UK Buell Enthusiasts Group

Intake leak test - help
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Author:  tazwolf [ Tue Jul 04, 2017 4:38 pm ]
Post subject:  Intake leak test - help

would anybody be willing to help me interpret some logs?
I changed the intake seals and exhaust seals on my stock 2006 buell Uly.
i am getting a high EGO Correction at idle at around 120 and I have a high AFv at 105-109-115
so I thought I would test if I had botched the job, before I was getting hanging rpms when the revs fell back to idle but that has gone.
The service manual recommends doing the propane test when the bike is hot and idling.
Sooo, I put on a pair of very dark trousers, take off the scoops, fire extinguisher in backpack and drive off to a remote car park and spray propane around the intake seal area on both left and right hand side.
No discernible rise in rpm so I go home relieved that nothing blew up or caught fire.
Checking the logs in Megalogviewer (logged in ECMDroid) I can see that the the EGO correction drops from by around 15-20 and the o2 sensor output goes wobbly.
What does it mean?

Author:  pash [ Tue Jul 04, 2017 7:39 pm ]
Post subject:  Re: Intake leak test - help

I'll have to look at one of my logs, but the O2 sensor should bounce around as the ECM puts fuel in, then takes it out to try and keep a stoichiometric mixture. The O2 sensor only starts to work when it is up to temperature.

You need to bear in mind that when you are letting propane escape it will eventually get sucked in though the intake. The intake seal response should be instantaneous though if they are leaking.

At which point did you start letting the propane out?

You are actually fighting the ECM by offering more fuel as as you have seen, the ECM reduces the EGO correction. On an X1, the closed loop correction at idle is turned off. You could try this on your XB and see if the revs go up (but bear in mind my point about the propane finding its way in anyway).

As an aside, I would have thought WD40 was better to try as that will sit as a liquid until it gets drawn through the seals.

Author:  tazwolf [ Tue Jul 04, 2017 8:56 pm ]
Post subject:  Re: Intake leak test - help

Bike was already Hot switiched off the bike and straight on, I connected up ECMDroid and then propaned - in order: twice on the left side of the bike and then twice on the right side. From Start of engine to the end of the log is 2 minutes, roughly 30 second wait.
If the propane did get into the intake would it effect the rpm as well? Its also confusing me that the rpms are (more or less) stable.
Could it be injector o-rings leaking?

I will try again with wd40 - feels a lot safer!
Thanks for your help Pash.


Author:  pash [ Tue Jul 04, 2017 9:38 pm ]
Post subject:  Re: Intake leak test - help

Like I said, you are fighting the ECM, it will never run lean as it is in closed loop, so the revs wont pick up unless you turn the closed loop at idle off in the configuration byte (sorry, I've never used ECMDroid so have no clue how to do it).

It could be the injector seals leaking, but I've not heard that they are a weakness like the intake seals.

So, if it were me, I would:

1. Turn off idle closed loop
2. Increase the tickover until it idles at 1050
3. Use WD40 or carb cleaner locally

BUT... I have never had the sensation that my intake seals were leaking and hence have not looked for the issue. :maz: or kevmean spring to mind as those that have tested for this in the past.

Author:  kevmean [ Wed Jul 05, 2017 3:20 pm ]
Post subject:  Re: Intake leak test - help

If the intake seals are leaking you will instantly hear the change in engine sound as you spray the wd40 on the intake seal area , the same would happen if you spray the injectors ;)
One issue i had with the X1 years ago I am convinced was caused by the exhaust headers being loose, at the time the rest of the exhaust was totally insulated from the chassis by rubber mounts (scorpion can).
After nipping up the headers it ran perfect , my theory was that although you couldn't detect any leak at the headers it was not earthing the exhaust system so was affecting the o2 sensors circuit.
Fuel pressure might be worth checking?
I also had an issue with a dribbly injector which meant if you stopped the engine while hot and then tried to restart it a couple of minutes later it had flooded the engine, leave it stopped long enough and it started again Ok, this was easily cured by using injector cleaner in the fuel, one tank full later and the problem had gone for good.

Author:  tazwolf [ Thu Jul 06, 2017 9:11 pm ]
Post subject:  Re: Intake leak test - help

Ok, so I turned off closed loop idle ecmdroid.
Took off the scoops (stripping a bushing for the right side scoop....ffffffffffff).
took a ride to get the bike warm and sprayed with wd40.
No change in idle. So I am pretty sure I don't have an intake leak and did a proper job of installing
the james intake seals...did something right!! but it goves no solution to my problem.

see second attatched pic. the rpm blips are where I blipped the throttle to mark just before I sprayed.

I then mounted the scoops back on - (except for the bolt with the stripped bushing - zip tied).
Turned closed loop idle back on and rode home form the car park.
You can see how the EGO just gets getting progressively higher and higher each time at idle, as well as the AFV being high the idle ego rises above it. the only thing I can see that correlates is the intake temp but then if I don't have an intake then......stumped...... see first attachment.

Is the bike ok to ride with egos up around 130?

Kevmean - I will check the manifold bolts for tightness, I did change the exhaust seals.

Author:  tazwolf [ Thu Jul 06, 2017 9:17 pm ]
Post subject:  Re: Intake leak test - help

Forgot to mention, I don't think I have a dribbly injector - I sent them off for service but they were fine. Bike starts fine hot or cold. The only issue I have is a high AFV at 109-115 and the even higher EGO /GEGO at idle.
I have not checked fuel pressure as I thought problems with that would show up at higher rpms when the pump has to work harder no?

Author:  Adam [ Fri Jul 07, 2017 3:19 pm ]
Post subject:  Re: Intake leak test - help

I had this mither with my X1 until recently. I cross refd. a Lambda sensor from Halfords, changed intake seals and ex gaskets etc, etc and still had AFV values around 115. I then fitted a cyl head temp sensor from my other X1 brought the AFV back to around 105. I hasten to add, I'm a complete imbecile with FI, unlike carbs which I love working on, so this may just be coincidence. I don't have the facility to check my fuel pressure, but Maz took a look and said it wasn't particularly good.

Author:  tazwolf [ Fri Jul 07, 2017 6:25 pm ]
Post subject:  Re: Intake leak test - help

Did you notice any difference in the performance of the old and new temp sensor,as far as measured temp? I have already have a spare fuel pump so i am thinking of just pulling the old and changing it as i dont have any easy way of measuring the pressure. On the other hand the logs seem to show the ego rising with temp at Engines and i find it difficult with so many unknown variables.

Author:  tazwolf [ Tue Aug 22, 2017 11:36 pm ]
Post subject:  Re: Intake leak test - help

So, an update, I changed the fuel pump. Made a slight difference in the afv as well as being a hell of a lot quieter but I can more or less say that it was not the problem either. The the idle area was still way too lean so i looked at the logs to see how lean it was and multiplied that percentage to the fuel maps in the idle area.
Short term and dirty fix but now i have a afv between 105 and 109, so will leave at that for the moment and just enjoy riding. Ego correction varies between 90 and 120 at the extremes.

Maybe i will change the temp sensor during the winter hibernation but it seems fine from the logs.

Im sure everybody else knows this but when upgrading the fuel pump and using the fuel performnce kit, dont forget to heat up the convoluted fuel line ends with a heat gun between the pump and regulator, do not try to force the fuel line cold onto the regulator barbs like i did otherwise you will damage the fuel line and then have to wait 2 weeks for a new 5 quid fuel line Because they are only available in fuel pump replacement kits in Sweden and not individually.... fustrating ? Not at all.

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