Need help with ISCV

[Kenneth67]

Hi guys, I need a little help with my ISCV if anyone wants to volunteer?

Basically the bike will run fine with throttle open a shade even just 2%, but will not idle. Just bogs and dies.
I've been reading on here about how many others have issues with TPSs and so forth.

I have;
1. Reset ISCV - primary TPS set to 0.60v and then adjusted ISCV until TPS read 0.72v. No difference.
2. Sprayed WD40 in under ISCV rubber boot and all in around the throttle springs etc. No difference.
3. Replaced primary TPS with new one, set to 0.60v etc etc. No difference.
4. Replaced ISCV with new one, set TPS to 0.60v and then adjusted new ISCV until TPS read 0.72v. Also ran the ISCV test in tuneboy. No difference.
5. Replaced MAP sensor with new one and new vacuum tubes. No difference.
6. I run a PC5 so I updated the firmware and reloaded the map. No difference.
7. I reloaded the ECU map and checked idle speed setpoint. No difference.

The bike ran fine for years and suddenly one morning this issue happens.

I'm all out of ideas at this stage but I did watch the ISCV when running and it doesn't do a whole lot.
I expected it to extend out a little to catch the revs as I let go of the throttle, but it doesn't.

Can I ask someone to make a video of what their ISCV does during startup and idling, especially after blipping the thottle please?
So I can compare. ANy volunteers?

Thanks
Ken

 

[warp9.9]

Ok Ken first some of your wording sounds confusing at least to this Polock. So lets make sure you understand the ISCV reset and what it is (my view which is not from a phone app) First ISCV reset stands for idle stepper motor control voltage reset (Much like homing a mach and the tool its using) it is a manual adjustment and synchronizing or the idle stepper motor the Primary TPS (which in this process you can check your secondary TPS voltage to see how it is set.) All this stuff get synchronized so when you are in a cell or field on the map the throttle percentage matches. It also give a solid zero point (home position for the stepper motor?
First let me ask you a few questions about what you have above and let you digest my laymen s explanation of the ISCV reset.
1. was this done with a computer or a phone app? When you set the .6 volts was that with the stepper motor fully retracted (by the ecu) You can verify this by placing you finger on it when you click ISCV or watch the voltage change from what it is to when you clicked ISCV reset. This has to be right or the .12 voltage movement will not be in the correct relation to the map either. I suggest if you have messed with the stepper motor adjustment a lot the you should treat it like a initial stepper motor change and set the gap on the cam with a feeler gauge as the book states. (this gets you into the ball park voltage movement gap when you actually change a stepper motor)
4. Replaced ISCV with new one, set TPS to 0.60v and then adjusted new ISCV until TPS read 0.72v. Also ran the ISCV test in tuneboy. No difference.
I am sorry but this sentence makes no sense what so ever can you read it and translate (how can you change a electrical test?) I see you use tune boy good product bad support much better using Tune edit then Tune ecu IMO if you want to know what all your sensors are doing. Not kicking Tune edit it is good also.

5. Replaced MAP sensor with new one and new vacuum tubes. No difference. Good your replaced the lines did you replace the four vacuum plug caps while you were at it?
Your on a good route here did you also chase down each low tension lead on the coils (these would be the little 12 volt ones) pictured below

These bugger work loose a little squeeze of the female spade connector so she is good and snug going back on will fix some amazing stuff on the bike we will not talk about how long it took this Polock to figure His bumbling running of his bike out until he did this.
anyway you digest ask away and I will pull a grenade and jump back up in the attic as the insulation will not lay itself
I'll check back

 

[Kenneth67]

Ok Ken first some of your wording sounds confusing at least to this Polock. So lets make sure you understand the ISCV reset and what it is (my view which is not from a phone app) First ISCV reset stands for idle stepper motor control voltage reset (Much like homing a mach and the tool its using) it is a manual adjustment and synchronizing or the idle stepper motor the Primary TPS (which in this process you can check your secondary TPS voltage to see how it is set.) All this stuff get synchronized so when you are in a cell or field on the map the throttle percentage matches. It also give a solid zero point (home position for the stepper motor?
First let me ask you a few questions about what you have above and let you digest my laymen s explanation of the ISCV reset.
1. was this done with a computer or a phone app? When you set the .6 volts was that with the stepper motor fully retracted (by the ecu) You can verify this by placing you finger on it when you click ISCV or watch the voltage change from what it is to when you clicked ISCV reset. This has to be right or the .12 voltage movement will not be in the correct relation to the map either. I suggest if you have messed with the stepper motor adjustment a lot the you should treat it like a initial stepper motor change and set the gap on the cam with a feeler gauge as the book states. (this gets you into the ball park voltage movement gap when you actually change a stepper motor)
4. Replaced ISCV with new one, set TPS to 0.60v and then adjusted new ISCV until TPS read 0.72v. Also ran the ISCV test in tuneboy. No difference.
I am sorry but this sentence makes no sense what so ever can you read it and translate (how can you change a electrical test?) I see you use tune boy good product bad support much better using Tune edit then Tune ecu IMO if you want to know what all your sensors are doing. Not kicking Tune edit it is good also.

5. Replaced MAP sensor with new one and new vacuum tubes. No difference. Good your replaced the lines did you replace the four vacuum plug caps while you were at it?
Your on a good route here did you also chase down each low tension lead on the coils (these would be the little 12 volt ones) pictured below

These bugger work loose a little squeeze of the female spade connector so she is good and snug going back on will fix some amazing stuff on the bike we will not talk about how long it took this Polock to figure His bumbling running of his bike out until he did this.
anyway you digest ask away and I will pull a grenade and jump back up in the attic as the insulation will not lay itself
I'll check back

Thanks warp9.9 I do all this work with computer and tuneboy.
The TPS voltage is like 0.68 or 0.69 when I start up tuneboy, then when I hit reset ISCV button the TPS goes back down to 0.60v as the ISCV buzzes back home.
Then when I hit reset ISCV again it extends out a little and I can adjust the little nut to get 0.72v on the TPS.
The nut is in pretty much the same position on the stepper rod as the original ISCV nut was.

In #4 I meant I replaced the ISCV and it is working fine according to tuneboy.
And then I did the ISCV cycle test in the "tests" page of tuneboy. You can also cycle the fuel pump and some other stuff in there.

I didn't replace the 4 little throttle body plugs, but they look good still.
I'll give the low tension spades a squeeze like you say, hopefully that will help. Thanks.

 

[ThisGuy]

I might be picking nits here, but as someone closely following along who will be doing all of this shortly, it'd be helpful to try and keep to the correct terminology to reduce confusion as much as possible.

First ISCV reset stands for idle stepper motor control voltage reset

Doesn't it stand for Idle Speed Control Voltage? Basically the same thing as it controls the stepper motor… it's also referred in the service manual as the ISC Stepper Motor… just trying to keep to uniform phrasing to help people searching the forum in the future. Actually, didn't really need to ask this question. I really just wanted to post the phrase Idle Speed Control Voltage so the thread shows up in searches.

as the ISCV buzzes back home

I meant I replaced the ISCV

Do you mean the Stepper Motor? The ISCV isn't a part, it's the control voltage sent to the part.


Again, not trying to annoy anybody, just trying to keep the terms straight and reduce confusion for other beginners like me who will be using these threads to figure out what's what.

 

[warp9.9]

I might be picking nits here, but as someone closely following along who will be doing all of this shortly, it'd be helpful to try and keep to the correct terminology to reduce confusion as much as possible.



Doesn't it stand for Idle Speed Control Voltage? Basically the same thing as it controls the stepper motor… it's also referred in the service manual as the ISC Stepper Motor… just trying to keep to uniform phrasing to help people searching the forum in the future. Actually, didn't really need to ask this question. I really just wanted to post the phrase Idle Speed Control Voltage so the thread shows up in searches.

Ok I pulled two grenades and did a little reading I I think you are confusing two different things. I can not swear by it but. I believe there is the ISCV reset which is homing and insuring the distance between the cam and roller are correct. this is just initialization. Idle Speed Control uses a multitude of calculations and and vairiables in the process of loading changing parameters to decide the right voltage to send to the idle stepper motor which was homed during the ISCV. IF you understood and can understand Tool compensation and axies homing of a CNC machine and its controller. Especially when it comes to variables that change. Air temp Vacuum load altitude, O2 sensor readings if yours is on. all this info is compiled into a parametric equation/s to decide what voltage to send to the idle stepper motor. Even long and short term fuel trim adaptations can effect this.
Either way I believed he changed the stepper motor also after everything else he tried. but I am just speculating right now.

 

[Speedy]

What is the MAP sensor reading when you hold the throttle at that 2% open? You monitor this from either of the test screens. Are the TB's synchronized? If the MAP reads much more than 620 or the spread between throttle bodies is more than 30 you may have a leaky TB boot or a coil problem. What is the lowest rpm it will run by holding the throttle by hand? If you can pin point a cylinder that runs different than the others it may lead you towards the problem's solution.

 

[Jag]

What is the MAP sensor reading when you hold the throttle at that 2% open? You monitor this from either of the test screens. Are the TB's synchronized? If the MAP reads much more than 620 or the spread between throttle bodies is more than 30 you may have a leaky TB boot or a coil problem. What is the lowest rpm it will run by holding the throttle by hand? If you can pin point a cylinder that runs different than the others it may lead you towards the problem's solution.

I just balanced my throttle bodies 620/630 runs great, but with an occasional intake backfire. Has always had an intake backfire from new. So I'm guessing from what you have said, I may have a boot problem?

 

[Fingers]

@Jag ,try taking the bear law off and spray water ( with a small spray bottle)around each boot .The rpm's should change when you find the defective area.

 

[Kenneth67]

Spade connectors on LT wires feeding coils are nice and tight.

What is the MAP sensor reading when you hold the throttle at that 2% open? You monitor this from either of the test screens. Are the TB's synchronized? If the MAP reads much more than 620 or the spread between throttle bodies is more than 30 you may have a leaky TB boot or a coil problem. What is the lowest rpm it will run by holding the throttle by hand? If you can pin point a cylinder that runs different than the others it may lead you towards the problem's solution.

I get about 705 each cylinder on tuneboy. TBs balanced well, but it appears to be pulling more of a vacuum than normal. I wonder does that mean throttle is closed too far and is starving the engine of air. Which would give a rich mixture.
And there is indeed a smell of petrol in the intake and the exhaust is quite sooty so that means it is indeed running very rich and would explain why it is bogging at idle.

I took a look at the throttle plates and cycled the secondaries which seem ok.
They are open more than the primaries.

WHat I'd like to know is how "open" the primaries should be at 0% throttle??

Thanks guys

 

[Speedy]

Quite the opposite. At 705 your vacuum is lower than normal. The throttle blades are open more than normal. Something is making your engine "work" harder to keep running. Anything that affects timing can do this as well as a cam that has jumped a tooth. Can also be a large vacuum leak. Start with a timing check which you can do by monitoring on Tuneboy. You can watch the timing for each cylinder while the engine is running. Coil saturation time should be close across all the cylinders as well. The timing should be close to what is in the neutral timing table for that rpm. Then wiggle hoses and the entire throttle body assembly to see if the MAP reading changes. If it does you have an air leak. If you still find nothing, and the tune is not screwed up, your problem is more serious. Check one thing at a time. Good luck.