Lifan Xpect EFI Stalling - Page 2

Chris_Top_Her · 08-28-2021, 03:36 AM

Quote:

Originally Posted by mototech77

I also did more research on the ECU diagnostic port. Looks like there are not missing wires like I thought. It appears now that there is power, ground and K-line data. I ordered a Honda 6-pin to OBD2 adapter cable. When it arrives, I’m going to verify the pin-out, then attempt to interface with my ELM adapter. Worth a try at least.

All you need is this https://www.aliexpress.com/item/Diag...27424c4d4kuVOq (als available on ebay) and a genuine or knock off tactrix open port adapter. ECu hud hacker is free to interface with the ECU.

Also I would reset fuel trims (d/c ECU for a bit) since you've made mechanical adjustments to the engine.

7RC · 08-29-2021, 11:13 PM

Did you ever adjust the valves?

SuperNoob · 08-30-2021, 12:54 AM

Quote:

Originally Posted by mototech77

My Lifan Xpect EFI tends to stall when cold,and occasionally when taking off from a light. This is happening just as I start to roll the throttle, before the clutch is engaged

I've noticed the same things with my 2021 X-Pect. It will be idling like a top, then suddenly just stall out like I hit the kill switch or something no warning at all.

Other times it's idling fine and I'll grab a bit of throttle in preparation for takeoff, but it will instantly stall out instead of revving up.

mototech77 · 09-21-2021, 09:03 PM

Quote:

Originally Posted by Chris_Top_Her

All you need is this https://www.aliexpress.com/item/Diag...27424c4d4kuVOq (als available on ebay) and a genuine or knock off tactrix open port adapter. ECu hud hacker is free to interface with the ECU.

Also I would reset fuel trims (d/c ECU for a bit) since you've made mechanical adjustments to the engine.

Thanks. That is not the right adapter, but I was able to locate a Honda compatible 6-pin OBD2 adapter that fits. It works with my ELM327 WiFi reader, connected to the Car Scanner iPhone app. I verified that the TPS was zeroed and I did find one error code related to ECU input voltage. I checked the voltage and found only a .10v difference, so I checked/reseated connections and cleared the code. Code never came back. I went ahead and adjusted the idle speed up some as others have recommended, which seems like it may have done the trick. The throttle body looks like it was machined for an optional IAC valve, but Qipai left it out of the design. I think this might help explain why these are finicky when cold. I say this because it seems to idle cold better if I adjust air bypass valve down when cold, but adjust it back out when warmed up.

mototech77 · 09-21-2021, 09:05 PM

Quote:

Originally Posted by 7RC

Did you ever adjust the valves?

Yes, and I will probably recheck again before long based on other users’ experiences. This is a must on these bikes out of the box. Not the best manufacturing quality control

mototech77 · 09-21-2021, 09:06 PM

Quote:

Originally Posted by SuperNoob

I've noticed the same things with my 2021 X-Pect. It will be idling like a top, then suddenly just stall out like I hit the kill switch or something no warning at all.

Other times it's idling fine and I'll grab a bit of throttle in preparation for takeoff, but it will instantly stall out instead of revving up.

That’s exactly what mine does. Wasn’t what I expected with EFI, but the idle adjustment seems sufficient so far (fingers crossed).

mototech77 · 09-25-2021, 06:32 PM

As of the last ride, since adjusting the air bypass valve to increase idle speed, I did not have any more stalling issues at warmup or thereafter (fingers crossed). The idle is a little higher than I’d like it to be (about 1900), but it beats all the stalling.

Boatguy · 09-25-2021, 07:37 PM

Quote:

Originally Posted by mototech77

As of the last ride, since adjusting the air bypass valve to increase idle speed, I did not have any more stalling issues at warmup or thereafter (fingers crossed). The idle is a little higher than I’d like it to be (about 1900), but it beats all the stalling.

Can you tell us where that bypass valve is?

mototech77 · 09-28-2021, 10:55 PM

Quote:

Originally Posted by Boatguy

Can you tell us where that bypass valve is?

It’s the big flathead screw on the right side of the throttle body. Unlike a carburetor that would adjust the butterfly opening (this screw is on the left side), the air bypass simply allows more or less air to circumvent the throttle plate while leaving the TPS in the same zeroed position. Adjust counterclockwise to increase flow.

Sdmfjon · 10-25-2023, 09:09 PM

I realize this is an old thread but my 2023 x Pect is starting to have the same issue.

The spec plate on the side of the bike says 1500 +/- 100 rpm.
Ithe bike idles steady when warmed up and doesn't skip a beat. When it's cold it is stally.

I had the bike idling at about 1700 RPMs. Never had a stall issue until I adjusted it back down to 1500rpms. At 1500 it stalled once right after start up and once with a throttle crack. Might go back to 1700.

Valves at 0.06mm
Spark plug at 0.65mm
15w40 rotella jaso 2 certified

Has anyone else messed around with it?

rideoutadv · 11-12-2024, 06:42 PM

Another addition to an old thread! I live in the PNW and it's currently Nov and colder than normal, around high 30's. Went for my morning commute today and my normally infallible xpect suddenly died on me. Rode for a couple mins and it died on me again at a traffic light. Noticed it was idling around 1400 RPM and dipping down to the 1100 range every 10 seconds or so. I never touched the little silver idle adjuster/air bypass or whatever it is, and it's always been fine, but I guess this is just too cold for the xpect. I put it in neutral with the bike running, took a flat head screwdriver and adjusted the idle screw up to 1600RPM and the bike seemed a lot more steady, no RPM dipping after the adjustment either. Will report back with further info after a few more weeks of testing is done. I'm thinking that this bike, even despite being EFI, gets slightly less reliable in the cold, but at least it can be mitigated back to 100% reliability.

ProDigit · 11-12-2024, 10:47 PM

Make sure you check the valves on these.
I had to tighten my valves twice within the first 1k miles (they come right from the factory, but loosen during the break-in).

With proper adjusted valves, the xpect should be able to maintain idle down to 1.1k rpm, however, don't set it that low, even if it does idle fine.
Many threads about ruined camshafts due to too low idle (and not enough oil flow)

sburk · 11-13-2024, 10:45 AM

Seen this the other day. You might look into it

Sorry wrong bike

09-25-2021, 06:32 PM	#22
mototech77 Join Date: May 2021 Location: Central Florida Posts: 80	As of the last ride, since adjusting the air bypass valve to increase idle speed, I did not have any more stalling issues at warmup or thereafter (fingers crossed). The idle is a little higher than I’d like it to be (about 1900), but it beats all the stalling. __________________ 2021 Lifan Xpect EFI 2012 DF250rtc 1982 Yamaha Virago XV750 1982 Honda Twinstar CM200
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11-12-2024, 06:42 PM	#26
rideoutadv Join Date: Sep 2024 Location: Washington, USA Posts: 29	Another addition to an old thread! I live in the PNW and it's currently Nov and colder than normal, around high 30's. Went for my morning commute today and my normally infallible xpect suddenly died on me. Rode for a couple mins and it died on me again at a traffic light. Noticed it was idling around 1400 RPM and dipping down to the 1100 range every 10 seconds or so. I never touched the little silver idle adjuster/air bypass or whatever it is, and it's always been fine, but I guess this is just too cold for the xpect. I put it in neutral with the bike running, took a flat head screwdriver and adjusted the idle screw up to 1600RPM and the bike seemed a lot more steady, no RPM dipping after the adjustment either. Will report back with further info after a few more weeks of testing is done. I'm thinking that this bike, even despite being EFI, gets slightly less reliable in the cold, but at least it can be mitigated back to 100% reliability. __________________ Current Bike: 2020 Lifan Xpect w/ JT 17 Tooth Front Sprocket Past Bikes: 2022 Honda Navi - Stolen 2016 Honda CB500x - T boned by idiot, totaled ? Honda CRF100F - 'Stolen' by grandpa ? Honda CRF70 - Sold to friends Honda/Suzuki 50cc Kids Bikes - Sold to friends Last edited by rideoutadv; 11-12-2024 at 09:41 PM.
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11-12-2024, 10:47 PM	#27
ProDigit Join Date: Aug 2013 Location: FL Posts: 380	Make sure you check the valves on these. I had to tighten my valves twice within the first 1k miles (they come right from the factory, but loosen during the break-in). With proper adjusted valves, the xpect should be able to maintain idle down to 1.1k rpm, however, don't set it that low, even if it does idle fine. Many threads about ruined camshafts due to too low idle (and not enough oil flow) __________________
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11-13-2024, 10:45 AM	#28
sburk Join Date: Oct 2023 Location: north east missouri Posts: 41	Seen this the other day. You might look into it Sorry wrong bike Last edited by sburk; 11-13-2024 at 11:10 AM. Reason: Wrong bike
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08-29-2021, 11:13 PM	#17
7RC Join Date: Oct 2020 Posts: 5	Did you ever adjust the valves?
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10-25-2023, 09:09 PM	#25
Sdmfjon Join Date: Oct 2023 Posts: 46	I realize this is an old thread but my 2023 x Pect is starting to have the same issue. The spec plate on the side of the bike says 1500 +/- 100 rpm. Ithe bike idles steady when warmed up and doesn't skip a beat. When it's cold it is stally. I had the bike idling at about 1700 RPMs. Never had a stall issue until I adjusted it back down to 1500rpms. At 1500 it stalled once right after start up and once with a throttle crack. Might go back to 1700. Valves at 0.06mm Spark plug at 0.65mm 15w40 rotella jaso 2 certified Has anyone else messed around with it?
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