PC5 Surge

I've been lurking around the forum for years, then finally bought a 2012 FJR, with 2800 miles on it, about 10 months ago. I thought I had learned what most of the quirks were and what the remedies were, during my lurking. I was wrong.

The bike had no surging problems when I got it. It started to develop the 3k surge, at the 2-5% throttle range, at around 5500 miles. By 6500 miles the surge moved to a wider rpm range and started to annoy me. I bit the bullet and got the Power Commander 5 installed, with the O2 sensor disconnected. This made it about 75% better. I figured that I could improve a little more with some map tuning, but was content for the time.

By 7500 miles the surge was getting worse. I tried a few maps, provided by guys here, several more around the web and numerous tweaks of my own. At one point I even added up to 20% more fuel in the problem areas, with no help. I installed the switch where I could swap between two maps on the fly. For a while I left the zero map in one position and a modified map in the other. The modified map always made a big difference over the zero, so it was better but not great.

By 8000 miles it progressively got worse, to the point that it ran VERY poorly on the zero map. Time for a TBS. I just knew this would fix it. Wrong again, sync was nearly perfect. I think i adjusted #2 TB about 1/16 of a turn.

At 8200 miles I ran a good concentration of Seafoam through a tank. Put new plugs in and cleaned the air filter. Old plugs and filter looked fine. During this session I checked all of the vacuum lines, electrical connections (including battery terminals) and anything else I could think of.

At 8400 miles and pulling out what hair is left.

By the way, at 10% throttle or more it runs perfect.

What am I missing?

Why would this progressively worse?

Is it time for the unofficial TBS?

Any ideas?

I've learned a lot around here and hope to learn more.

Thanks in advance.

Perhaps a faulty TPS sensor..?!

A pity you can't burrow a LCD200 to view and data log what may be going on.

And with an Autotune you can set the actual A:F ratio you wish.

it's surprising but it's not all about dumping fuel in, it's surprising where the Autotune leans off the fuel for a particular RPM / TPS - A:F ratio.

I finally convinced Mr Yamaha here in Australia that I had a crook ECU, aka the high altitude surge problem on my 07.

It wasn't a recall in Australia.

I've read on the forum about a crook TPS that got worse as the heat from the motor increased.

Also you could check the connector block on the ECU for corrosion and re-seat it a few times.

Try the UnAuthorized TBS. Can't hurt and it might help.

Click the little NERD down there for the full procedure

V

V

I considered the TPS, but since the problem is not specific to a single throttle position (it's over the 0-10% range) it didn't spend much time looking at it. I will hook a meter up and look at the sweep though.

Fred - Thanks for the link to the UA TBS. That is one of the better write-ups I've seen on the subject.

That is basically the procedure I use on my other bikes with carbs. It seems to me that Yamaha has the sync procedure backwards anyway. Since the bypass air adjustments have little effect on flow, past idle, it wouldn't make sense for this to affect much at 4000 rpm. It would make sense to (re)align the moving mechanical parts that are cycled thousands and thousands of times and are expected to stay in perfect alignment with each other.

I will try the UA sync and see what happens.

Thanks for all of the input so far.

While a UA Synch might make something of an improvement, I can't imagine that it will cure your issue. From your description, your bike is almost unrideable at lower throttle settings. I would start back at square one. Pull the Power Commander and repeat the conventional TBS. While the PC may smooth things out a bit, it doesn't make THAT much difference. I suspect it may be masking whatever the real problem might be. The PC is not a fix for a bike with problems in the ignition (coils/wires/plugs), TPS, fuel delivery, air delivery, electrical connections or ECU.

Have you checked fuel pressure? Seems like you may have a failing fuel pump...

Thanks for all of the suggestions. The UA synch made MAJOR improvements. They were not very far out of sync, but I spent quiet awhile trying to get them near perfect. By the time I finished the whole process, the idle was noticeably smoother. Since my problem slowly got worse over time, the one thing I had not noticed was how buzzy the bike had gotten. On my test ride, by the time I got into 3rd gear, it felt like I was riding a different bike. The buzz and vibration was gone.

I won't say that I got rid of all of the surge, but I no longer hear the roughness or light stumble in the exhaust that was there at light throttle. I might be able to tweak the PC maps a little more to tune it out completely.

Thanks for the help.

Update...OK, maybe I'm just too picky. I can't tune (mask) the rest of the surge condition out of the bike. I went back and tried one of the other UA sync methods just for kicks, like syncing at 3000 rpm. On my bike it doesn't seem possible to have perfect syncronization at 1000 AND at 3000 rpm. The middle cylinders either read a little higher or lower vacuum (don't remember now), when synced at idle and then held at 3000 rpm. This is actually where they read before I ever touched them. It seems I'm just moving the surge range around. It does seem that I've narrowed it some. The problem area is now between 2500-3000 only. Above and below is smooth.

The bike is far from unrideable. In fact a few friends had to ride it for several miles to see what I'm talking about. There again, maybe I'm too picky. I ride the little YZF600R 250 miles a week to work and it has spoiled me and made me more critical of the FJR. At 60 mph (4900 rpm) it's like an electric motor....smooth. My fuel injected bike may never duplicate this.

The TPS sweep on an analog meter is perfect with no bobbles. I've set it from the low end of the range to the high end and in between. The IAP sensor checks out. I've rechecked the electrical connections throughout. Fuel pressure is good. I'm fairly confident it's a fuel/air flow or balance problem.

I'm not new to FI tuning. I spent many years retrofitting late model fuel injected engines in old classic vehicles and 4x4s. Spent many hours burning custom chips and data logging for these projects. The difference was I had tools to look at manifold pressure, injector pulse, timing, rpm, O2 and many other functions in real time. Not so much here.

I guess I just wanted to vent a little. I'll keep tinkering with it. I have a 2000 mile ride coming up in a couple weeks and I'm trying to get it as good as it's going to get.

Shooting in the dark here, but have you removed the PAIR system? I suspect at least some of the FJR's throttle problems originate with dirty throttle plates, and imo they get cruddy with blowback from the PAIR system. When I replaced the PAIR with WynPro plates, I noted that the PAIR reed valves were coated with sticky residue.

BTW, I have one of those LCD 200 things, and when I'm finished using it I'd be happy to loan/rent it out to other forum members who wish to fine-tune their PC-V units.

I have a different question for you. What is your idle speed set at? Is it set at the FJR forum recommended 1100 rpm? We bumped our idle up to 1000 while our PC-V was on order but had not arrived. We almost wished we had not spent the money on the PC-V. Almost.

silver spirit said:

Shooting in the dark here, but have you removed the PAIR system? I suspect at least some of the FJR's throttle problems originate with dirty throttle plates, and imo they get cruddy with blowback from the PAIR system. When I replaced the PAIR with WynPro plates, I noted that the PAIR reed valves were coated with sticky residue.
BTW, I have one of those LCD 200 things, and when I'm finished using it I'd be happy to loan/rent it out to other forum members who wish to fine-tune their PC-V units.

Click to expand...

I haven't removed the PAIR system yet, but sounds like I need to. I may need to get a closer look at the throttle plates. Thanks.

Redfish Hunter said:

I have a different question for you. What is your idle speed set at? Is it set at the FJR forum recommended 1100 rpm? We bumped our idle up to 1000 while our PC-V was on order but had not arrived. We almost wished we had not spent the money on the PC-V. Almost.

Click to expand...

Sitting at 1100. Thanks.

Another thing that puzzles me is that you say your problem is getting worse with more miles. That does not describe the surging issue that we normally deal with on the Gen 2. That issue is there from day one and continues with no change. It also surprises me that you are having this issue with the 2012. Most of the lean fueling issues were taken care of after '07. The later year models I rode still had a slight surge at low rpm but nothing like the '06 and '07.

I am at a loss as to why the problem would worsen with age and mileage.

Redfish Hunter said:

Another thing that puzzles me is that you say your problem is getting worse with more miles. That does not describe the surging issue that we normally deal with on the Gen 2. That issue is there from day one and continues with no change. It also surprises me that you are having this issue with the 2012. Most of the lean fueling issues were taken care of after '07. The later year models I rode still had a slight surge at low rpm but nothing like the '06 and '07.
I am at a loss as to why the problem would worsen with age and mileage.

Click to expand...

+1

That's why I'm thinking dirty throttle plates could be somehow involved. It also occurs to me it could be misfiring/dirty injector(s).

A gradual (negative) change in performance is unlikely to be electrical, so I'd be looking at all the air/fuel system components.

I hooked the sync tool back up today to recheck everything and in my problem area (2500-3000 rpm), the vacuum reading is dead nutz even on all 4 cylinders. The strange thing is, even with perfect sync, there is still a bump in the exhaust tone. Not a dead miss, but not smooth. This is what I'm feeling and hearing when cruising in this range.

The bike has always had a little valve train tick, but running it with the tank off the bike, the valve train noise was more noticeable. It is concentrated on #1 or #2 cylinder. Obviously the tick tracks the rpm, but there is additional valve train noise that occasionally cycles in and out with no particular pattern, starting at about 2500 rpm. Hmm that is where my problems start. Maybe I should start looking for mechanical problems. Not something you'd expect at 9000 miles. It's not "time" for a valve check.

Valve to tight or too loose? I'm a pushrod engine guy. Not much experience with overhead cams...yet.

Excuse my ignorance, but when you describe the surge, are you talking about the abrupt feeling of on/off with the throttle from full off? On my 07, the best way that I can explain it is to compare it to trigger pull weight with a gun. My friend's 04 always seemed to be very smooth when applying throttle when reaccelerating from throttle off. Mine however, seems to be a more discernable on/off. Basically as I apply pressure to reapply throttle, I actually feel a "break" when I go from off to on. By that time I feel that I have over applied pressure and am concerned about over throttling, especially in curves.

This year, we balanced the throttle bodies and that seemed to improve the responsiveness slightly. Or maybe I am just used to it and have learned to ride through it. Not sure.

When I go to shops, I always grab the throttle of other bikes between my index finger and thumb and see if I can twist the throttle. Always can. But on my bike, it is very difficult to do.

Any ideas? Not a deal breaker for me but something that has bothered me from day one.

wantucce said:

Excuse my ignorance, but when you describe the surge, are you talking about the abrupt feeling of on/off with the throttle from full off? On my 07, the best way that I can explain it is to compare it to trigger pull weight with a gun. My friend's 04 always seemed to be very smooth when applying throttle when reaccelerating from throttle off. Mine however, seems to be a more discernable on/off. Basically as I apply pressure to reapply throttle, I actually feel a "break" when I go from off to on. By that time I feel that I have over applied pressure and am concerned about over throttling, especially in curves.This year, we balanced the throttle bodies and that seemed to improve the responsiveness slightly. Or maybe I am just used to it and have learned to ride through it. Not sure.

When I go to shops, I always grab the throttle of other bikes between my index finger and thumb and see if I can twist the throttle. Always can. But on my bike, it is very difficult to do.

Any ideas? Not a deal breaker for me but something that has bothered me from day one.

Click to expand...

Throttle spring unwind? Stiff throttle hasn't been an issue on my '11, but iirc it was on some earlier Gen IIs. Search the forum for throttle spring unwind, throttle snatch etc..

This post is not really a continuation of my previous post titled "PC5 Didn’t Fix the Surge", but how I eliminated 97% of the surge, without adjusting CO settings or using custom maps in the Power Commander. (Disclaimer: The PC is hooked up running the straight through or zero map with the O2 sensor disconnected) I wanted to share some of the lessons learned on my bike, that may or may not help you if you’re fighting the problem. Over the past 6 months and 7000 miles I was determined to get it to stop surging or I would get rid of it. Most of the details up to this point are in my other post.

Since I’ve had the sync tool hooked up more than 20 times in the last 6 months, I start with the most valuable lessons. IF you decide to do the Un-Authorized TBS, like the well written one by Fred W, I do recommend capping off the Air Injection system (during sync), as Fred had done previously. A few times I didn’t do this and the results were not good. Mine is now removed. The biggest find, during all of my fine tuning was, with all of the back and forth tweaking of the sync screws, they all ended up turned in (CW) about 1/8 of a turn from the factory setting. The throttle bodies were perfectly balanced and the TPS still read in the range that was considered closed throttle (16), but all of the throttle blades were open too far from their true home position. Obviously this contributes an even more lean condition than the lean factory programming creates. Before I discovered this, I found that you can throw enough fuel at it, with the PC, to mask some of the problem, but it created a very abrupt throttle.

Some symptoms of this are:

1. Takes longer to start. I had to hold the starter button in longer and spin it more than previously.
2. The bike will idle fine at 1000 rpm with the air bypass screws completely closed off.
3. Engine running hotter than normal. Possibly to the point that the exhaust will start to glow, while tuning.

I could still see the factory marks well enough, on the sync screws, to put them back in the original position, but I went about an 1/8 of turn CCW from the original setting, thus closing the blades a little more. I synced everything again, being careful to not adjust in the direction that would open the blades anymore. It actually took very little adjusting to get the balance.

Originally all of my bypass screws were set at about 7/8 of a turn out. This time I started at about half a turn out and fine tuned the balance from there. The idle speed settled in at about 1100 rpm.

I realize that all this does is slightly reduce the air flow and balance everything at this position, but can it be that simple? Very minor adjustments can make a big difference. The bike runs better than it ever has, starts as soon as you touch the button, doesn’t smell rich and made it very difficult get into any position where it would surge. I wished I’d figured this out before I went on a 1500 mile trip last week.

It has been reported that the air bypass screws have little effect on air flow, once you get past idle. On my bike this is not at all true. To prove this, briefly hold your rpm at 2500 rpm or so and make a small adjustment and watch the sync gauge run out of the range on top or bottom. This being the case, running these screws in a little and bumping the idle up may help a minor surge some, in the dreaded 2000-3000 range.

One more lesson learned: The Intake Air Sensor has a long body and plug, and the way it’s mounted and where it’s located, makes it easy to break. If leaning over the bike and you happen to put your hand on the plug for support, you will have lots of leverage to break the plastic body. They are kinda pricey

Sorry for the long post, but if it helps anyone it’s worth it. I would have paid lots of money, and still had more hair, to have learned this sooner. Several shops told me they couldn’t help me and said that is just the nature of the bike. Unacceptable. With proper diagnostic tools it could have been identified sooner, but you got to work with what you got.

Kc5 said:

It has been reported that the air bypass screws have little effect on air flow, once you get past idle. On my bike this is not at all true. To prove this, briefly hold your rpm at 2500 rpm or so and make a small adjustment and watch the sync gauge run out of the range on top or bottom. This being the case, running these screws in a little and bumping the idle up may help a minor surge some, in the dreaded 2000-3000 range.

Click to expand...

I'm not sure that actually proves that. With rpm at only 2000-3000 on an essentially freewheeling (unloaded) engine the throttle butterflies will still only be open a small amount, probably on the range of less than 5% of total throttle. So naturally at that small throttle opening the air bypass screws would still be contributing a relatively significant amount of the total intake air at that point. When you are riding down the road at cruising speeds, and the engine is fighting the wind to maintain headway, the throttle will be open quite a bit more. The more the throttle is open the less significant the bypass air will be.

On a second gen the idle speed adjustment doesn't vary the throttle cable stop position (like it does on 1st gens). Instead it is another, additional air bypass to raise or lower the idle speed. (edit: I see now that it feeds all 4 throttle bodies) So the setting of that idle adjuster may be responsible for some of the confusion that occurs on 2nd gens during throttle balancing.

One more note: The "dreaded" lean surging isn't in the 2000-3000 rpm range. Most FJR riders never even spend any time below 3000 rpms. On my first gen bike, without the PC3 enrichment of the fueling, I get the dreaded surging at any constant rpm, not just below 3000.

In any case, glad you worked out your problem.