaned the throttle body? Riding w/open pipes and no fueling? Had any parameters reset?
 
I don't believe this is a balancing issue since the bike does accelerate smoothly most of the time, it's only under full throttle acceleration that I notice the hesitation.
 
Ken Wantje said:
I have modified the fuel map to run a bit richer and I put at least 12K miles on it before this condition developed.
Click to expand...
Via what means? If you're using Diag, this thread will be deleted.
You ignored my questions above also.
 
I was using a Booster Plug to tweak the fuel mixture, but that has been removed to eliminate it from the equation. I have not done a valve adjustment yet, but the spark plugs were replaced according to the suggested schedule. I have always used non-ethanol fuel. Stock exhaust. The more I think about it the more it seems like a fuel filter, which is not even mentioned in the scheduled maintenance or the service manual, at least not where I could find it?
 
GTM® said:
Noted here many times... These do not work, and the transition from closed to open loop on the fuel map is precisely where you are having the issue.
Service is paramount always, and the fuel filter is in tank. ALWAYS try a search; https://www.guzzitech.com/forums/threads/california-1400-fuel-filter.14216/
Click to expand...
As I mentioned, I removed the Booster Plug to determine if this was causing my problem and it was not. From what I have read and understand about how it operates, it should not have any effect on the operation of the Lambda/o2 sensor circuit, it simply skews the air temperature data causing the ECU to think it's colder outside, thus making the AFR richer. With the exception of the valve adjustment, I have serviced my Audace according to the recommended intervals, and oddly enough there is no mention of the fuel filter. Unless I got a bad batch of gas, which is unlikely, I would expect the fuel filter to be good to at least 60k miles. Is it possible there could be an issue with the throttle position sensor if that's what it's called. from what I understand the first generation of drive by wire has a cable from the throttle to a device under the tank that then transmits the throttle position to the throttle body?
 
In the 12Kmi you put on you should have adjusted valves twice. When was last time? What mode is it in when this occurs? Do you have the traction control off?
 
In addition to above, check tire pressures. Otherwise, things like this are nearly impossible to diagnose via the net.
 
I concede to needing to have the valves adjusted but not that this could be causing my problem. I have traction control OFF and I run in VELOCE mode most of the time. The problem only happens if I accelerate at full throttle. If I accelerate a little less aggressively I don't get the surging/hesitation. This leads me to believe it's possibly the device that the throttle cable connects to and then sends the signal to the throttle body to open/close. Perhaps under a full and fast throttle position change there is a mechanical lag. I'll have to see if I can meter the output of this device and see if there is a steady and consistent signal or if it's lagging in any way....
 
You could also have a spark plug or spark plug wire/cap going bad. I've had plug wires work fine at idle, then have issues at other throttle openings where the stresses are higher. With our bikes having dual plugs per cylinder it may help to mask the issue as well.

Dave
 
I did change the plugs at the recommended interval and this does not feel like spark cutting out though I agree with the dual plugs it could mask it somewhat. It's not specific to an RPM range rather how quickly I roll the throttle on...
 
Ken Wantje said:
I have modified the fuel map to run a bit richer and I put at least 12K miles on it before this condition developed.
Click to expand...

Booster Plugs do not modify the fuel map.

I suspect there is more here than you are owning up too.

From what I have read, your fuel injection map is out of alignment with physical running conditions.

I would perform a TPS reset, and then re-evaluate it with a test drive.

This would makes sense with your statements about your observations.
 
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