Gen 3 surging

[wheatonFJR]

Update?

Yeah, when you get home from your 1700 mile weekend today, give us an update. Take a shower first though.

[1911]

I didn’t see any surging going on

[Festus]

It's time for an update! Don't get excited, it's not fixed.

Viper Dad reached out to Intech and setup a time to check the valves. We did that yesterday. All valves in spec. Crap. I had convinced myself it was surging because of a valve being way out. Wasn't the case.

Once back together, Bob started it and was holding the throttle dead still at 2,000 rpm and it just took off, running up to 3,000 RPM, if I remember correctly. Then it could come back down, go back up. He tried again. Same thing. Had Viper Dad hold the throttle. Same thing. I filmed the throttle linkage and while it was surging, nothing was moving. I put my fingers on the throttle cables at the linkage and nothing was moving. I held the throttle. Same thing.

Okay, now we're getting somewhere. Dead still throttle and it's revving up 1,000 rpm's and coming back down and going back up.

What would cause an engine to run faster? More fuel/air. How's it get more fuel? Fuel injectors. What tells the fuel injectors to send more fuel? ECU.

I looked at the schematic and the coil packs and fuel injectors go directly to the ECU. So is the throttle map corrupt or is one of the sensors sending the signal to the ECU that it needs more fuel? Hummmm..... not sure how to diagnose that one. Is it firing because the map is wrong or because it's getting an improper signal from something else?

What else could it be? Intake Air sensor? Maybe telling the ECU that it needs more fuel? Since mice ate the wiring up when we got her, maybe there's a bad wire somewhere that we never saw?

My thought was to start pulling the connectors at the sensors and at the ECU and checking the resistance in each wire, hoping to find an issue.

On the right track?

Of course, we have the simple fix of swapping my ECU with his, which we can do. I suppose that's the easiest way to eliminate whether it's a corrupt fuel map file. If swapping the ECU's doesn't fix it, then it almost has to be the intake air sensor or a bad wire? (thinking out loud here)

[FJRoss]

ECU swap maybe but I would be surprised.
Still possible throttle position sensor - did you try swapping between the bikes? Replacement could be bad.
Also, there is the accelerator sensor associated with throttle bodies...
Have you monitored fuel pressure variation?
Did you have injectors cleaned/tested - can't remember if you swapped them between bikes.

[Festus]

Haven't swapped the TPS between bikes but did check the diagnostics for the one on it and it was good but he replaced it anyway and it read good in the diagnostics as well.

He also replaced the accelerator sensor with a new one. Nothing changed.

He put a new fuel pump on, we swapped fuel injectors and coil packs, as well as tanks. No changes. I did clean the injectors but also swapped them, nothing changed.

That's what makes me wonder if it's a bad wire somewhere. But I also think a bad wire would show up in the diagnostics but maybe not. I don't know enough about what it's reading or if a compromised wire (some strands cut) would change that.

Also swapped out the Fuel Pump Relay with the one on Bob's bike. Same results, nothing changed.

[Festus]

In the schematics, I see a "Throttle Servo Motor". Any chance it's that?

[FJRoss]

In the schematics, I see a "Throttle Servo Motor". Any chance it's that?

The throttle servo motor is what actually moves the throttle cables. You said you couldn't feel them moving...
Note: I would use a throttle lock as opposed to having someone hold the throttle steady at a certain rpm. An imperceptible movement could make a significant difference.

I think I would still try the TPS swap.
Might as well rule out the ECU too.

[LKLD]

At the very least, it appears that you’re getting closer to diagnosing the problem. I hope you find the solution.

[blind squirrel]

Note: I would use a throttle lock as opposed to having someone hold the throttle steady at a certain rpm. An imperceptible movement could make a significant difference.

Damn Bob! He's calling you out!!

[raYzerman]

I am skeptical of there being a corrupt fuel map file, but likely more of a sensor input causing the issue..... given you've replaced/fixed most of what it could be, a swap of ECU's will rule that out.

There are two MAP (Intake Air Pressure) sensors on a Gen3... one open to atmosphere and one connected to vacuum. Oddly enough, same on my old 1999 VFR... I tested it OK but I still had to replace it to fix my error code issue....... you can test the voltages, and confirm that the vacuum line is not obstructed in any way. I'd still think you'd have other running/idling issues if bad.....

Now that you made me look into this more, I'm wondering just what that servo motor on the TB's does.... if there is one shaft right through the TB's, ie, move the throttle cables and butterflies move, that would also include the TPS and the APS..... but what is the servo doing? And I do not know. One thing we do know is it must do something when you first let out the clutch a bit to start off from a stop..... engine speed increases by 100 or so rpm without any throttle input...

But, if you're holding the throttle steady and it surges, then the servo motor may be doing something. How would it move the TB shaft if you're holding the throttle cables is the question....... have to take a set of these apart someday..... there's nothing in the FSM except to replace the TB's as a complete unit.

One thing I'd do is go into DiAG and reset the Idle Speed Control learning condition to zero, even if it already displays 00. I remember somebody doing this to solve a problem he had, but don't know if I can find that again.......

[Dan Cooper]

Pardon me if I jump in here uninvited and add my .02 cents worth. Keep in mind I haven't re-read this thread from the beginning lately so if this has already been covered, my apologies for repeating.

On the GEN 3 FJRs the throttle is fly-by-wire.
The throttle cables from the handlebar are not connected directly to the throttle bodies.
The throttle cables are connected to the Accelerator Position Sensor.
The Accelerator Position Sensor is not connected directly to the throttle shaft.
The Accelerator Position Sensor tells the ECU how far the driver has turned the throttle (what you want the engine to deliver).
The ECU tells the Throttle Servo (stepper) Motor how far to turn the throttle shaft, opening the butterflies (what the ECU says you can have under control of the ECU fuel and spark maps and sensor inputs, etc.).
This also turns the Throttle Position Sensor which is attached to the end of the throttle shaft.
The Throttle Position Sensor feeds back to the ECU telling how far the butterflies were actually opened by the Servo Motor.
It's a continuous dance that moves to a 1000 times a second beat.

The Throttle Servo Motor turning the throttle shaft will never have any effect on the throttle cables from the handlebar to the Accelerator Position Sensor.

All of the system sensors provide input to the ECU for fuel and spark control, including the Accelerator Position Sensor, Throttle Position Sensor, MAP sensors, air temperature sensors, engine (water) temperature sensors, etc., and the Oxygen Sensor which plays a part in steady state throttle position and engine speeds.

As discussed in other threads previously the Oxygen Sensor in this system is not particularly sophisticated. It is sensing for oxygen in the exhaust flow. Too much oxygen in the exhaust, it tells the ECU to supply more fuel. Too little oxygen in the exhaust, it tells the ECU to reduce fuel.
But it is like a Papa Bear / Mama Bear situation, it only senses too much or too little oxygen, it never senses Baby Bear just right oxygen levels and tells the ECU "Steady as She Goes" !!

So my .02 worth (since you've already tried every damn thing else short of nuclear options) is the possibility of a faulty Oxygen sensor or wiring causing the ECU to cycle fueling up and down in too wide swings at steady state throttle settings. In acceleration / deceleration situations the Oxygen Sensor inputs are not considered by the ECU.

I suppose there is the possibility of a faulty Throttle Servo Motor, but that item is not separately serviceable. The only way to test for that is swap complete throttle body assemblies. Actually, I think there is a way to test the Throttle Servo Motor in the diagnostics. But I don't know if that test might be the same thing as testing the TPS showing good when it isn't.

The Throttle Position Sensor is relatively easy to adjust / change, the Accelerator Position Sensor adjustment / replacement requires removing the throttle bodies from the engine.

I'm not an engineer, test pilot, or maintenance specialist and I didn't spend the night behind the dumpster at a Holiday Inn Express. So take these suggestions with however many grains of salt you may wish, preferably with a Margarita, or two.


dan

[Festus]

Great info guys, something I'm going to need to read several more times and digest. I think you might be onto it Dan.

The issue I was stuck at was trying to figure out if the ECU was acting up or if they ECU is just reacting to something feeding it bad data (most likely). We've never talked or looked at the Oxygen sensors as a possibility.

Thanks for replying.

[FJRoss]

Great info guys, something I'm going to need to read several more times and digest. I think you might be onto it Dan.

The issue I was stuck at was trying to figure out if the ECU was acting up or if they ECU is just reacting to something feeding it bad data (most likely). We've never talked or looked at the Oxygen sensors as a possibility.

Thanks for replying.

Try running with the O2 sensor unplugged...
You will do better with no input than a faulty and variable input.

[raYzerman]

We should have asked, are there any error codes in DiAG??

I believe on Gen3, an unplugged O2 sensor will trigger a code, however, try it and see if the problem is cured.
Another sensor to check is the Cylinder Identification Sensor.... however, if unplugged, bike won't start.

[Viper_Dad]

We should have asked, are there any error codes in DiAG??

I believe on Gen3, an unplugged O2 sensor will trigger a code, however, try it and see if the problem is cured.
Another sensor to check is the Cylinder Identification Sensor.... however, if unplugged, bike won't start.

Thank you everyone for your input. Since I don't make it on here much, Festus has been keeping me updated on your suggestions. Ray - how does one check for codes in the diagnostic menu? And thanks to those who have spent their time and brainpower to help me work through this. After 25K+ miles Jolene is a member of my family so I'm not about to put her out to pasture!

[FJRPittsburgh]

I found this while searching online:

Generation 3 diagnostic function and ES (AE Australian ) error code 44
Aka stepper motor reset

Thought I'd share my post for those interested
This procedure will not work on the new Generation 4's, ya basically buggered..... dealer time

Let me know how you go, I'll edit this post. Can't walk to the bike at the moment.

NOTE:
Error codes and diagnostic code are different, don't use those words loosely.
On the ES aka AE, have your suspension set as solo rider, if possible.

1: Accessing the diagnostics, error codes.

Place your FJR on the centre stand, in neutral, side stand up. This will let you test the side stand switch.

With the ignition off and the Engine Run switch off, press and hold the "TCS" and "Reset" buttons together simultaneously and turn the ignition on, just ON, continue to hold the buttons until the display.

The first screen will be the ECU / SCU ( Suspension Control Unit) display.

Press "TCS" to increment the diAG sequence number and press "Reset" to decrement the diAG sequence number


For example:
The two digits at the bottom of the ECU display is the value for the diagnostic code number.
Diagnostic Code dI:01 lets you look at the throttle position sensor, TPS output, same on all the generations.
The TPS value is the two digits at the bottom of the display. Turning the actual throttle slowly will change the bottom two digits.

Normal is 15-17 with the throttle fully closed and 97 to 100 with the throttle fully opened.

.
2: Access error code 44

Toggle via the "TCS" up or "Reset" down buttons to access the SCU screen, press and hold both “TCS” and Reset” once again simultaneously to gain the SCU diagnostics.



3: Reset the stepper motors

The bike must be on the centre stand and battery fully charged, engine switch in the off position.

Go to diagnostic code 84,
Press and hold both “TCS” and Reset” once again simultaneously to start the stepper calibration.

Multiple attempts will bring up another error.

Wait 5 minutes before you do anything else, then turn off ignition and see what happens.


4: Reset error codes

Go to diagnostic code 62 and press “TCS” and Reset” once again simultaneously for 2 seconds.
No error codes on diagnostic 61 or diagnostic 62 should remain.Generation 3 diagnostic function and ES (AE Australian ) error code 44
Aka stepper motor reset

Thought I'd share my post for those interested
This procedure will not work on the new Generation 4's, ya basically buggered..... dealer time

Let me know how you go, I'll edit this post. Can't walk to the bike at the moment.

NOTE:
Error codes and diagnostic code are different, don't use those words loosely.
On the ES aka AE, have your suspension set as solo rider, if possible.

1: Accessing the diagnostics, error codes.

Place your FJR on the centre stand, in neutral, side stand up. This will let you test the side stand switch.

With the ignition off and the Engine Run switch off, press and hold the "TCS" and "Reset" buttons together simultaneously and turn the ignition on, just ON, continue to hold the buttons until the display.

The first screen will be the ECU / SCU ( Suspension Control Unit) display.

Press "TCS" to increment the diAG sequence number and press "Reset" to decrement the diAG sequence number


For example:
The two digits at the bottom of the ECU display is the value for the diagnostic code number.
Diagnostic Code dI:01 lets you look at the throttle position sensor, TPS output, same on all the generations.
The TPS value is the two digits at the bottom of the display. Turning the actual throttle slowly will change the bottom two digits.

Normal is 15-17 with the throttle fully closed and 97 to 100 with the throttle fully opened.

.
2: Access error code 44

Toggle via the "TCS" up or "Reset" down buttons to access the SCU screen, press and hold both “TCS” and Reset” once again simultaneously to gain the SCU diagnostics.



3: Reset the stepper motors

The bike must be on the centre stand and battery fully charged, engine switch in the off position.

Go to diagnostic code 84,
Press and hold both “TCS” and Reset” once again simultaneously to start the stepper calibration.

Multiple attempts will bring up another error.

Wait 5 minutes before you do anything else, then turn off ignition and see what happens.


4: Reset error codes

Go to diagnostic code 62 and press “TCS” and Reset” once again simultaneously for 2 seconds.
No error codes on diagnostic 61 or diagnostic 62 should remain.

[raYzerman]

Ignition off, kill switch off, sidestand down..... press and hold Select and Reset buttons, then turn on ignition. Continue to hold both buttons for 8 seconds... right hand display will change, then press and hold both buttons again for two seconds. Diagnostics should appear.... scroll through them with either Select or Reset.... when you get to d:61, if no codes it displays 00. If codes, it will display the number then automatically scroll through them so you can write them down.....
To clear all codes, go to d:62 and cycle the kill switch on and off. Done. To exit, turn off ignition.

Refer to service manual for extensive list....... post up what you find here.......

Jeff's post is mostly describing how to reset the electronic suspension..... you don't have.

[FJRPittsburgh]

Jeff's post is mostly describing how to reset the electronic suspension..... you don't have.

Well, I tried.

[Viper_Dad]

Jeff: stick to telling stories, you're good at that. Ray - Sounds easy, I'll try it tonight!

[FJRPittsburgh]

Jeff: stick to telling stories, you're good at that. Ray - Sounds easy, I'll try it tonight!

Did I ever tell you the story about how to access the diagnostics on a 2013?