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Bike Idling at 3k RPM!


Rogue_Biker

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Hi all!  It's been a while since I've actively posted here.  Just been too busy.

 

I have a 2007 VFR800 with 49,500 miles on the clock.  The bike was running fine until very recently.  I attempted my first Starter Valve synchronization, and during this process I followed the factory service manual to the letter, which stated that I should keep the MAP sensor and the vacuum hose connected during the sync process.  However, after I hooked up my sync tool to all four vacuum hoses and started the engine and brought it up to operating temperature, starter valves were all over the place.  See below.

 

37146950881_a757d09174_z.jpg

 

Needless to say it was NOT possible to balance them!  They were too far apart.  I tried.  So I consulted VFRD's archives and I found a video by KaldekBoch who appeared to be very knowledgeable.  In his YouTube video KaldekBoch suggested one should keep the MAP sensor disconnected to get a clean SV Sync.  So I followed his suggestion and I was able to sync my SV and adjust the idle at 1,200 rpm.

 

This was the start of my problem.  When I connected everything up, my bike idled at 2k RPM at first, rising to 3k RPM once the engine is fully warm!  Below is a picture at idle at 150 degree F coolant temp.  It goes higher at 175 degree F!

36774962143_ce5e3c0732_c.jpg

 

Here is the weird thing.  When I disconnect my MAP sensor, the bike's idle returns to sort of normal, around 1,100 RPM.  As soon as I hook up the MAP sensor, boom!  Idle jumps to nearly 3k RPM at full operating temperature!  

 

At first I thought I had a faulty MAP sensor, so I replaced it with a new one.  No change.  Next I replaced the vacuum hoses coming out of the throttle body into the 5-way post, along with the vacuum hose leading to the MAP sensor.  Yet there was no change and the idle remains high.  

 

My next move is to replace the throttle body boots.

 

Anybody have any idea what's going on here?  I'm scratching my head here trying to figure this out.  What else can be wrong except a vacuum leak right?  Because the MAP sensor ONLY gets its data from the throttle body.  Any help would be greatly appreciated.

 

FYI, fuel injectors were recently cleaned and the bike was running very well BEFORE I attempted my starter valve sync.

 

 

 

 

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  • Member Contributer

Hmm, there has to be something that got moved, bumped, disconnected or otherwise not in its normal postion/condition. Hopefully someone with more experience with this than I can chime in soon. It would be great to see you riding the VFR again.

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  • Member Contributer

Don't worry brother ,can adjust balance, VFRD will give you the greatest help, at least, I am from China, have learned a lot of knowledge, we Chinese cyclists, all such problems, are solved, thank god, thank VFRD

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I sure hope I can fix her.  It's been a month now with the bike laid up in the garage....waiting for parts, then me putting in the time to try to figure this out.  I just don't understand how it was running fine before, then once I had her synchronized (with the MAP sensor disconnected), as soon as I connect the MAP the idle revs jump!  2k RPM when cold, nearly 3k RPM when at normal operating temp.  

 

The way I see it the only thing that controls the MAP sensor are the vacuum coming from the Throttle Bodies.  So the path from the engine to the throttle bodies, to the MAP sensor has something to do with it.  It seems the MAP is telling the fuel injectors to pour fuel into the engine at idle (or so it would seem).  New MAP sensor, newly cleaned and balance injectors (which worked perfectly right before this SV Sync).  

 

My throttle body boots arrive tomorrow so replacing the 10-year old ones are my next logical step.  After that....??????  Maybe clean the throttle bodies????  New Starter valves?????  

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  • Member Contributer

If you experience high uncontrolled idle suspect an air leak... on a
fuel injection system *any* air that gets past the throttle bodies the
map just adds the corresponding fuel... the result is high
uncontrollable idle... make sure all the rubber hoses are connected
and in good shape... make sure all the intake boots are tight and in
good flexible shape... if the rubbers are hard and cracked its time
for replacement...

gallery_3131_51_651212.jpg

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Hi Rogue_Biker.

Noticed your picture shows your Fi light to be on! During the Starter Valve synch process your Fi light should display two error codes, one for they MAP Sensor and the other for the IAT Sensor.

Once you've completed the process and everything re-connected you should have NO Fi light indications. Are you sure you have electrically re-connected your IAT and MAP sensors, are all vacuum lines properly connected? Did you disturb any of the linkages from the Wax Pellet unit to the Starter Valves? Does the normal Idle Adjuster work in lowering Idle RPM?

Just tossing up a few ideas.

Good Luck.

Cheers.

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When we did the sync on my 07 at the Spring Ride, the idle came up and would not back down. After a lot of inspection, it was the threaded end of the idle cable at the throttle bodies had frozen. We only thought it was all out. A little WD soak and it backed on down.


Sent from my iPhone using Tapatalk

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13 hours ago, Grum said:

Hi Rogue_Biker.

Noticed your picture shows your Fi light to be on! During the Starter Valve synch process your Fi light should display two error codes, one for they MAP Sensor and the other for the IAT Sensor.

Once you've completed the process and everything re-connected you should have NO Fi light indications. Are you sure you have electrically re-connected your IAT and MAP sensors, are all vacuum lines properly connected? Did you disturb any of the linkages from the Wax Pellet unit to the Starter Valves? Does the normal Idle Adjuster work in lowering Idle RPM?

Just tossing up a few ideas.

Good Luck.

Cheers.

Thanks for the response.

 

At the time I took that picture, I only had the MAP sensor connected, the whole airbox was still off and everything disconnected.  That probably explains the FI light staying on while I was trying to diagnose the idle

 

I cleaned and lubed the starter valve/Idle Unit linkages and confirmed they were all working as designed.  When I first start the bike when cold (with the MAP sensor disconnected), the bike idles around 1,400 RPM, then it drops to 1,100 RPM when it reaches 175 degrees F coolant temp.  So it appears the Idle Wax Unit is working to open the starter valves when cold.  It's been hot here in SoCal so when I say "cold" I mean cold engine.  It has been in the mid-70's in my garage when I work on the bike so the idle unit wouldn't normally rev the engine as high.

 

I confirmed the Idle Adjustment screw is working also.  I can't lower the idle any further than it is because the Idle Adjustment screw would simply "disconnect" from the plate that it pushes against as I keep turning the idle back.  

 

Since I've taken the airbox off about 5x now, I've memorized every single connection!  I know this is sad.  So yes confirmed.  All hoses in the right place, all electrical connections firmly plugged.  This little adventure now makes it very easy for me to remove my whole airbox by simple memory!  

 

It is entirely possible I disturbed the start valve/Idle unit linkages and hoses.  But since the bike idles fine when the mechanical parts are connected, and only revs up when the electrical MAP sensor is connected, leaves me to believe the linkages are fine.  

 

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16 hours ago, BusyLittleShop said:

If you experience high uncontrolled idle suspect an air leak... on a
fuel injection system *any* air that gets past the throttle bodies the
map just adds the corresponding fuel... the result is high
uncontrollable idle... make sure all the rubber hoses are connected
and in good shape... make sure all the intake boots are tight and in
good flexible shape... if the rubbers are hard and cracked its time
for replacement...

gallery_3131_51_651212.jpg

 

I believe this could be my idle issue.

 

I say this because I'm 99% sure I've eliminated the mechanical function of the starter/Idle Unit (One can never be 100% until it's fixed).  Since the MAP sensor ONLY gets input from vacuum, and the the only time the idle is uncontrolled (perfect description of my bike's condition) is when I hook up my MAP sensor, and it's a new MAP sensor, that leaves only the vacuum source to be wrong.  Too little vacuum because there is excess air being sucked in somewhere?  

 

Your comments above does reinforce my theory.  Although I'm still concerned because this condition suddenly materialized during the sync job.  So I'm not ruling out other possibilities completely.  If nothing else, I've learned a lot about how my throttle body works and how the starter valves & Idle Unit works.  Never had a problem with my VFR before so I'm not used to working on it much beyond normal maintenance.

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14 hours ago, Sweeper said:

When we did the sync on my 07 at the Spring Ride, the idle came up and would not back down. After a lot of inspection, it was the threaded end of the idle cable at the throttle bodies had frozen. We only thought it was all out. A little WD soak and it backed on down.


Sent from my iPhone using Tapatalk

 

This is possibly another part of my problem.  It's not easy to turn this adjustment screw!  I will re-check this tonight and definitely lube the mechanism.  I did observe the screw pushing against the starter valve plate, and when I turn the screw back out, it disconnects from the plate completely and the idle hangs up high.

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  • Member Contributer

As others have commented, check all your rubber hoses; there is a forest of them under the TB's, and the comment that you were unable to balance the SV's suggests that at least one hose is off/holed. Someone else had an issue with the hose off to the flapper mechanism which gave similar symptoms.

 

 

vfr hoses.png

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51 minutes ago, Terry said:

As others have commented, check all your rubber hoses; there is a forest of them under the TB's, and the comment that you were unable to balance the SV's suggests that at least one hose is off/holed. Someone else had an issue with the hose off to the flapper mechanism which gave similar symptoms.

 

 

vfr hoses.png

 

Agree on the forest of hoses (I have the California type) underneath the throttle body.  I've only replaced the hoses coming from the TB to the 5-way post, to the MAP, as well as the flapper valve hose.  It's amazing how much more tight the newer hoses are compared to the 10+ year old ones!

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  • 2 weeks later...

Update:  Last night I worked on the bike after finally receiving some of the parts I ordered from Partzilla.  Pissed that these guys.  I paid for 2-day expedited shipping and it still took them a f****'n week to deliver to my door.  WTF!  I just haven't gotten the energy nor the time to even call them up and demand a refund of the extra $2!!

 

Ok....whew!  Calm down.

 

I removed the Throttle Body.  Wasn't as bad as I thought it would be.  Thank you to KaldecBoc's YouTube video who suggested I use a piece of wood to lever the TB off their air boots.  Worked like a charm as the TB's popped right out.  I also discovered that at least 2 of the air boot's LOWER band screws were loose.  This could explain why I may have an air leak, which also explains the Synchronizer tool's vacuum reading on one of the cylinders reading a low vacuum.

 

Ironically, the "old" air boots were all in very good shape (after 10-years and 49k miles).  Like new in fact but just dirty.  I cleaned them up and they came out looking new.  Must be due to the mild, dry, Southern California weather the bike has lived in all its life.  But meh.  I replaced them with the new ones I got anyway.  Tonight I install a new thermostat and clean the throttle body a bit.  Then, I'll find out if this fixes my high idle.

 

 

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Update:  SUCCESS!!!

 

So indeed I had a major vacuum leak (or leaks) from the boots.  After installing the new boots and the new thermostat (unrelated to the high idle but since I already had the throttle body out I figured I may as well replace this), I started the bike up and....damn!  High idle persisted!!!  It wasn't until I REALLY tightened the air seal boots did the leaking stop and the idle came back down to normal.  Many thanks to all who made suggestions.  Busy Little Shop was spot on regarding the diagnosis.  Duc2V4, thanks for putting up with my incessant ranting about this issue for weeks!  LOL!  You also called it way back in the beginning.

 

I rode my VFR800 for the first time in almost two months of waiting for parts, wrenching on weekends to try to figure this out.  I put a few new parts to refresh my bike, cleaned fuel injectors, new CCT's, new chain and sprockets, and she is purring like a kitten.  I can't even remember the last time she ran THIS good.  Smooth throttle response at ALL speeds.  Smooth power delivery.  The VTEC is almost imperceptible when it engages at part throttle.  This is the way the VFR800 VTEC's are supposed to run from the beginning!  BTW, I have Power Commander 5 and O2 Eliminated, but still rocking the Flapper Valve and the PAIR.  I like the Flapper Valve and snorkel in place.

 

Going for a long ride tomorrow for a shakedown run.

 

Thanks all! 

 

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  • Member Contributer

Well, I have my moments. Glad this was resolved, I was getting sad that I never get see your marvelous RWB anymore. Not that the CBR and DR aren’t marvelous, the RWB is just a a gorgeous piece of machinery!

 

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