Default settings on the secondary air-intake regulator

[Rune56]

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?

[Tally]

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.

[KiwiCol]

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.

[Hooli]

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.

[grog]

Just a stupid question, makes no sense. 😂

[Rune56]

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.

[Eric GSX1400K3]

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.

[Rune56]

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.

[Hooli]

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.

[KiwiCol]

I think @Snapey would have an answer for you on this, I know he did a fair bit of work on his.

[Rune56]

@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.

[Hooli]

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.

[Eric GSX1400K3]

I had similar that 1 and 2 were not closing the same as 3 and 4, the adjusting screws between them sorted that out.

[Horse]

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

[Kiwifruit]

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.