idle speed and TBS sync issue - Stromtrooper Forum : Suzuki V-Strom Motorcycle Forums
V-Strom Service and Maintenance Questions and Discussions Share your service and maintenance information-questions. Please include your year and model in the text of your post.

 
LinkBack Thread Tools Display Modes
post #1 of 10 Old 09-26-2009, 06:59 PM Thread Starter
Junior Trooper
 
Join Date: Sep 2009
Posts: 5
Unhappy idle speed and TBS sync issue

Hi to everyone,
This morning I decided to perform my first TBS job. I first changed the oil (and filter), replaced the clogged air filter and also put it new spark plugs. I hooked-up the two hose extensions with the caps on and warmed-up the engine. I tried to bring the engine to 1500 rpm as required but just after 1300 rpm or so the engine would rise to 2500 rpm. I tried again by unscrewing and screw the idle screw . Nothing. Playing with the handlebar throttle would get the rpms stuck even higher. Point is that idle speed can't stay above 1200 rpms without being affected by the handlebar throttle. I decided to try the TBS job anyway. I made fine adjustment until I could get the same reading. After opening and closing the throttle the readings would be uneven again. The bike runs bad as before: it stalls, it is not responsive at all and occasionally it backfires.
The bike is a 2004 model and the idle screw has always behaved like that (and I had to get use to a lower idle rpsm I guess).
What shall I check before trying to perform a TBS? I've read in these months many post about secondary plate, intake air sensor, intake air temperature and so on. What should be checked /adjusted before working on the TBS?
Could the following routine be correct?

1)Throttle Position Sensor check
2)Secondary Plate Valves sync
3)And then TBS?
As far as I remember the idle screw acts on the primary plates. I thought that FI bikes had an electronic idle speed system...I fear some relationship between the idle speed problem and the hieratic vacuum values...
Any suggestion is greatly appreciated!
Cheers,

C.
stroming is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 09-27-2009, 05:03 AM
Stromthusiast!
 
Austin44's Avatar
 
Join Date: Jul 2008
Location: Chicago
Posts: 657
Quote:
Originally Posted by stroming View Post
Hi to everyone,
Could the following routine be correct?

1)Throttle Position Sensor check
2)Secondary Plate Valves sync.
2B) Warm engine to regular running temperature - 3 bars!
Quote:
3)And then TBS?.
Yes. And:
4) Re-check possible change in Throttle Position Sensor.

Backfire ( explosion/pop from the throttle body) AND the inability to get an expected change
from the idle adjustment could be due to a vacuum leak. Are your throttle body boots properly
seated and tight?

How many miles on your K4 DL (1000/650?)? Have the valve clearances been checked? Valve
clearances are reduced with wear, seriously restrict engine breathing at less than proper
tolerance, and could lead to the bad performance effects you describe.

Quote:
As far as I remember the idle screw acts on the primary plates. I thought that
FI bikes had an electronic idle speed system.
The idle screw effects the opening of the primary plates (AIR supply) and the electronic FI
attempts to adjust the FUEL supply to a programed ratio. Adjust the air intake to adjust
the idle speed. An air leak will result in erratic FI performance.

Valves that don't open wide enough, long enough, will confuse manual adjustments or
electronic FI operation.

Austin

2002 DL1000 - 70K of joy, so far...
1978 GS1000 - One owner, still putt'n
Austin44 is offline  
post #3 of 10 Old 09-27-2009, 06:43 AM Thread Starter
Junior Trooper
 
Join Date: Sep 2009
Posts: 5
Thanks Austin for the prompt reply! The DL 1000 '04 has 24 000 miles on it. I believe it has not done a Valve check in the past at least 10 000 miles.I am positive though that the idle screw issue was there from day one in a way or another. The first time Suzuki dealer serviced the bike they said they did not find any issue with that. At that time I complained that setting the idle speed to 1300+/- rpms would occasionally end up with a 2000 rpms engine at the red lignt after riding it normally (and after a 5-10 seconds it would rev down by itself).
I guess I'll have to remove the tank again and check for air leaks. Now that I think about it, I did not put any oil on the gasket of the new air filter. Maybe I am getting extra problems from that (air leaks and so on). I don't have the service manual handy right now but can TPS adjustements be made without having to run the bike again to recheck it? Is it just a matter of unscrewing the tamper proofs torx bolts and gently adjust the sensor till I get the centered bar?
The only thing thats scarries me is that we don't have here in Itay stores like Sears where you can find at once all the tools you need..
Cheers and thank you again.

C.
stroming is offline  
 
post #4 of 10 Old 09-29-2009, 05:35 AM
Stromthusiast!
 
Austin44's Avatar
 
Join Date: Jul 2008
Location: Chicago
Posts: 657
Quote:
Originally Posted by stroming View Post
At that time I complained that setting the idle speed to 1300+/- rpms would occasionally end up with a 2000 rpms engine at the red lignt after riding it normally (and after a 5-10 seconds it would rev down by itself).
You are right. Idle should be 1200-1300 rpm on the DL1000. Mine works flawlessly after
TPS adjustment and resetting to about 1225 rpm.

Here's a Suzuki video, a different model, but the same procedure:
http://www.vstrom.info/Movies/TPS_TB_Tuning.mpg

You have a PM.

Austin

2002 DL1000 - 70K of joy, so far...
1978 GS1000 - One owner, still putt'n
Austin44 is offline  
post #5 of 10 Old 09-29-2009, 10:08 PM
$tromtrooper
 
larolco's Avatar
 
Join Date: Oct 2006
Location: Langley, BC, Canada
Posts: 2,351
If you set the idle too high, it will climb like you describe. Try a slightly lower idle rpm setting. Mine tends to settle in around 1100.

Messing with the idle while doing the TBS can be a real pain.

DL1000K6 Two wheels good; four wheels bad.
DRZ400SK17
larolco is offline  
post #6 of 10 Old 10-24-2009, 03:12 PM Thread Starter
Junior Trooper
 
Join Date: Sep 2009
Posts: 5
Question STP, TP, Fast idle, IAT, STV,TBS checked and still no luck

Sorry for posting after so many days but I haven't had a chance to work on the bike before. I have removed the throttle bodies for inspection of the boots expecting to find a crack (or loose boots) since the engine would constantly backfire after releasing throttle and mileage was awful. I didn't find any cracks so I decided to go thru the entire process of STP adjustment (it was far from being correct) and also fast idle one (this one also was 0,2 volts out of range). I checked the Intake air Temperature sensor and found it to be within specs as well as the engine coolant sensor. I did not have gauge to check the intake air pressure sensor resistance but the right voltage is being delivered. I went thru checking the spark plugs and I found that the front cylinder one was fouled (black color). I would assume rich mixture being nebulized. The rear one looked light brown which I assumed was ok. I also checked the injector resistance which was within specification though i did not remove them as I had read in the manual that a little seal or o-ring replacement was mandatory after inspection.
I also adjusted the secondary plates though I had to tighten all to the way down the screw in order to have the front plate as closed as the back one (0.55 mm,0.216 inch approx checked using a feeler ).I put everything back together and started the engine. idle speed was very hard to set at 1200 in order to proceed with TBS. The engine would ramp up to 2500 rpm (fast idle cam doing it of course) and then untightening the idle screw would bring it down but never in a constant pattern. I managed to sync the bike using a home made manometer filled up with about 24 inches of two strokes oil connected with the extensions pipes to the throttle bodies by the way:does it make any difference which nipples I use? rear cylinder has two available and front cylinder has one connected to the dampening IAP thing). I had to readjust the idle down to 1000 rpms otherwise quick strokes of the throttle would bring idle speed at 2000-2500 rpms). Took the bike for a ride and it ran much better but the engine lacked power and idle speed would not be constant. The bike would occasionally backfire (not as bad as previous days) and the FI red light appeared just before getting home. I checked the codes using the dealer mode trick and it said C00. The TP sensor was out of adjustment although it had been adjusted today. I readjusted it twice while having the bike warm (two-three bars) as it would go either above or bellow the center line.
I went thru TBS procedure once again and decided to check it at different ranges of rpms.It was not as accurate as minutes before but maybe I was not idling the same way (I am not using a digital tachometer,but just the bike own instrument).I revved the engine manually by just opening the throttle a little bit and noticed that the TBS changes by 5 inches! Is that normal? I tried this with and without secondary plates, same deal. How can one cylinder "Pull" more than the other one with plates removed thus leaving only the throttle to regulate the amount of air being sucked in ? Maybe combustion does not have same efficiency on front and back cylinder. I don't know what else to check before investigating fuel pump pressure issues (how), dirty injectors or valves out of clearance (24 000 miles and haven't checked them yet; cannot assume shop did it last time I took the bike 6000 kms ago). I thought also about a defective PAIR solenoid (can this be inspected?) or even a coil but I believe that the front spark plugs being fouled with black residues might be a clue.
The ST actuator also doen't convince me at all: it takes like 8-10 seconds to bring back idle speed when it uselessly rises it to 2/3000 rpms. ALso when the bike is finally idling at 1200 rpms or so, I can see the STV linkage being "nervously" operated by the actuator which constantly tries to adjust things (maybe this is normal, I'm just trying to provide as many details as I can).
Any suggestion is greatly appreciated as riding this bike really makes me miss carburetors motorcycles.
Cheers to all.
cam

Last edited by stroming; 10-24-2009 at 08:12 PM.
stroming is offline  
post #7 of 10 Old 10-25-2009, 06:58 AM
Stromthusiast!
 
Austin44's Avatar
 
Join Date: Jul 2008
Location: Chicago
Posts: 657
Quote:
Originally Posted by stroming View Post
I checked the Intake air Temperature sensor and found it to be within
specs as well as the engine coolant sensor. I did not have gauge to check the intake air
pressure sensor resistance but the right voltage is being delivered.

by the way:does it make any difference which nipples I use? rear cylinder has two available and
front cylinder has one connected to the dampening IAP thing).
Whoops! I think the rear cylinder should only have one port (nipple) available. The other one
is connected to the PAIR control valve (exhaust emission) vacuum hose.

The Intake Air Pressure sensor (IAP) vacuum hose is connected to a port (nipple) on
the front throttle body.

You should have only one port available on each throttle body for the extension hoses.

Austin

2002 DL1000 - 70K of joy, so far...
1978 GS1000 - One owner, still putt'n
Austin44 is offline  
post #8 of 10 Old 10-25-2009, 10:58 AM Thread Starter
Junior Trooper
 
Join Date: Sep 2009
Posts: 5
Hi Austin,
The back cylinder has two nipples available both with a cap on it. I connected the hose to the one that is further close to the right side of the bike (back brake pedal side). The front cylinfer has one nipple available protected by a cap and it is on the left side of the bike (sidekick stand side). The other nipple is connected to a hose which is connected to the dampening cylinder which then connects to the intake air pressure sensor. Assuming that the bike has not been messed up last time it has been serviced the set up looked fine to me. I double checked on the service manual and you can really see the two nipples on the back cylinder. The picture is not as clear on the front cylinder but again, since the Intake air pressure is connected on one nipple, it must be the other one. I don't know what else to do to make the bike run right. I am going to measure the amount of fuel delivered by the pump to exclude pump/filter issues.
I wonder if the PAIR system can be involved somehow in the lack of power but I guess the solenoid valve interferes only with the exaust system pumping in fresh air for emission issues. What really seems strange to me is the inconsistent behaviour which really makes it hard to track down problems.
Ciao!
[IMG][/IMG]
http://img2.imageshack.us/i/tbsconnections.jpg/

Last edited by stroming; 10-25-2009 at 01:49 PM. Reason: added pic
stroming is offline  
post #9 of 10 Old 10-26-2009, 05:50 AM
Stromthusiast!
 
Austin44's Avatar
 
Join Date: Jul 2008
Location: Chicago
Posts: 657
Hello, Stroming

Quote:
Originally Posted by stroming View Post
I went thru checking the spark plugs and I found that the front cylinder one
was fouled (black color). I would assume rich mixture being nebulized. The rear one looked light brown
which I assumed was ok.
This indicates the front cylinder is running too rich, compared to the back. The back might have an intake leak
or the throttle plates are way out of synch. Could also be the sparkplug was not seated (grounded).
The sparkplug insulators on my K2 looked a very light tan at 21,000 miles.

Quote:
idle speed was very hard to set at 1200 in order to proceed with TBS. The engine would ramp
up to 2500 rpm (fast idle cam doing it of course).
The fast idle (cold start idle) on my K2 drops when the bike gets to ONE temperature bar. It should have
the clearance between the adjusting screw and the stop tab, as shown in the manual, once the bike is
warmed to TWO bars. The TBS is best done with the gauge showing THREE temp bars, that is, at
actual engine operating temperature. I wait until the fan comes on before beginning TBS.

Quote:
I had to readjust the idle down to 1000 rpms otherwise quick strokes of the throttle would bring
idle speed at 2000-2500 rpms).
Quick response to the throttle is a good thing. When I first did the TBS, my idle was set at 1000rpm.
No joy. Reading on this and the other forum convinced me to use 1250rpm ( Estimated, I'm just using
the bikes tach )for regular idle and for all adjustments. I had to turn the idle down after the first
attempt at TB synching. After re-synching, I had to turn it down a little bit again.

I've read here that 10" of lightweight oil movement is equivalent to 1" of movement on a commonly used
mercury manometer. Sensitive. I can't get stable oil levels closer than 1" at 1250rpm. I've left it with the
front about 1" higher, so the rear would experience the slight richening effect.

Quote:
I readjusted it twice while having the bike warm (two-three bars) as it would go either above
or bellow the center line.
The TP sensor setting should be the same whether the bike is hot or cold. A mechanical position sensor,
which sends an electrical signal. As you can read on the forums, this sensor can be the cause of a variety
of specific operating woes and testing with a Volt/Ohm meter doesn't always show a problem. Replacement
is the only reliable test, unfortunatlely. I wouldn't replace it unless all else fails.

Quote:
I revved the engine manually by just opening the throttle a little bit and noticed that the TBS
changes by 5 inches! Is that normal? I tried this with and without secondary plates, same deal. How can
one cylinder "Pull" more than the other one with plates removed thus leaving only the throttle to regulate
the amount of air being sucked in?
You only see the DIFFERENCE in vacuum with a homemade manometer. As engine rpm's increase, actual vacuum
increases greatly compared to low vacuum at idle. 5 inches is a significant difference at idle rpm and low
vacuum. It's insignificant at higher rpm's and high vacuum.

Quote:
The ST actuator also doen't convince me at all: it takes like 8-10 seconds to bring back idle speed
when it uselessly rises it to 2/3000 rpms.
The ST actuator can be in constant motion at all rpm's. It is the attempt by the ECU at fine tuning. If your
engine is fully warmed (three bars of temp), 8-10 seconds to return to idle speed of around 1200rpm would
indicate that one cylinder is running much leaner than the other at the current idle screw setting.

The reported causes for this are vacuum leaks, unsynchronized Secondary Throttle Plates, out of balance
Primary Plates (TBS) and out of specification valve openings.

Quote:
Any suggestion is greatly appreciated as riding this bike really makes me miss carburetors motorcycles.
Cheers to all.
cam
I still own and ride a carbureted inline 4. If I could replace with FI, I would do it in a minute. Carburetors
need synching and adjustment every few thousand miles, and are oversensitive to temperature, altitude,
fuel quality and wear.

Since you have dealt with STP, TBS and TPS but still have problems, and since 24,000 miles is overdue
in any case, I suggest that you check valve clearances. Let the engine sit 24 hrs. first, completely cold.

Day before I checked mine, I checked STP, TBS and TPS. They were right on after 11,000 miles. I've been
at the darned carburetors of the inline 4 twice in the same time period because they needed it!

I checked and replaced shims at 22,000 miles. All were at the very low limits of clearance. I replaced all
8 shims one size down to get within the upper limits of clearance. I don't expect a problem until 50,000
miles. After shimming, my STP adjustment was still right on, as was the TPS. I only needed to re-do TBS.

My K2 was running strong and smooth before valve check, and is running well now. I love this bike. I hope
you can solve your problems and have the enjoyment this machine is so capable of delivering.

Austin

2002 DL1000 - 70K of joy, so far...
1978 GS1000 - One owner, still putt'n

Last edited by Austin44; 10-26-2009 at 05:59 AM.
Austin44 is offline  
post #10 of 10 Old 10-29-2009, 06:11 PM Thread Starter
Junior Trooper
 
Join Date: Sep 2009
Posts: 5
Thumbs up Inconsistent IDLE speed, lack of power SOLVED!



Hi all,
One cylinder would run fine for a few second and then it would run lousy. Switching injectors would't help (problem shown on same cylinder). Nebulizing fuel in the cylinder using a medical syringe would make the cylinder run fine for a few seconds at least. Guess what: the fuel delivery pipe was clogged with rust and dirt! (how the hell did it pass thru the filters)
Now the bike seem to run fine and consistent. I'll test it this week-end and get back to you.
I am afraid of servicing the tank as I fear I might result in more trouble than good (I read here and there that filters are 10 times more expensive than car ones altough a bypass is possible in order to use external car filters).
I know this is out of topic but is it possible to mount in series a potentiometer to winterize/summerize the readings from the IAT sensor in order to obtain a slighly richer or thinner mixture?
Cheers to all and thank you Austin for your suggestions. By the way: valve are still within clearance.
stroming is offline  
Sponsored Links
Advertisement
 
Reply

Tags
fast idle , idle screw , stva , tbs

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Stromtrooper Forum : Suzuki V-Strom Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome