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Discussion Starter #1
Hi all. I have an 08 1000 in an open wheel racecar. Car / motor sat all winter and now idles around 2,300rpm. I have narrowed it down to air being drawn in by the ISC. I've removed the valve and verified it's not carboned up and it cycles when the ignition is turned on. My guess is that it's not fully extending and closing the port. Not sure if it's a valve failure or if the ecu learned the positions incorrectly. If I disconnect the battery for a while it it reset the learned positions and clear and fault codes? Do I need to replace the valve? It looks like a fairly expensive part so o dont want to just throw one if if it's not needed.

Like I stated the engine is in a "car" not a bike and I dont use the factory gauges so I cant read any fault codes.

Pics for attention!
Thanks for the help!


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What's the part number on your ECM? It should be something like 32920-21Hxx. My K6 doesn't have one of those new fangled ISCs so I have no direct knowledge. But I'm thinking that you could experiment by seeing what happens if you crimp the air hose (it may not start when crimped, i.e. you may have to do this while it's running).

Haven't checked recently but you used to be able to buy an SDS system for around $150 on AliExpress. It will read the codes, as well as codes for faults that have been corrected, and allow you to manually control and reset the ISC.

Yoshimura sells parts that blank off the ISC and adjust the idle so that you set everything manually, like on the K6. See 764-508-1000 and 799-508-0000. But I don't know why they would be required.
 

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Discussion Starter #3
What's the part number on your ECM? It should be something like 32920-21Hxx. My K6 doesn't have one of those new fangled ISCs so I have no direct knowledge. But I'm thinking that you could experiment by seeing what happens if you crimp the air hose (it may not start when crimped, i.e. you may have to do this while it's running).

Haven't checked recently but you used to be able to buy an SDS system for around $150 on AliExpress. It will read the codes, as well as codes for faults that have been corrected, and allow you to manually control and reset the ISC.

Yoshimura sells parts that blank off the ISC and adjust the idle so that you set everything manually, like on the K6. See 764-508-1000 and 799-508-0000. But I don't know why they would be required.
Thanks for the help.

I have pinched off the hose while running and idle returns to normal. The engine can even be at operational temp (about 180*F) and it still draws air through. I'm fairly certain the valve isn't fully closing. Just not sure why.

The wire harness for the engine in the car does not have the connector for SDS tool unfortunately.

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I see two things in the K7/K8 service manual that may be relevant. Page 4-79 talks about a pre-set position and the importance of not disconnecting either the ISC or the ECM within five seconds of turning the ignition off. Page 5-26 talks about setting the ISC preset and the ISC learned value. Unfortunately they want you to use SDS to fix things. You might want to add the dealer mode connector and SDS. It provides a lot of information. I've previously posted here about SDS.

Don't know if this will fix things or make them worse but you might try disconnecting the ECM for five minutes. It's possible that the preset position is stored in volatile memory. I guess it's also possible that this is how you got to where you now are.
 

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Discussion Starter #5 (Edited)
I see two things in the K7/K8 service manual that may be relevant. Page 4-79 talks about a pre-set position and the importance of not disconnecting either the ISC or the ECM within five seconds of turning the ignition off. Page 5-26 talks about setting the ISC preset and the ISC learned value. Unfortunately they want you to use SDS to fix things. You might want to add the dealer mode connector and SDS. It provides a lot of information. I've previously posted here about SDS.

Don't know if this will fix things or make them worse but you might try disconnecting the ECM for five minutes. It's possible that the preset position is stored in volatile memory. I guess it's also possible that this is how you got to where you now are.
I was so wondering how hard it would be to use the SDS tool. Just need to figure out how get and wire in the SDS service connector

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I'd have to check but I think that only three lines from the ECM are used. They would be pins 62 (K-line), 36 (ground), and 12 (12 V).
 

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Thanks for the help.

I have pinched off the hose while running and idle returns to normal. The engine can even be at operational temp (about 180*F) and it still draws air through. I'm fairly certain the valve isn't fully closing. Just not sure why.

The wire harness for the engine in the car does not have the connector for SDS tool unfortunately.

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You could just plug the air hose and then adjust idle manually. No need to buy an SDS tool etc.
Don't raise the idle too high (close to 2000rpm) or it will trigger an FI code.
 

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Discussion Starter #8
You could just plug the air hose and then adjust idle manually. No need to buy an SDS tool etc.
I've had that in the back of mind, just plugging the inlet completely and leave it, but I wasnt sure what other effects this may have ...

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I've had that in the back of mind, just plugging the inlet completely and leave it, but I wasnt sure what other effects this may have ...

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Only effect is a cold start. You may need to keep throttle open for a while before engine is warm enough.
 

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The sense I get is that's what the Yoshimura parts do. 764-508-1000 replaces the hose with plugs at either end and 779-508-0000 is an extended length idle speed control with knob on the end. I think it's length is such that you can adjust the idle without raising the tank, etc. But I really don't know. No idea if it's appropriate for you.

P.S. Corrected the speed control pn above.
With regard to my initial question about the ECM pn, K7's had a recall involving the ISC where both the ISC and the ECM were replaced. Per Suzuki Bulletin #172, "Suzuki Motor Corporation has determined that all GSX-R1000K7 motorcycles are equipped with an Idle Speed Control (ISC) Valve that may not return to the correct start-up position each time the ignition switch is turned to the off position. Due to improper shape of the internal mechanism that moves the ISC valve, the valve may remain in the open position instead of moving to the correct start-up position. This can result in no-load engine idle speeds as high as 5000 RPM’s the next time the engine is started." In addition to the ISC, the ECM was replaced with 32920-21H60 or 32920-21H70. If you have 32920-21H10 or 32920-21H20, yours has not been replaced. The recall ISC is marked with a yellow dot on the top. There are reports here that a malfunctioning ISC will produce a buzzing.
 

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Just ditch the valve. Save weight, and basic useless parts. Just need a jumper wire under the seat. Closed loop once disconnected valve is sprung wide open. Been on a 750 done that way since 06. Did it to my 17 also. Live in N. ID AND STARTS JUST FINE IN FREEZING COLD.
 

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Just ditch the valve. Save weight, and basic useless parts. Just need a jumper wire under the seat. Closed loop once disconnected valve is sprung wide open. Been on a 750 done that way since 06. Did it to my 17 also. Live in N. ID AND STARTS JUST FINE IN FREEZING COLD.
You clearly have no idea what you are talking about. At least it doesn't have anything to do with OP's issue. ;)
 
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