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2008 DL650 - Idles fine, dies on revs > Help please!

8K views 24 replies 7 participants last post by  Mikeys 
#1 · (Edited)
[Solved] 2008 DL650 - Idles fine, dies on revs > Help please!

The bike has just over 60k miles. I bought it about 5k miles ago. It's ran great since then, has had recent valve check and spark plug change.

Problem:

  • Last time I parked it, a couple weeks ago after a long ride, it was fine. A couple days later, I noticed fuel leaking from the exhaust joint under the engine (near the oil filter). Gas had gotten into the front cylinder and hydrolocked it.
  • I pulled the plug and turned it over a few times to get the gas out. I suspect the front fuel injector had failed, or clogged open.
  • I took the front fuel injector off, looked at it, jiggled it, and put it back in. Then I cleaned the air filter and put the bike back together.
  • Now it will start, but takes longer than usual, it runs under idle, but will die with >10% throttle. is a video of it idling and then dying.


Is this consistent with a failed fuel injector, or is there something else going on?

Should I just get a throttle body off ebay and call it a day?

Thank you!


Edit:
Solved! See comment 22.
 
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#2 ·
You say that you have pulled the plug on the front cylinder... did you pull both plugs on that cylinder or only one of the plugs? Were the spark plugs wet after the engine died?
Have you done a fuel flow test? See https://www.stromtrooper.com/dl650-...-about-quick-fuel-pump-flow-test-results.html or https://www.vstrom.info/Smf/index.php/topic,11603.0.html
Similar idle complaints reported, https://www.stromtrooper.com/dl650-...07-starting-running-trouble-de-bug-ideas.html and https://www.stromtrooper.com/dl650-dl650a-2004-2011/320874-engine-stops-while-riding.html
Sorry, it's going to be a process of elimination.
 
#3 ·
Thanks for the info Gert!

I haven't done a fuel flow test.

I pulled the side plug on the front cylinder, it was wet. Should I have let it dry before putting it back in?

I left the other plug in, since I figured one hole would be enough to get the gas out. Is there any reason to pull both?
 
#4 ·
Yes, always dry the plug, for better spark and helps diagnosing later. The 2nd plug could have been overlooked for a while. Pulling both plugs will give you chance to inspect them, for overall condition.
The fact that the spark plug is wet, means that there is fuel in that cylinder, so it appears as though either there may be no spark on the plugs, or sparking at the wrong time or the valves are not closing / opening correctly.
 
#8 ·
I put in a new (ebay used) front fuel injector. Checked for spark on the front side plug (had spark). It started easier, but still died with a bit of gas. I noticed that if I gave it a lot of gas, it would rev up, but the revs would be very unstable, surging up and down. Took it for a ride around the block, and it felt like at a given throttle, the gas input would swing wildly from 20% to 100%.

I checked and tightened the airbox fittings, still the same surging.

Planning to get a measuring cup the next time I'm at the store and do the fuel flow test. I suspect the airbox side throttle body valves might not be working correctly. Whether the motor is dying, or there's a poor electrical connection, I don't know.
 
#9 · (Edited)
If you fuel flow is reasonable, even if not up to full specification, I would suspect the TPS. They are known to cause low rpm throttle response issues. Normally a partially plugged up fuel pump manifests itself at elevated rpms, like 5k or 6 k because the engine is starved for fuel whereas everything is "normal" alt lower engine load. My bike ran fine but pushing it up a mountain road it would not accelerate past 6k. Fuel flow was about 1/3 of specification.

Please confirm: The bike ran normal after the valve check and plug change? Approximately how many miles since that work was done?
 
#12 ·
Please confirm: The bike ran normal after the valve check and plug change? Approximately how many miles since that work was done?
Valves and plugs were done at about 55k. Bike has 62k now, and was running fine until this started happening the last time I parked it (for about a week).

Got some tests done:
Did the fuel flow test, cycled key 3 times, got 300 mL.

I also took a video of the Secondary Throttle Valve Actuator, which appears to be malfunctioning:
https://youtu.be/C0CnV0rzBGI

Is this an issue with the TPS, or with the motor for the Secondary Throttle Valve Actuator?

Or might this be like Gert suggestd, and the rubber vacuum caps/covers?
 
#10 ·
You don't really need a measuring cup. I made use of a 2 liter soft drink bottle and marked the levels with a sharpie / marker pen, after filling with a known volume of liquid.
Count how many coffee cups / mugs it takes to fill the container and then ask your good lady advice on the liquid volume a single cup holds...
 
#13 ·
Your 300ml per 3 cycles is low. Maybe the fuel filter strainer is a bit blocked. The high pressure filter could also be blocked. There have been some success in reverse pumping the high pressure filter to clear it. Google V-strom high pressure fuel filter clean + you tube
The STVA is under the control of the ECU. There have been reports of stepper motor linkages that may require lube, https://www.stromtrooper.com/dl650-dl650a-2004-2011/89178-stva-help-needed.html
 
#16 ·
It is the CA emissions model. Gas tank is 3/4 full

I mucked around some more today, trying to find any spot of wire that had rubbed through (none found), I WD-40'd the SVTA joints and moved the rod back and forth to work it all in there, trying to clean out the moving bits. This might have smoothed out the motion, but did nothing for the problem.

There is no FI code reported. In dealer mode the -C00 is in the middle at no throttle, and goes to the top at 1/3-1/2 throttle, which seems right.

It's starting to seem more and more like either the SVTA motor is no longer strong enough to hold open the valves, there's something wrong with the ECU, or there's a wiring fault somewhere.

I have a friend coming with a '09 Wee tomorrow, and I'll try his ECU.

I'm hesitant to think it's a wiring issue, because there's no FI error code, and I would suspect one would appear with a wiring fault.
 
#20 ·
That sounds like a very likely culprit ("The issue is being caused by a crack in the vent tube inside the tank. [...] The reason that cylinder filled with fuel is because the purge hose from the evap canister routes returning vapor into the throttle bodies.")

Where can I buy plugs or end caps for the hoses/nozzles? I checked Lowes, but they don't have anything small enough.


Also: I had a friend with an '09 Wee stop by. Turns out, the behavior of the SVTA with the engine off is completely normal, so the issue isn't the SVTA motor or electrical circuit, but almost certainly a vacuum issue, as Mikeys and Gert have been suggesting.
 
#25 ·
The CA emissions are suppose to be "sealed". So by plugging the system off,, the tank "should" be non vented. Possibly creating a vacuum as the fuel is used. If you read the post I attached, bdesj vented his cap but was not sure if it was needed. If you have any questions, I would PM him and see what he thinks or how he vented the cap or maybe just driving it for a while and pop the cap and see if it has created a vacuum.
 
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