Air Cooled EFI Triumph Surging/Bogging

[MaksTO]

I've touched on this in previous posts, but after a bunch more research am still coming up pretty empty handed so looking to start a dedicated thread to troubleshoot.

This doesn't seem to be related to the tune or pipe, as I've read of this issue on various bike configurations.

Basically in low/mid RPM range the bike feels off as it warms up and once it's at temp. Noticeable jumps in power between 2500 and 3000/3500 ish RPM, kind of feels like your going over bumps or something (someone on another forum put it this way, and it's the most accurate way I've found to describe it). When downshifting in this range, the bike will sometimes bog quite badly as well. Up in higher revs the bike seems to run fine, but maybe there's just more inertia with the speed that makes this less noticeable.

At consistent throttle at those RPMs you can almost hear the pipes being starved of fuel, but it's quite subtle. I've had plugs changed, my air filter looks good, MAP hoses and sensors were tested at a shop, and so I am continuing on my search.

A recent discussion with an aftermarket Triumph parts shop in the UK led me on a new theory - fuel pump failure. They told me this isn't an unheard of issue in their experience. Though I've read of others speculating online about this, I haven't read anywhere of replacing the pump being a fix either. This has been ongoing on and off (mostly on) for the last year since I've had the bike. Not sure if a fuel pump can partially work like this for so long. One theory I read was failing pump bearing causing cavitation or introducing air bubbles that can lead to this - again, I've no idea if this is even possible.

I'd happily pull apart the fueling system and replace everything, but costs for these parts are quite high (about $500 after pump, fuel filter, and gasket... if pressure regulator too then more like $600).

I'm kind of at a loss at this point. I can still ride the bike mostly fine, but in the city it's incredibly annoying. On highways and longer distance trips I generally don't go slow enough for this to be an impediment to my riding.

Would greatly appreciate anyone's expertise!

 

[GreyGhost]

Fuel pump weakness is normally felt first at high load and high rpm (eg max demand).

Have you tried shoving a wide band O2 up the pipe? Then at least you'd have some numbers to work with. If it is going rich and bogging, that is unlikely to be the fuel pump and could be a spark problem.

 

[MaksTO]

Fuel pump weakness is normally felt first at high load and high rpm (eg max demand).

Have you tried shoving a wide band O2 up the pipe? Then at least you'd have some numbers to work with. If it is going rich and bogging, that is unlikely to be the fuel pump and could be a spark problem.

I don't have a wide band O2 unfortunately. Where would be the best place to get one? Seems prices vary pretty wildly online, so not sure what to look for.

I'm also wondering if maybe some of the fuel hoses inside the tank may be cracking and that may cause problems?

Edit: I've seen others online replace the ignitors and cables for spark plugs with no results. Obviously their problem may not be the same as mine, but I'm trying to at least use others experiences as a ballpark for now. I gotta figure out how to test those parts maybe and take a multimeter to them.

 

[GreyGhost]

I don't have a wide band O2 unfortunately. Where would be the best place to get one? Seems prices vary pretty wildly online, so not sure what to look for.

I'm also wondering if maybe some of the fuel hoses inside the tank may be cracking and that may cause problems?

Edit: I've seen others online replace the ignitors and cables for spark plugs with no results. Obviously their problem may not be the same as mine, but I'm trying to at least use others experiences as a ballpark for now. I gotta figure out how to test those parts maybe and take a multimeter to them.

Some are better than others. On the upside, you are mainly looking for differences in A/F ratio than caring about absolute numbers so most would work for you. The mini has an Innovate as that was the best available at the time. I have a spare AEM in the garage that I plan to setup for temporary use. I haven't got around to it yet.

 

[bitzz]

If you think your problem is fuel pump related, you want to monitor your fuel pressure (there is a spec in the service manual).
Try putting a multi meter across the MAP to see if that jumps around (you probably won't find a spec for the MAP but monitor it to see if it's voltage is going up and down when it should)
There are O2 "kits" available, AIM comes to mind, but I just knock in a bung (available at any auto parts store for a couple of bucks. Be sure to get the plug.) and use a Bosch O2 sensor and a multi meter. When it goes above 7.5v you're rich, below 7.5v and you're lean
... or you could throw parts at it.

 

[GreyGhost]

If you think your problem is fuel pump related, you want to monitor your fuel pressure (there is a spec in the service manual).
Try putting a multi meter across the MAP to see if that jumps around (you probably won't find a spec for the MAP but monitor it to see if it's voltage is going up and down when it should)
There are O2 "kits" available, AIM comes to mind, but I just knock in a bung (available at any auto parts store for a couple of bucks. Be sure to get the plug.) and use a Bosch O2 sensor and a multi meter. When it goes above 7.5v you're rich, below 7.5v and you're lean
... or you could throw parts at it.

Interesting. What type of sensor are you using? Are you running a heater? For unheated, the bung is probably required as the end of the muffler won't be hot enough.

 

[MaksTO]

If you think your problem is fuel pump related, you want to monitor your fuel pressure (there is a spec in the service manual).
Try putting a multi meter across the MAP to see if that jumps around (you probably won't find a spec for the MAP but monitor it to see if it's voltage is going up and down when it should)
There are O2 "kits" available, AIM comes to mind, but I just knock in a bung (available at any auto parts store for a couple of bucks. Be sure to get the plug.) and use a Bosch O2 sensor and a multi meter. When it goes above 7.5v you're rich, below 7.5v and you're lean
... or you could throw parts at it.

I've got bungs on the pipes already thankfully (O2 sensors are off the bike so they're available to use), so just need sensors.

Might see if any local shops have them to test first. But I guess either way I have to throw money at the problem in one way or another.

Have to figure out how to measure the MAP sensor as well as fuel pump pressure. Hopefully manual outlines it... Will take it home today and do some reading.

 

[GreyGhost]

I've got bungs on the pipes already thankfully (O2 sensors are off the bike so they're available to use), so just need sensors.

Might see if any local shops have them to test first. But I guess either way I have to throw money at the problem in one way or another.

Have to figure out how to measure the MAP sensor as well as fuel pump pressure. Hopefully manual outlines it... Will take it home today and do some reading.

Wait a minute. What's been done to this bike? Did it come stock with 02 sensors and that has been removed? Did aftermarket pipes come with bungs just in case? Which tune? Did you ask tuner about the issue?

 

[MaksTO]

Wait a minute. What's been done to this bike? Did it come stock with 02 sensors and that has been removed? Did aftermarket pipes come with bungs just in case? Which tune? Did you ask tuner about the issue?

Bike has an Arrow 2-1 (it was actually an aftermarket pipe that Triumph sold as an option from factory / it was green lit by them).

O2 sensors on this bike are only only for open loop operation at Idle for emissions, and from what I've read have no effect when riding above something like 5% throttle, I have a tune that's widely been regarded as the best for this setup.

I've spoken to the person who wrote the fuel map and researched it generally, and in nearly all cases it's shown to be substantially better than OEM which (supposedly) runs very lean. There's an Arrow specific Map that Triumph uploaded with the pipe from factory, but the local Triumph dealer has no clue about it and have no ability to install it, so I am SOL there. Mine was installed on the bike by a third party by previous owner, hence why I went through this in the first place as I wanted to make sure it was running the proper ratio. So much for that!

When speaking to the Tuner they told me to inspect the Map Sensors and vacuum hoses, which I had a dealer do since I wasn't sure how to go about it. They said everything with the system is functioning normally. It's the TTP Tune #2 (Triumph Twin Power tune for Air Cooled EFI Scramblers).

I was also wondering if the issue could be from gunk in the injectors or something along the way, as I remember having this issue last summer, and after adjusting the Throttle Position Sensor (which I also confirmed was within spec very recently), the issue went away - only to rear it's head again this spring. It's weird. Some days it's better than others, but seems to be getting a little worse lately. Really hard to tell what's going on. Was going to pick up some injector cleaner at the end of the week and run it through a tank to see if it changes anything.

I've also heard of TPS sensors failing or being on the fritz, but again I am currently just speculating at possible causes. There seem to be so many possible things that I am really having a hard time building a game plan on what to start with. I need to make a list

Times like this I wish I was back on a carburetor LOL.

 

[GreyGhost]

I would definitely be spending money/time on diagnostic tools not the parts cannon. It sounds like there are many possible systems that could have issues. Make a list and start crossing them off. Ideally tracking tests done and outcomes. Don't just write passed, write down while accelerating hard in third gear from 2000 rpm to redline, fuel pressure varied from x to y, no noticeable dips. Then when people ask you what you tried, you don't need to do it again. A well placed camera that can see gauge and tach is far safer than looking at the gauge while accelerating. That also gives you poverty data logging that can be reviewed later.

 

[MaksTO]

I would definitely be spending money/time on diagnostic tools not the parts cannon. It sounds like there are many possible systems that could have issues. Make a list and start crossing them off. Ideally tracking tests done and outcomes. Don't just write passed, write down while accelerating hard in third gear from 2000 rpm to redline, fuel pressure varied from x to y, no noticeable dips. Then when people ask you what you tried, you don't need to do it again. A well placed camera that can see gauge and tach is far safer than looking at the gauge while accelerating. That also gives you poverty data logging that can be reviewed later.

Are there sensors that I can attach to all of these systems while riding the bike? Where would I go about looking for these?

Maybe I'll have to pony up for an Android Tablet and see if TuneECU has the ability to monitor and record these things while riding. That would be ideal honestly.

 

[GreyGhost]

Are there sensors that I can attach to all of these systems while riding the bike? Where would I go about looking for these?

Maybe I'll have to pony up for an Android Tablet and see if TuneECU has the ability to monitor and record these things while riding. That would be ideal honestly.

I have an older android tablet you can have. Screen has a crack but it works fine.

 

[bitzz]

Are there sensors that I can attach to all of these systems while riding the bike?

A multi meter, maybe two or three multi meters.
The MAP outputs a range from 0v to 5v (0 volts is a defective sensor, unless you're working on an old Dodge)
o2: over 7.5v is rich, below 7.5v is lean.
Take RPM off the switched side of the coil
What other sensors are you looking at? Have you looked at the temp sensors?

 

[PacoT]

If I understand correctly, this might be similar to a common issue for the Tridents and Tigers 660s.

At low rpms and barely pulling the throttle, it feels like you were constantly closing and opening the throttle.

A couple of weeks ago, Triumph issued a recall for the 660s. Maybe check if your bike also has a recall.

 

[MaksTO]

A multi meter, maybe two or three multi meters.
The MAP outputs a range from 0v to 5v (0 volts is a defective sensor, unless you're working on an old Dodge)
o2: over 7.5v is rich, below 7.5v is lean.
Take RPM off the switched side of the coil
What other sensors are you looking at? Have you looked at the temp sensors?

I'm just flipping through the manual now to gauge what they suggest to troubleshoot. It's a laundry list about a page long but it covers what I have below and then a pile more.

Personally, I've read that the following things could cause these issues:
- Bad Ignitors
- Map Sensor, or the vacuum hoses going to it (supposedly these are all operating fine according to a shop after diagnostics)
- Crank Position Sensor
- Throttle Position Sensor
- Fuel Pump, or Fuel Filter, or Fuel Pressure Regulator
- Gummed up Injectors

To test if it's a fueling issue, I might change the air box cover to the snorkel and see if that has any effect. Tthough my tune specifically asks for an open bellmouth, which I currently have installed.

I'm also planning to try some Lucas injector cleaner in the tank to see if it's an injector clogging issue.

Fuel filter is overdue for replacement so I may do that over the winter, and inspect the pump to see if it's functioning normally.

As for the electrical stuff, I'll have to take it one at a time. I have a multimeter, just have to figure out where to probe without damaging the wires or anything else on the bike. I haven't actually done multimeter testing before so this is totally new to me.

If I can get TuneECU to run, I may also try to install the factory Triumph Arrow 2-1 tune and reinstall the O2 sensors in order to see if that improves the riding condition. Though I'm doubtful of it given the reputability of my existing tune (supposedly.. Again I'm sort of in the dark on EFI things and going off of hours of research exclusively).

 

[MaksTO]

If I understand correctly, this might be similar to a common issue for the Tridents and Tigers 660s.

At low rpms and barely pulling the throttle, it feels like you were constantly closing and opening the throttle.

A couple of weeks ago, Triumph issued a recall for the 660s. Maybe check if your bike also has a recall.

View attachment 62963

I just looked up my VIN on the Triumph site. No dice for me unfortunately (or fortunately?)

Thanks for the tip though! Was definitely worth a check, and this sounds very similar to my issue, so I'm inclined to still not rule it out despite being told this system is functioning normally.

 

[bitzz]

Personally, I've read that the following things could cause these issues:
- Bad Ignitors
- Map Sensor, or the vacuum hoses going to it (supposedly these are all operating fine according to a shop after diagnostics)
- Crank Position Sensor
- Throttle Position Sensor
- Fuel Pump, or Fuel Filter, or Fuel Pressure Regulator
- Gummed up Injectors

Ignitors is sorta a generic term, we need more information
Map sensor is a variable resistor, use a meter to read output
Crank position sensor is a hallmark sensor, so is the cam position sensor
Throttle position sensor is a variable resistor
Test fuel pump/system pressure by plumbing a pressure gauge into the system (there are ports)
Take the injectors to an injector shop for inspection, they NEED specialized equipment to diagnose

I, personally have ZERO faith in a mail order ECU map... no, even less than zero. I have never seen one work as advertised. The FIRST thing I would have done was remap the thing back to stock. What does the guy that wrote the map you're using say about this?

 

[MaksTO]

Ignitors is sorta a generic term, we need more information
Map sensor is a variable resistor, use a meter to read output
Crank position sensor is a hallmark sensor, so is the cam position sensor
Throttle position sensor is a variable resistor
Test fuel pump/system pressure by plumbing a pressure gauge into the system (there are ports)
Take the injectors to an injector shop for inspection, they NEED specialized equipment to diagnose

I, personally have ZERO faith in a mail order ECU map... no, even less than zero. I have never seen one work as advertised. The FIRST thing I would have done was remap the thing back to stock. What does the guy that wrote the map you're using say about this?

Once I get TuneECU going, I'll try to install the Triumph OEM tune for this specific exhaust and reattach the O2 sensors to see if that solves anything. I believe it's Map 20514 according to TuneECU. Maybe that's what I will start with, since that would at least give me an OEM baseline for how this was supposed to run from factory. Minus the Air Injection System which I have no desire to put back on, though it shouldn't have an effect on any of this.

The guy who wrote the map suggested looking at the MAP sensor and Vacuum hoses, as those are apparently first points of failure on these bikes as they begin to age. Thing is he is retired as of a few months ago, so I think getting in touch for more troubleshooting help is unlikely.

Part of me wonders if it's because we have different fuel here. I think these tunes are all for 0 ethanol fuel, and I imagine since everything moved to E10 here, it could maybe lead to issues? Triumph for this reason has a tune for both E10, and E25 for this exact pipe.

If this fails, then I will have to proceed to the other things which will be more labor intensive.

 

[MaksTO]

One more interesting update. I don't know why I didn't pay attention to this sooner.

So the Arrow 2-1 Midpipe and Silencer are held on with those spring hook things that I always see on snowmobiles and dirt bikes. From what I've read, Arrow doesn't instruct to install sealant when mating the three pieces together, and most people generally don't use sealant on these connections.

However: I inspected the midpipe and silencer sections when cold starting, and noticed a big draft from each of them, which I suspect may be complicating my diagnostics - if not being the problem altogether. I've attached photos below of the two connection points. You can see vast soot buildup - that's where the exhaust blows through.

Would this be cause for some of the issues I'm describing? Surging, backfiring, popping etc? I know at the header popping is always a main sympton, and sometimes bogging and surging, but not sure if its the same story further down the pipe.

FWIW I have the ultra-copper high temp permatex at home that I've used to repack exhausts before. Should that be adequate?

 

[GreyGhost]

One more interesting update. I don't know why I didn't pay attention to this sooner.

So the Arrow 2-1 Midpipe and Silencer are held on with those spring hook things that I always see on snowmobiles and dirt bikes. From what I've read, Arrow doesn't instruct to install sealant when mating the three pieces together, and most people generally don't use sealant on these connections.

However: I inspected the midpipe and silencer sections when cold starting, and noticed a big draft from each of them, which I suspect may be complicating my diagnostics - if not being the problem altogether. I've attached photos below of the two connection points. You can see vast soot buildup - that's where the exhaust blows through.

Would this be cause for some of the issues I'm describing? Surging, backfiring, popping etc? I know at the header popping is always a main sympton, and sometimes bogging and surging, but not sure if its the same story further down the pipe.

FWIW I have the ultra-copper high temp permatex at home that I've used to repack exhausts before. Should that be adequate?View attachment 62984View attachment 62985

I doubt that would cause the symptoms as not much gas is coming out there. On an old honda I had to use packing rings to seal that gap. It doesn't look like you have enough room to get a ring in. I have no idea about using permatex there. If I did use it, I would be inclined to take exhaust apart and lay a bead deep in the female that the male would then press into. Won't be a disgusting mess on visible pipes. I would be quite concerned about temp for the permatex though. It tops out at 700 or 750. At the end of the header, you could be well beyond that (wouldn't be surprised with very low four digit gas temps when you are beating on it) and spraying hot copper goo all over your bike.

It would probably mess up wideband readings at the end of the muffler. Those gaps could draw fresh air in between pulses.