Throttle Delay

[rocketman]

I have an 07, when the engine is braking, decelerating and producing a high vacuum in the intake, there is a time delay when going back on throttle. Your off throttle, the engine is braking, you open the throttle back up and NOTHING, then your throttle is 1/4 open the vacuum goes down and the bike jerks and lurches forward. I am wondering if the intake pressure sensor is programmed to turn off the ignition and or fuel injection in high vacuum situations to prevent backfiring or popping or some other situation. It makes it very hard to get a smooth shift when the throttle does not come back on the same position every time. My geuss is they would not shut off the ignition but only the fuel injection.

Do any other FJRs have this problem or is it only the 07's.

How do I remedy it?

Yamaha repair or service update?

Power commander?

Disconnect sensor?

Updated ECU from an 08?

Reprogram the ECU and sensor values?

 

[ionbeam]

Try beginning with this.

 

[Solo]

Much has been written here on this topic. IMHO (and many would agree with me) the one full remedy is a Power Commander, PCIII, non-ex version.

 

[radman]

I assume the cable slack is adjusted correctly?

 

[rocketman]

Thanks, sounds like the power commaner worked for everyone who did it. Looks like my easiest way out.

 

[wfooshee]

Fuel shutoff or at least very lean mixture on over-run is very common in electronic fuel injection systems, for both economy and emissions. Cars, with their higher inertia, are not as sensitive to on/off/on transitions.

As stated, a PCIII will cure it. I run the Wally Smoothness on my '03, and somewhere there's a version modified for the GenII bikes like yours.

 

[rocketman]

I remove the intake pressure sensor from the throttle body manifold, so its always open to ambient pressure (for the atmospheric measurement). Left the wires on the sensor. Sealed the manifold back up.

Went for a 35 mile ride.

Eliminated almost all of the throttle delay when engine is braking and shifting (high vacuum).

A lot smoother.

Seems a less jerky when riding slow with no load on the engine.

Idle seems lower.

Check engine light stays on.

I've got to ride it a lot more. Find out the pluses and minuses in performance. See if I can make it work properly.

If not it's PCIII.