| Author |
Message |
    
Jsimpkins
| | Posted on Thursday, August 30, 2007 - 07:02 pm: | 
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To all with the Surging problem. I've been fighting this with my 02' X1 since I purchased it. I tried everything, and the dealer was useless. So as a last ditch I did the following...and it WORKED! Pass it on!
I pretty much figured that the mixture was too lean between
1000 and 3500 RPM. So the issue was how to en-richen the mixture. I had
done a number of TPS resets as suggested and that did not clear the
problem up at all. So I decided to try and en-richen the
mixture by faking the ECU out. I did the normal TPS reset, pushing the
throttle forward until is slightly sticks. Then I zeroed it there. Next
I used the idle adjuster to slightly open the throttle while watching
the VDST until the throttle read .20 degree. I then zeroed the TPS at
this point. This causes the ECU to think the throttle is slightly more
open than it really is and this in turn en-richens the mixture just a
tad. The bike runs great now; I've experienced no stumbling, coughing
or surging since doing this. It also seems (seat of the pants) to make
more power as well. Its much easier to lift the front tire and carry it
than before.
Just an FYI, not sure if you know about this trick. |
Sparky
| | Posted on Thursday, August 30, 2007 - 08:18 pm: |
|
Can you explain a normal reset a little more clearly? You said,
quote:I did the normal TPS reset, pushing the
throttle forward until is slightly sticks. Then I zeroed it there.
Did you leave something out, the part about backing out the idle speed screw or was that understood?
I think your logic is flawed though. Here's why. When the TPS is zeroed at a throttle opening that is not completely closed, in your case at 0.20 degrees, there is going to be a certain amount of air passing through the throttle but the ECM is only supplying enough fuel for a completely closed throttle. If anything, your final idle mixture should be slightly leaner than if you didn't do the second TPS reset. Does this make sense or am I missing something?
Perhaps there is something else going on with your bike that is making it seem to work so well. Maybe the O2 sensor is sensing a lean mix and the ECM is compensating by richening the mixture? I don't know, but you seem to be having interesting results. If someone else can validate your procedure and verify the same results, you deserve a gold star! |
Al_lighton
| | Posted on Friday, August 31, 2007 - 01:53 am: |
|
As indicated in the other thread where you discussed this, what you did normally has the opposite effect of causing low throttle angle driveability issues...rough running, intake coughs, etc.
But hey, if it's working, who's to argue with success. |
Jsimpkins
| | Posted on Sunday, September 02, 2007 - 01:04 pm: |
|
Although the above did help I still had an issue with a skip or miss in open loop mode. I started checking the VDST again and just happen to catch the engine temp read 47F, then to 60F then to 275F then back to 32F etc.. This was after the bike had just been ridden. I also noticed that when the temp was freaking out, it ran like crap, either too rich or missed in over heat skip spark mode. Investigating further I found that the ET wire was very tight and rubbing against the cylinder head. I could jiggle it and replicate the problem. It all finally started making sense. When the bike warmed the ET sensor would start freaking out and causing a rich to lean run and sometimes a flat out over-temp condition which caused the ECU to go into skip spark mode (the ECU is programmed to shut the bike down if the engine temp reaches 500F). This was the "miss" I would experience randomly. The surging was the ECU switching from "enrichen mode" (cold start up mode) to normal temp mode.
I replaced the ET sensor and the O2 sensor(for good measure) (also I did another standard TPS reset) and the bikes never run better. Heh? I bet the thing was bad from the factory, of course the Harley dealer never had a clue.
When purchasing the above parts and a tire at the dealer, I spoke to a mechanic/tech; turns out he used to work at the Buell factory as a mechanic. I told him about my issues and he said, "when ever he works on a drive-ability problem the first thing he does is check/replace the ET sensor and O2 sensor". He said there was a rash of ET sensor problems with the early EFI Buells; and this caused the classic "surging" problem many experienced. Hopefully my fuel mileage will increase with the new sensors as well.
Hopefully this will help others that are experiencing these problems.
Jason |
Sparky
| | Posted on Monday, September 03, 2007 - 01:39 am: |
|
Wouldn't it be wonderful if we could download a snapshot of telemetry of our bikes sensors for a specified time period? That kind of information technology would greatly simplify resolving problems like the kind Jason had. Race bikes have this, why not street bikes? |
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X1 Surging problem Solved