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1Back to top Go down   Extreme idle +4000 RPM Empty Extreme idle +4000 RPM Sat Aug 06, 2022 6:46 am

StefanMolzen

StefanMolzen
active member
active member
Hi all

I just made a rebuild of a K100 to Cafe racer.
Added a M unit blue and new controls and speedometer.
Removed original Airfilter box, and mounted Airflow meter directly to inlet. 
Added a Lunch Box remover unit from Joost.

It started immediately. But running insane high RPM. Around 4000+ can't measure it, since I need to shut it down fast.

I have looked at my wiring, and can't see any error. 

The bike ran ok before I took it apart, but with broken breather hoses etc. So not in good condition, and not sure what previous owner has done.

The wires are replaced to M-unit (light, instruments, buttons etc), but for FICU and ignition it is the original. 

I have tried to:
- bypass the Throttle Butterfly Switch with 12V to the white/black wire, to simulate idle. No change.
- Disconnect the Air Flow meter, then it won't start at all.
- Check that I have +12V at the Throttle Butterfly Switch, ok. 
- Check for clearance in the gas cable. Ok.
- Checked resistance in water temp. sensor. Seems a bit low, around 1,9 K-Ohm, but should this increase RPM to 4000+ ?
- Checked for mechanical air leak. 

The Fuel Injection Control Unit is getting RPM information from Ignition Trigger Assembles, as far as I can see in the diagram. This connection is the original. So I don't think the FICU sees a wrong RPM, or am I missing something ?

Checked the hose connections from tank to rail and Fuel pressure regulator, seems correct. 

The vacuum switch is still there, but wires disconnected. Will this cause this issue ?

Is there any electrical issue, that can cause the FICU to increase the RPM so much ?

    

2Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 9:33 am

Laitch

Laitch
Life time member
Life time member
Have you completely disconnected the throttle cable from the throttle body assembly then started the engine?


__________________________________________________
1995 K75 81,000 miles
Extreme idle +4000 RPM Usa-lo10
    

3Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 9:36 am

StefanMolzen

StefanMolzen
active member
active member
Yes just did, no change. Still extreme idle

    

4Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 9:43 am

StefanMolzen

StefanMolzen
active member
active member
Laitch wrote:Have you completely disconnected the throttle cable from the throttle body assembly then started the engine?
Yes, same issue.
Measured all connections between airflowmeter, ecu and ignition unit. All ok.

    

5Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 10:44 am

Laitch

Laitch
Life time member
Life time member
Have you viewed the position of the valves within the throttle bodies with an inspection mirror?


__________________________________________________
1995 K75 81,000 miles
Extreme idle +4000 RPM Usa-lo10
    

6Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 1:08 pm

StefanMolzen

StefanMolzen
active member
active member
Laitch wrote:Have you viewed the position of the valves within the throttle bodies with an inspection mirror?
Problem solved. Mechanical block of throttle, so not going all way back to idle mode. Thank you 😊

    

7Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 2:17 pm

Laitch

Laitch
Life time member
Life time member
That's good news, Stefan! Can you be specific about what was interfering? A lot of us are just sitting in the shade today waiting for excitement like this to inspire us.


__________________________________________________
1995 K75 81,000 miles
Extreme idle +4000 RPM Usa-lo10
    

8Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sat Aug 06, 2022 3:28 pm

StefanMolzen

StefanMolzen
active member
active member
Laitch wrote:That's good news, Stefan! Can you be specific about what was interfering? A lot of us are just sitting in the shade today waiting for excitement like this to inspire us.
 🤣 yes sure, one of the belts holding the rubber inlet needed to be turned a couple of centimetres, to allow the throttle fall back to idle position. So small fix to a big headache 😀

    

9Back to top Go down   Extreme idle +4000 RPM Empty Re: Extreme idle +4000 RPM Sun Aug 07, 2022 6:32 am

bad boy

bad boy
Silver member
Silver member
right Stefan
you've already found the reason
the hose clamp just above the inlet can get in the way preveting the butterflies to close all the way


__________________________________________________
Cheerz, David

Extreme idle +4000 RPM 9438-010

____________________________________________________________________________
1997 Peraves Super Ecomobile: a Kevlar reinforced monocoque with outrigger wheels, seating two.
K100 fork, monolever, headlight, indicators, K1100RS gearbox and K1200RS 589 engine, rear wheel
    

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