Hi there!
Im new to the forum and I haven't seen any topic that covers my question. I want to know how I could mechanically change the settings to default om my secondary air-intake regulator?
Hi rune56 and welcome to the forum. May I point out that it is customary for new members to announce themselves in the introductions section of the forum before posting questions. Tell us who you are , what country you are from and which model bike you have, i.e k2,k3etc which colour scheme you have and pictures, we like lots of pictures and finally someone on here is bound to have the answer you're looking for. :welcome1:
Gidday Rune56, welcome to the forum. Yeah, some more intro details would be a good idea.
As for your question, can't say I've ever heard that one come up before, maybe the way you've worded it is throwing me off, I'm not really understanding what you're trying to rectify.
I don't understand the question either.
Is it do with the secondary throttles? if so then if the TPS & STPS are set correctly then the ECU knows where the STVA stepper motor is & puts it in the right place.
Just a stupid question, makes no sense. 😂
Hi to you all! And thanks for the replies :)
Im norwegian and my son is translating for me, therefore there might be things lost in translation. Apologies for bad grammar and wierd choices of words. As for the introduction I'll make a post later today when my son is finished with his school day.
I belive
@Hooli is close to what Im asking about. I've had trouble with my bike for three years now. When I turn the throttle the engine misfires for one second and almost jumps/snaps instead of evenly increase the speed. The engine is hot when this happens. Im used to fixing engines and somewhat familiar with problemsolving. I've changed every electrical components and sensors and cant find any error. I've also calibrated everything that is mentioned in the suzuki manual. The next thing I've yet to try is the secondary throttles, which I belive might be set wrong from the suzuki bike plant.
So, to clarify what I'm asking here: Is there a way for me to check that the secondary throttle is set correctly? Not the stepper motor which adjusts it, just the secondary throttle. And if my translation still dosen't make sense: if you translate the thing directly to english the word that comes up is a damper, but i belive this is just a norwegian word and might not make any sense to english-speaking people.
And if I should try to change the way it is set, should I use the middle adjustment-screw which is placed on the stepper engine? Or ohm the stepper engine? How to they do this in the manufacturing plant?
I hope this clarifies it some, and if not I'll give it another try later today. I've got a K3 bike and has only 11.000km in 19 years.
Hi Rune, the usual route is to ensure thr battery is fully charged ir connect to a power source. Check and ensure the jdle speed is 1100rpm. balance the throttle bodies, using #1 cylinder as a reference, and setting #2 to match, then #3 and #4. You will need a 4 channel vacuum gauge for this. Then check the (primary) throttle position sensor by measuring its voltage fully closed and fully open, you can reach in underneath the throttle bodies to actuate them. Same for the secondary throttle, but then you need to reach in via the airbox to actuate those. The required settings (volts or ohms) are in the manual. Recheck the balance between the throttle bodies, they should all read the same vacuum. Adjustment is via the set screws. I also check the offset between #1and #2 cylinders to #3and#4, this is controlled by the linkage between thr two pairs.
Sounds to me though you could also have a vacuum line issue, have you checked that all vac lines are OK and not brittle or broken? Usually the PAIRS valve block is a good mod, can also cause hiccup a d fuelling issues. Failing that, check your fuel pump and its pressure regulator.
Hope this helps.
Hi Eric!
Thank you for a thourugh response :) I've already done what you are suggesting, but with no luck. I've removed the PAIRS completely. All other vac lines are ok. I've also syncronized the throttle valves. I've ajusted the TP and STP sensor. Tomorrow I'll open the STV servo to check if it works 100% correctly. I'm really stuck because the service manual I use does not tell me how to fix or even check the thing that I'm after. I got the Haynes service and repair manual from 2009, and if you do too you can check 4-14, under secondary throttle valve servo (n. 48-51 in fat letters).
I've added some pictures of the "screw" that I'm asking about. I can press the valves down and screw it all the way down to a 100% closed position. Does anyone know how many rotations it should be "unscrewed" again to be like the default setting?
The two other calibrating "screws" seem to be in their right places.
No idea on the setting for that one. As far as I recall the official suzuki workshop manual, which you can get from the download section on here, says not to touch it as it's factory set.
There is a 'fast idle' screw you can access from the top that changes the secondary throttles too, but that also says to not change as it's factory set.
As you know the sensors are set right, is the cold idle about 1,800rpm for the first few seconds? if not then I'd try tweaking the fast idle screw to get that right and see if helps. The secondary throttle actuator turns backwards to control the fast idle, so it might affect what the ECU thinks is the normal position for it. I believe the ECU only knows where the actuator is by comparing the throttle sensors, it can't 'see' the actuator directly.
I think
@Snapey would have an answer for you on this, I know he did a fair bit of work on his.
@Hooli @KiwiCol Thank you for your time and responses. The fast idle screw is set correctly, and the cold engine idle is 1600 +/-100rpm (depending on the weather and such). I will try to contact
@Snapey, do you know if me tagging him in this post will notify him or should i write him personally in PM?
I've picked apart the picked apart the "carburator rack" (pictured above) today to check if I could find something wrong with the servo-engine. I could not find anything wrong, and putting it together with all the springs and stuff is quite more challenging than i first realized.
I've also adjusted the secondary throttles ("dampers") so that they are all locked/closed at the same time. They were not all aligned, and if Im lucky that might help, but Im not confident.
Again, thank you all for your responses. If I ever find the solution to this I'll post about it if you guys want.
I've just remembered something from years ago.
Your clutch switch isn't bypassed is it? I did that once when it failed & leaving it connected all the time changes the ignition map for easier starting, it made my bike backfire as I opened the throttle.
I had similar that 1 and 2 were not closing the same as 3 and 4, the adjusting screws between them sorted that out.
Looks like you have done a mountain of work to get to this point but the original description of the fault as a misfire , whist it could be fuel has an electrical problem been ruled out? Is the misfire at a consistent load / speed can you replicate it under different conditions? Not saying this is the case but just wondering if it's a hesitation or a misfire as I would think the throttle body adjustments would make for poor running and hesitation not so much a misfire. Some more info about the history of the fault and your diagnosis sequence might help get a resolution . If you have gone down all the other rabbit holes and this is the only one left , just ignore these comments
Good luck ,
Horse
For what it's worth, I had an intermittent engine running fault and I believe I somehow fixed it pulling apart and reconnecting electrical connections in the headlight.
Just a thought. I don't know the technical stuff you blokes are discussing.
@horse It could also be the mixure of fuel and air. Then I increase the throttle slowly from 2000 rpm it comes 1-2 hiccups. When I increase it really slow they disappear. I have used a dyno mapper, but it didn't give me any thing. The sparkplugs are more dark than they should (with sot in mind). The switch on the clutch handle worked before, but is now defective. I noticed no difference in the preformance of the engine. I have changed the fuel pump, filter and tested the pressure valve. The secondary throttles are calibrated for the second time. The rest I'll calibrate when I assemble it together again. It seems as if the problem gets bigger as the engine gets hot. Oil temp sensor is controlled and works as it should. I have checked all the electrical connections by using 5,5 volts using store bought batteries coupled in series. It might not be enough power to open or close the secondary throttle.
Could it possibly be that the injectors need to be cleaned? I've no idea whether this could cause the issue or not, but maybe a consideration?
I know you are based in Norway
@Rune56 but this is one of 'our' recommended companies in the UK for doing this, I guess there must be similar local in Norway.
https://gsx1400owners.org/forum/index.php?topic=95.0
So all you have is a stutter under acceleration? Have you, replaced spark plugs, tipped coil leads, had injectors cleaned? Clutch switch must work, if not sends a different MAP, you can here difference at idle pulling lever in/out. Cant see why youre worried about secondaries at a 2k rev problem.
The choke function on Suzuki FI of the time was not fully off until apx. 74deg C. In my opinion the big cooler is cooling the oil too much and I have covered the whole cooler to get temerature up. Even then I never see over 80 deg in normal riding conditions. I am on my 2.GSX1400, I had the first reg.d in Europe back in 2001. This was bored out to 1550cc with Yoshi ST1 cams/PC3/Yoshi 4-1 and 4deg advancer. Even on this one with fully covered radiator never had problem with overheating.
Sooty plugs leads me to think that the mixture is wrong.
Quote from: Rune56 on Sunday, 24 April 2022, 12:58 AM
@horse It could also be the mixure of fuel and air. Then I increase the throttle slowly from 2000 rpm it comes 1-2 hiccups. When I increase it really slow they disappear. I have used a dyno mapper, but it didn't give me any thing. The sparkplugs are more dark than they should (with sot in mind). The switch on the clutch handle worked before, but is now defective. I noticed no difference in the preformance of the engine. I have changed the fuel pump, filter and tested the pressure valve. The secondary throttles are calibrated for the second time. The rest I'll calibrate when I assemble it together again. It seems as if the problem gets bigger as the engine gets hot. Oil temp sensor is controlled and works as it should. I have checked all the electrical connections by using 5,5 volts using store bought batteries coupled in series. It might not be enough power to open or close the secondary throttle.
With the description you give I still feel it sounds like a miss which could be injectors but I would still tilt towards electrical , as you say if you accelerate hard it's worse that's classic electrical as the load is highest at low speed high throttle opening , besides an injector, fuel /air starvation usually does not cause a miss more a hesitation / loss of power. Hard to diagnose over the internet, that's why the fault description is critical as we are guessing what is actually wrong , after making sure the injectors are OK I would give the electrical side another look but you are there and should have a better feel for the fault
Horse
Rune56 you have a PM.
I have new injectors and cluch switch. I've checked all the connections in the front light. I also have new coils, cables and plugs. I've been through different workshops in Norway without any luck.
74 degrees sounds a little cold.
I've also bought new carburetors with servo and sensors. That was not a cheap ordeal. I'll assemble it the next couple of days. I'll post a new message if that fixes things. I've almost changed every part on the bike now.
Thank you all for your suggestions and I'll soon answer PM's I've recieved too.
I'VE FINALLY FIXED MY BIKE!
It took me almost three years, but now the bike runs as smooth as it should. The issue was either the clutch switch or the throttle bodies. Im not sure because I changed both of them at the same time. When I assembled the engine last night it had no delay. Now I can meet this summer head on and put this to rest.
The only warning I got was that the F1 light has turned on twice (C28 or C29, I cant remember. Both errors has to do with the secondary thottle valve servo or sensor). I've changed the throttle bodies, and the clutch switch. The rubber to the injectors are sealed tight, so no problem there. Vac lines are ok.
Thank you all for your suggestions and feedback. I'd like to thank the broader forum-community too for giving me both space and time, and not least tolerating my posts probably ridden with mistranslations and bad grammar. You guys are great.
Rune
Glad you got it sorted mate
Good result there.
Glad you got it sorted mate. :onya: