Rubbermount_EFI Does Your EFI 1200 Do The Herky Jerk With Throttle Just Barely Cracked?

[FiremanTx]

Mine has the same problem, hoping to get it tuned out with the powervision real soon.

[mr.coffee]

Originally Posted by SNMbass

3 different dealers have said it's "normal" for EFI Sporties.

That's why I love my bike but hate the MoCo. Yep, mine does it too. For them to claim "normal" is ignorant.

Anybody know if IEDs help?

-m

[SNMbass]

Wasn't looking for everybody's advice, just whether your bike does it or not.

Regarding Ied's - tried 'em - didn't help. They only act in the closed loop regions and what I'm describing is not in closed loop.

Regarding running lean - I doubt it. The fuel map in this region is rich, and I made it even richer to no avail. Increased thre VEs next, no smiles from that either. I also tried making it leaner. No help there either.

Data samples show typical MAP load is 9 - 13 kPA with throttle cracked and rpms 1200 - 2200. The target AFR was 13. It can only be taken as low as 12 in the SEPST software. The SEPST software does not show MAP below 20 kPA, so that's the lowest region which can be altered in the fuel map. What the ECU does when actual MAP load is 10 kPA, only H-D engineering folks would know. Maybe it uses the same values that it has for 20 kPA, maybe it has some factory presets. So, in reality, the only way to know for sure is an exhaust gas analyzer. So, theres one area at least where the ECU is less sophisticated than the ECU for Big Twins.

The guy who tuned my bike changed the O2 sensor "bias" from 440 mV to 600 mV. I asked him why. He said the Motor Co. recommends it. Doing that would make the bike run a bit richer than stoichiometric in closed loop, and hence out of EPA compliance. Hard to imagine H-D would openly recommend that. Also, it will make the bike run a little cooler and eat up more gas. It accomplishes exactly the same thing as Ieds.

I have been wondering if I have a flaky throttle position sensor, and repeatedly asked the tech to try to check it out. Never really got an answer. I may just change it myself to see. Only about $35 and not hard to get to.

As for the conditions I'm complaining about being "lugging" and dangerous, I don't buy it. Carbureted bikes I've ridden DON'T jerk around like this. As one other responder said - a little twist on the throttle and the bike accelerates without any strain. I guess I could ride thru my sub in 1st gear at 25 mph just to stay above 2,200 revs. Neighbors would be impressed.

[WildThang]

Back when my sporty had pretty much stock exhaust and intake, it had the stumble also...Nightrider's XIEDs cured that...

[SNMbass]

BTW, if anybody wants to know,

My bolt-ons are SE Street Performance slip-ons and SE high flow air filter.

The performance numbers before / after dyno tuning were:

69 / 73 HP

73 / 77 lb.-ft. torque

They gave me complete printouts of the calibration files before and after. They started with 176FM005 stage 1 download. I had been using 171FM004 stage 1 download, altered many times over trying to "tune out" the quirk.

Aside from the quirky cracked-throttle stumbles, this is a good running bike.

[Lesgeaux]

My 2011 XL120C with about 2000miles just started to notice the same thing at times. I have not been tracking it on paper but it has been getting agravateing, now I kinda happy to know it is not just my bike, you know the why does this just happen to me syndrome.

I did not notice this before 1500 miles although I did notice that 20 miles an hour in first is a balancing act. This is my first Harley.

[Anaxios]

Originally Posted by SNMbass

Wasn't looking for everybody's advice, just whether your bike does it or not...

+1

I learned a lot searching 'surge'.

[2007Low]

Originally Posted by SNMbass

Wasn't looking for everybody's advice, just whether your bike does it or not.

Regarding Ied's - tried 'em - didn't help. They only act in the closed loop regions and what I'm describing is not in closed loop.

Regarding running lean - I doubt it. The fuel map in this region is rich, and I made it even richer to no avail. Increased thre VEs next, no smiles from that either. I also tried making it leaner. No help there either.

Data samples show typical MAP load is 9 - 13 kPA with throttle cracked and rpms 1200 - 2200. The target AFR was 13. It can only be taken as low as 12 in the SEPST software. The SEPST software does not show MAP below 20 kPA, so that's the lowest region which can be altered in the fuel map. What the ECU does when actual MAP load is 10 kPA, only H-D engineering folks would know. Maybe it uses the same values that it has for 20 kPA, maybe it has some factory presets. So, in reality, the only way to know for sure is an exhaust gas analyzer. So, theres one area at least where the ECU is less sophisticated than the ECU for Big Twins.

The guy who tuned my bike changed the O2 sensor "bias" from 440 mV to 600 mV. I asked him why. He said the Motor Co. recommends it. Doing that would make the bike run a bit richer than stoichiometric in closed loop, and hence out of EPA compliance. Hard to imagine H-D would openly recommend that. Also, it will make the bike run a little cooler and eat up more gas. It accomplishes exactly the same thing as Ieds.

I have been wondering if I have a flaky throttle position sensor, and repeatedly asked the tech to try to check it out. Never really got an answer. I may just change it myself to see. Only about $35 and not hard to get to.

As for the conditions I'm complaining about being "lugging" and dangerous, I don't buy it. Carbureted bikes I've ridden DON'T jerk around like this. As one other responder said - a little twist on the throttle and the bike accelerates without any strain. I guess I could ride thru my sub in 1st gear at 25 mph just to stay above 2,200 revs. Neighbors would be impressed.

You might want to mention that next time you post, this is a forum. You get what you get.

[KevinJ]

It could also be a limitation of the efi system. Like it can't figure out what it should do and so it just adds fuel and immediately compensates by removing fuel.

My bike doesn't do it. Or maybe my throttle hand is steadier than yours

[SNMbass]

I think I'll get over it eventually