Engine surging

[TownsendsFJR1300]

Any updates Tom?

 

[trepetti]

Bunch of maybes... More to the story. When I did the subframe painting, I removed my Power Commander Fuel Controller. With that, I reverted back to my stock 'Co' settings. But I fat-fingered the C2 entry, made it 0 instead of 6. Not positive of what the Cx settings do, but it seems pretty clear they add/remove fuel. So I made C2 (cylinders 2 & 3?) lean.

First ride after that was much better, but there is still some minor but noticeable surge. I bumped the Cx setting up by 2, thinking that my installation of the Dominator exhaust a few years ago could change the volumetric efficiency of the motor and lean things out. I didn't ride with this setting because the idle got smoky and rich smelling and didn't feel right.

The Ring Free is due today and I have a nearly full tank. Going to dump 10oz of the juice in and start there. With nearly 80k on the motor, the injectors MUST be at least a little wonky.

So in summary, the CO adjust minimized the issue to almost a non-issue, but with the Ring Free on the way, going to launch an attack the fuel system details.... And am going to check the TPS, but I don't think that is an issue....

Anyone ever send their injectors out for cleaning / calibration?

 

[Gary in NJ]

New injectors are ~$160 (ronayers.com)...and rebuilds go for a fraction of that cost (all 4 can be rebuilt for the cost of one replacement). While I haven't had to rebuild a FI, I wouldn't hesitate to have them rebuilt. At 80K miles or 6 billion cycles (5,000 rpm x 60 x 80,000 divided by 4) they may be a little tired.

 

[trepetti]

New injectors are ~$160 (ronayers.com)...and rebuilds go for a fraction of that cost (all 4 can be rebuilt for the cost of one replacement). While I haven't had to rebuild a FI, I wouldn't hesitate to have them rebuilt. At 80K miles or 6 billion cycles (5,000 rpm x 60 x 80,000 divided by 4) they may be a little tired.

Was thinking about looking for a used throttle body assembly and scarfing the injectors from there. Or waiting to the off-season and sending mine...

 

[trepetti]

Update - Added a shock treatment of Ringfree (10oz in a full tank) and put about 120 miles on it today. The problem is still there. I don't think that the RingFree is going to fix the issue, but I did notice better smoothness when picking up the throttle and in overall operation.

I am beginning to think that my problem might be related to a sensor. I am not positive, but the problem might be manifesting itself at certain throttle openings. Might point to the TPS.

Additionally, I don't know if the bike is getting 'warmed up'. Today was a mild day, maybe 70 degrees, and when riding the temperature display never gets more than 2 bars. If the ECU thinks the bike is cold it is going to adjust the mixture. If the temp is not consistent then the mixture might be in flux, swinging from rich to lean andvback again.

Anyway, just my thoughts as I continue to gather data.

FYI, I ordered a used throttle body assembly. The plan is to rebuild the idle air controller and perhaps send the injectors out for cleaning and calibration.

 

[Gary in NJ]

FYI, I ordered a used throttle body assembly. The plan is to rebuild the idle air controller and perhaps send the injectors out for cleaning and calibration.

You might want to check the operation of the coolant temperature sensor. If the sensor fails the ECU uses a fixed output of 60C (140F). This would support your "two-bars" reading. This should trip Fault Code 21...but if you are on the threshold of failure...maybe not yet. This type of failure will also keep the fan from turning on which could lead to an over temp.

To test the sensor, remove the sensor and place it into boiling water - WHILE KEEPING THE TERMINALS DRY. There is a temperatue/resistrance table on page 8-46 that you can check the output of the sensor as it cools from boiling to room temperature.

Note, when reinstalling the sensor the FSM suggests using 3-bond on the threads and tightening to 14 lb-ft

 

[trepetti]

Update - Not much to update....

I went out for am hour-long ride yesterday and the surging was pretty bad. Wondering if it is temperature related. Still lots of raw data that supports no conclusions....

Couple of things to report...
1 - Temp display still seems to be low. Yesterday was 85 degrees and never saw more than 3 bars on the LCD.
2 - Cold idle seems normal and it drops predictably to 1260-1320 when tach LCD stops blinking.
2a - The surging rarely shows up right away. Usually 10-15 minutes into a ride. When the surging starts, the idle seems to jump a bit higher to 1380 - 1440
3 - I cleaned the contacts on the Intake Air Temperature, the Intake Air Pressure and the Coolant Temp sensors. No particular reasons, but not long ago they were all disconnected when I serviced the starter.
4 - I tested the TPS and it meets the specs in the FSM.

Ideas / Next Steps
1 - Considering the problem is sporadic, I am thinking that if it IS a sensor, it is not a failure, but instead related to accuracy and consistency. Instead of removing and testing the 3 sensors (see above), each sensor has a fail-safe mode, where accuracy is ng but there should consistency. So performance might noticeably suffer, but there should not be any wild swings in ECU input (and therefore fueling). Thinking of unplugging 1 sensor at a time and test riding to see if anything measurable happens.
2 - I want to make sure that the cold engine temperature is an instrumentation issue, not a genuine issue. I need to make sure that there is a dramatic temperature change in the upper radiator home when the thermostat opens.
3 - When I removed the throttle bodies a few weeks ago, I essentially touched EVERYTHING that might cause a vacuum leak. Although the symptoms are not really consistent with a leak, I need to revisit that and double check.
4 - I received the eBay throttle bodies and have removed the injectors to send down to 'Injector RX' in Houston TX for cleaning and reconditioning. They seem to be a reputable outfit, and charge $18.00/injector. If anyone has any first-hand experience with them or another shop, let me know.

Anyway, just wanted to bring everyone up to speed and to share my ideas and spark some thoughts. Let me know your thoughts.

Thanks

 

[Gary in NJ]

Did you happen to conduct a vacuum leak test with a (unflamed) propane torch? It is the most accurate way - and easiest way - to test for leaks.

I would also suggest a leak-down compression check.

 

[trepetti]

Update - Not much to update....

I went out for am hour-long ride yesterday and the surging was pretty bad. Wondering if it is temperature related. Still lots of raw data that supports no conclusions....

Couple of things to report...
1 - Temp display still seems to be low. Yesterday was 85 degrees and never saw more than 3 bars on the LCD.
2 - Cold idle seems normal and it drops predictably to 1260-1320 when tach LCD stops blinking.
2a - The surging rarely shows up right away. Usually 10-15 minutes into a ride. When the surging starts, the idle seems to jump a bit higher to 1380 - 1440
3 - I cleaned the contacts on the Intake Air Temperature, the Intake Air Pressure and the Coolant Temp sensors. No particular reasons, but not long ago they were all disconnected when I serviced the starter.
4 - I tested the TPS and it meets the specs in the FSM.

Ideas / Next Steps
1 - Considering the problem is sporadic, I am thinking that if it IS a sensor, it is not a failure, but instead related to accuracy and consistency. Instead of removing and testing the 3 sensors (see above), each sensor has a fail-safe mode, where accuracy is ng but there should consistency. So performance might noticeably suffer, but there should not be any wild swings in ECU input (and therefore fueling). Thinking of unplugging 1 sensor at a time and test riding to see if anything measurable happens.
2 - I want to make sure that the cold engine temperature is an instrumentation issue, not a genuine issue. I need to make sure that there is a dramatic temperature change in the upper radiator home when the thermostat opens.
3 - When I removed the throttle bodies a few weeks ago, I essentially touched EVERYTHING that might cause a vacuum leak. Although the symptoms are not really consistent with a leak, I need to revisit that and double check.
4 - I received the eBay throttle bodies and have removed the injectors to send down to 'Injector RX' in Houston TX for cleaning and reconditioning. They seem to be a reputable outfit, and charge $18.00/injector. If anyone has any first-hand experience with them or another shop, let me know.

Anyway, just wanted to bring everyone up to speed and to share my ideas and spark some thoughts. Let me know your thoughts.

Thanks

I think I got it. I went ahead with the 'uplugging the sensors' test, starting with the coolant temp sensor. My thinking was that of the 3 suspects, the coolant temperature sensor lives the hardest life.

So before making any changes, went out for a control ride to make sure the problem was still there and to pay close attention to the onset of the surging so that I had some datapoints to compare. Same problem. Strarts off ok, but after 10 ish minutes the surging starts and the idle speed becomes less stable. And the good news was that is was a bad ride. It would not be hard to tell if any of the changes impacted the problem.

I came home and let the bike cool down a little, then I unplugged the coolant temp sensor. Problem solved....gone..over...just like that. Rode for over an hour to make sure I gave the bike ample time to malfunction, Nothing, nada, zip, zilch.

The only misdiagnosis risk I see is if a functional sensor could trigger a down-stream problem with another component. But the only other component is the ECU.

Just ordered an Amazon replacement part for delivery tomorrow as an $11.00 proof of concept. If everything works well I MIGHT give in to my OCD and order a genuine Yamaha part. Probably not. If things DON't work well, I'll be back with my tail between my legs......

Additional question. Yamaha mentions 'Threebond Sealock 10' on the threads. Must have been popular in 2005 when the manual was published. No longer in the Threebond product line. Anyone know a suitable substitute? I am going to take a guess and order a different Threebond product to start, but it looks like an easy sensor to reach if I need to take it out and apply a different product.


Wish me luck......

 

[Gary in NJ]

I believe Threebond 1184 will work in that application. Check the product data sheet.

 

[trepetti]

I believe Threebond 1184 will work in that application. Check the product data sheet.

Thanks Gary. I ordered Permatex 59214 because it would arrive in the same Amazon box.... specs say good to 400F. Waiting for parts today.

 

[trepetti]

Thanks Amazon. When you list something as 'delivered tomorrow', I interpret that as "Today's" tomorrow, not tomorrow 2 days from today.

New delivery date for the sensor is tomorrow. That's tomorrow from TODAY.

 

[TownsendsFJR1300]

Thanks Amazon. When you list something as 'delivered tomorrow', I interpret that as "Today's" tomorrow, not tomorrow 2 days from today.

New delivery date for the sensor is tomorrow. That's tomorrow from TODAY.

They've been doing that ALOT lately. And shipping completely wrong items or damaged...

 

[trepetti]

Learned something new tonight.

After my test rides on Saturday where I kinda confirmed it was the coolant temp sensor, I noticed that some of my connectors looked a little grungy, so I figured it was a good time to get out the contact cleaner and dielectric grease. Cleaned things up and plugged everything back in and I was getting a strong crank but no start. Scratched my head and reinspected everything but same result. Went to diag mode and see the coolant temp registering -30. Manual says that if the coolant temp sensor fails, the ECU sets the temp to 60c. Plugged the sensor back in and it started right up.

When I did my test on Saturday, the bike was still warm from my control ride. Started right up after unplugging the sensor. I even stopped for gas and restarted no problem. Tonight the bike was stone cold and would not start.

So it looks like an FYI....cold bike, no coolant temp sensor, no start.

 

[trepetti]

They've been doing that ALOT lately. And shipping completely wrong items or damaged...

I only hope I get the right part. I was reading some of the reviews and there was one that said the fit was too tight. I am not easily swayed by reviews, but I am big on having a plan b. I ordered an OEM sensor from Partzilla last night just in case.

 

[Motogiro]

Learned something new tonight.

After my test rides on Saturday where I kinda confirmed it was the coolant temp sensor, I noticed that some of my connectors looked a little grungy, so I figured it was a good time to get out the contact cleaner and dielectric grease. Cleaned things up and plugged everything back in and I was getting a strong crank but no start. Scratched my head and reinspected everything but same result. Went to diag mode and see the coolant temp registering -30. Manual says that if the coolant temp sensor fails, the ECU sets the temp to 60c. Plugged the sensor back in and it started right up.

When I did my test on Saturday, the bike was still warm from my control ride. Started right up after unplugging the sensor. I even stopped for gas and restarted no problem. Tonight the bike was stone cold and would not start.

So it looks like an FYI....cold bike, no coolant temp sensor, no start.

Interesting! This is very important to know.....

 

[trepetti]

...and the score after 2 periods is Amazon 2, Tom 0.

Got the part last evening and it has the wrong connector. Its connector is more squared-off than the OEM. Looks like I could force the connectors together, but not for a cheap Chinese-made replacement. My 'plan-B' OEM part is with UPS and scheduled to be here tomorrow......

 

[trepetti]

New sensor (OEM) was delivered yesterday. Had a chance to install it and do an errand.... 30 minutes out and 30 minutes back. Problem solved. Finally saw 4 bars on the temp gauge when stopped at a long light.

So remember that if your coolant temperature sensor misbehaves, you might have a big, 'bucking problem!

 

[trepetti]

Did you happen to conduct a vacuum leak test with a (unflamed) propane torch? It is the most accurate way - and easiest way - to test for leaks.

I would also suggest a leak-down compression check.

Hey @Gary in NJ, the propane vacuum test sounds interesting. It sounds pretty straight forward, but it also sounds like the kind of process that will punish you if you do it wrong.

Can you elaborate on the safe way to do this without ending up in a 'Darwin Awards' video

 

[Gary in NJ]

It’s as simple as it sounds

1. Start the engine and allow it to idle. If the bike has a vacuum leak it may not idle so you may need a helper to adjust the throttle or you can adjust to idle screw.

2. Open the propane torch all the way without lighting it. Move the tip of the torch around suspected/likely places of a vacuum leak; carb/TB boots and any linkages that move through the carb/TB. If the rpm’s increase or the idle suddenly becomes smooth, you have found the source of the leak. No change = no leak.

The reason this works is because the vacuum leak will ingest the propane (fuel) instead of just air, temporarily making the air:fuel ratio richer.

If the torch does come in contact with a spark…it will simply light the torch. Propane can pool, so I would limit the activity to 60 seconds at a time. On a four cylinder bike it takes about 30 seconds to get the left two cylinders done and the same for the right…so the fear of pooling is limited.