Odd idle RPM's

[Sikorsky]

So after 3 months of mucking about, I have have the beastie back together and started up.

 

Over the winter I've installed one of Prez's cruise controls, did a cat removal and installed the OEM Honda grips. The previous season had a reflash done on the ECU and a Power Commander with custom map in case this has any effect on what I just observed. Also, the battery is 1 season old and fully charged. 

 

First of all, the bike hasn't been test driven so these observations were done with it on the bench. The green "power on" light for the cruise works, so far so good. Road test to follow.

 

The weird part occurs when the heated grips get switched on, idle RPM jumps from 1100 RPM to 3000-3100 RPM and sometimes as high as 4500 RPM. Second temp level on the grips lowers the RPM to 2200-2300 RPM which stays the same when switched to the lowest temperature. Grips off, RPM drops to regular idle. 

 

Normal? Any input is welcome.

[Grum]

On 2 April 2018 at 3:32 AM, Sikorsky said:

So after 3 months of mucking about, I have have the beastie back together and started up.

 

Over the winter I've installed one of Prez's cruise controls, did a cat removal and installed the OEM Honda grips. The previous season had a reflash done on the ECU and a Power Commander with custom map in case this has any effect on what I just observed. Also, the battery is 1 season old and fully charged. 

 

First of all, the bike hasn't been test driven so these observations were done with it on the bench. The green "power on" light for the cruise works, so far so good. Road test to follow.

 

The weird part occurs when the heated grips get switched on, idle RPM jumps from 1100 RPM to 3000-3100 RPM and sometimes as high as 4500 RPM. Second temp level on the grips lowers the RPM to 2200-2300 RPM which stays the same when switched to the lowest temperature. Grips off, RPM drops to regular idle. 

 

Normal? Any input is welcome.

Hi Sikorsky.

Your problem sounds very strange! So your saying this problem has only occurred since fitting the Heated Grips, Cruise Control and removing the Catlytic Converter. So I assume the bike was running fine last season after fitting the PC?

 

So in removing the Cat what has happened to the two Oxygen Sensors?

 

Is there any chance the wiring to the Heated Grips is having a nasty effect on the PC? Verify you've wired both PC, Heated Grips power correctly.

 

Can you easily bypass or disconnect the PC to get back to normal ECM function to see if this has an effect?

 

Just throwing a couple of ideas at you. Don't have the VFR1200 and know Jack Shite about a PC.

Good Luck and maybe some of the 1200 experts may be able to chip in.

Cheers.

 

[Darrenk]

No experience with any of your mods, but I imagine an increase in RPMs as the demand on the alternator goes up would be normal, but I don't think such a drastic increase is normal...I agree with Grum; check the wiring of the heated grips.

[BiKenG]

First of all, when you get a problem after fitting several things, you just have to remove them, one at a time (or remove them all and fit them again, one at a time) to ascertain exactly which item is causing the problem. Having said that, it could be a combination of more than one item causing the trouble, but it is unlikely you have 2 faulty devices so would come down to how they've been installed and connected..

 

I have experienced a fast idle problem with a 1200f which turned out to be a problem with the 'Ride-By-Wire' throttle stepper motor drive gears sticking (probably unlikely for you unless the bike's been under water), however it did show up a few surprises, like the ECU raises the rpm when in gear and you let out the clutch. This is now common on Hondas (helps take off apparently) and normally not noticeable, but if any other problem is raising the rpm, this can become very noticeable. Have you somehow wired the grips to the clutch switch circuit that is causing the ECU to think the clutch is being engaged/disengaged. Just to be clear on this, the ECU DOES monitor the status of the clutch. Is your bike DCT? In that case, I've no idea. 🤔

 

However, the most likely culprit here is the Cruise Control. This device is intercepting the Throttle Control Position Sensor output and sending its own signal to the ECU, so the ECU is controlling engine speed based on what the CC is telling it and since this is all voltage based, is it possible you have the grips wired to those same circuits which is distorting the voltage seen on those sensor connections to the ECU?

 

As far as I can recall, the grips have their own connection available in the wiring loom and shouldn't need any other connections, but without knowing how it's all been installed, it's impossible to know. Have a good look at how you have connected these additions to be sure it has all been done correctly.

 

Disconnect all items that have recently been installed (i.e. since it was running correctly). Re-connect them individually and see if they cause any problem on their own. Then re-connect them together and see if the problem returns. I'm afraid it's a bit of trial and error to try and ascertain what's causing the problem.

 

Actually, I'd start by disconnecting the CC so the throttle control is back to standard and see the result. That should give you a good idea of what's going on.