First of all, great choice of motorcycle. That's the right color. I applaud your good taste

We had precisely the same issues with my dad's identical 2012 Bonneville SE (even the same color, and same color as mine). The root cause was rust in the tank due to disuse. The issue was clogged fuel filter and bad fuel pressure regulator. It was eventually fixed by cleaning the tank with vinegar (twice!) and replacing the fuel pump, fuel filter (twice!) and fuel pressure regulator. My advice is if you look into the tank and see any rust, just bite the bullet and do the whole job.

Other things it could be, assuming you didn't screw up the map, is a bad ignition coil or plug wires. I'm sure Ripper will be by in a minute to point out a half dozen other things. FYI my dad replaced the coils on his bike and the plug wires along with the plugs during the diagnostic time trying to work this out.

This issue seems to be coming up a lot on these decade old low-mileage bikes. The low mileage is the key. It was not frequently used so likely has rust in the tank.

 

The folks and posts that I have seen on this forum have been helpful so far! Thanks! I'm hoping for a little nudge on an issue I have.

In early June I bought my first Triumph, a 2012 Bonneville SE. Turns out it hadn't been ridden much for the past few years, and it has under 4,000 miles on it. It ran well enough during the test ride and has (until a couple days ago) been absolutely fine on the highway. I was really impressed with how smooth and powerful it was.

It has had some trouble idling and snatchy throttle, though. I have been running seafoam through it to see if it improves, and it did not. Maybe 150 or so miles of riding. I went for a few 40ish mile rides to try to see if it worked itself out.

Before I knew anything about the EFI systems on these bikes or had done any troubleshooting on the issue I suspected a TPS problem. I ended up getting a TuneECU rig to check it out. First reading was at .66 volts, so my hunch was to adjust it, Reset Adaptions following the process on the tuneecu site, and see how it went. TPS seems to move through the range as expected and reported by tuneecu.

The bike will not start and idle with the choke lever at any position now, for any length of time without the throttle. It has backfired and popped, and the couple times it has started the throttle does not rev the engine consistently and can't hold a consistent RPM without surging or dying. TuneECU reports that the bike is running map 20743. I didn't have any plans to change that. I'm amazed that it's worse. It was never able to get past the "Star the engine with the cold start knob pulled out and don't touch the throttle" step in the process below.

• Reset Adaption specifically for the Triumph EFI Twin models (Air-cooled models
  with cold start button):
• This procedure should be carried out with a cold engine.
• Connect device to your bikes ECM with your OBD2 USB cable.
• Turn the ignition on, wait 10 seconds and then turn it off again.
• Turn the ignition on and wait until TuneECU has connected, in the menu "Tests & Adjustments select
  "Adjustment" ------- "Reset Adaption".
• Once clicked you will get a "Reset Adaption Complete" message after 5-15 seconds, OK this.
• Start the engine with the cold start knob pulled out and don't touch the throttle.
• Let the engine idle for 15 - 30 seconds and push the cold start knob in, but only to the first indent and not all the way.
• After about 3-5 minutes or sooner if you think your engine will idle OK without you touching the throttle, push in the cold start knob all the way.
• Let the engine idle until the TPS light in the status bar becomes green, usually around 10 to 20 minutes.
• If the TPS light doesn't turn green after twenty minutes, don't worry and turn the engine off anyway as sometimes it doesn't trigger, and in our experience the job is done anyway.
• Turn the ignition off for a couple of minutes to ensure the ECM can save the adaptive data.

I did double check the idle knob position, and have reset it based on some of the advice on the forum. It is just at the point where it has slightly moved the throttle bodies plus a half turn. I checked the MAP sensor tubes and they look fine. I haven't pulled the plugs or fuel filter or any of that yet. I didn't want to start throwing parts at it until I had some sort of breakthrough. In the short time I've been able to keep it running the MAP sensors showed a reading of about 400, and they were equal.

I suspected the battery last night when I was working on it, and even though it turns the engine over quickly, it only reads 12.3v even after being on a battery tender for 24 hours. I think it's too low. I have a new battery on the way, but I doubt that is the only problem. It was at about 11.7v during all of the tuneecu and troubleshooting last night.

Any advice on where I should look next?

Any other Triumph heads in Minnesota / Minneapolis? I need to get over the hump of this issue to get back to loving the new ride!

Thanks!

12.3 volts is 70% charged so I don't think that has anything to do with your running issue. More likely a fuel issue

 

Do you guys believe a fuel pressure test should be next? A pump or filter issue should cause low pressure?

 

Sure, you can do a fuel pressure test. We did. But it's not a trivial test. You have to pull the tank and make up a hose with a T in it and have a fuel pressure gauge with the right fittings, figure out how to hotwire the fuel pump, etc. IMHO, just drain the gas, pull the tank, take the bottom plate out and then you'll go "OMG SO MUCH RUST" and then replace all the rusted up junk and clean the tank. It's like 50% more work than doing the fuel pressure test, and instead of spending money on hoses and fuel pressure gauge, put that money towards the $100 worth of fuel filter, fuel pump and pressure regulator.

 

Ok last question before I go about these recommendations.

The bike was very rideable and would idle on choke up until the exact time I readjusted the TPS and Reset Adaption using TuneECU. How does that relate to the tank rust issue? I cannot get it to run since that change. What gives?

 

Usually when I do something that causes a problem I back out, undo what I did. Try undoing your work.

 

I did for the idle knob and TPS but I don’t believe that’s possible for the Reset Adaptions.

 

Well, technically the Reset Adaptions just clears some memory, and the process of letting it idle until it is up to temp is in order to let the ECU re-learn and reprogram what you cleared. I agree that it's entirely possible you inadvertently broke something when adjusting the TPS. What's the specified range for the TPS voltage? Was 0.66v out of spec?

To re-diagnose the original "problem"... you say it initially had "trouble idling", right? So-called "snatchy throttle" is caused by the switchover from closed loop to open loop. But depending on what you mean by "trouble idling", it sounds to me like you have just progressed the original problem. Given the problem is at idle before and after your changes, my guess is it's actually an air leak somewhere. At idle, there's very little fuel so just a small amount of extra air can make it extremely lean. Your TPS adjustment may have made it worse by actually reducing the fuel at the idle throttle opening.

I still think investigation of potential rusty tank is warranted in a bike this age that has not been used regularly. But given your original problem, I think I would begin with a roll of new silicone vacuum hose and re-running all of the vacuum lines, including and most importantly the MAP sensor sections. While you're doing it, you can check the intake boots for cracks and in general inspect everything. Look, you have a motorcycle with less than 400 miles a year of average usage. Odds are anything that can degrade has degraded. Including rust in the tank and all of the rubber parts that have to be sealed.

 

Tonight I replaced the fuel filter and cleaned the pick up screen. It was much harder to blow air through the old fuel filter than the new. Not a very scientific test.

I replaced the spark plugs while I had the tank off. I inspected the MAP sensor vacuum lines but did not see any issue there or with the intake boots.

I installed the new battery I got with a full charge. Read 12.9v. It barely turned the bike over and started to just click on about the second attempt to start. I’m pretty sure I got a bad one. It was down to reading 12.2v within a minute.

I re installed the old battery that had been on a tender all day. It turned over fine and did fire with the choke knob out but the behavior has basically not changed. I can’t get it to run for more than a few seconds. Not at all with the choke knob in.

I’m not sure next which direction to head in troubleshooting.

the tank is a little rusty but not enough to immediately affect it with fresh gas.

 

Tonight I replaced the fuel filter and cleaned the pick up screen. It was much harder to blow air through the old fuel filter than the new. Not a very scientific test.

I replaced the spark plugs while I had the tank off. I inspected the MAP sensor vacuum lines but did not see any issue there or with the intake boots.

I installed the new battery I got with a full charge. Read 12.9v. It barely turned the bike over and started to just click on about the second attempt to start. I’m pretty sure I got a bad one. It was down to reading 12.2v within a minute.

I re installed the old battery that had been on a tender all day. It turned over fine and did fire with the choke knob out but the behavior has basically not changed. I can’t get it to run for more than a few seconds. Not at all with the choke knob in.

I’m not sure next which direction to head in troubleshooting.

the tank is a little rusty but not enough to immediately affect it with fresh gas.

Your battery sounds very suspect with the low voltage and dropping down to 12.2vdc so quickly. The motors require over I believe over 11.9vdc or the ecu will not allow the engine to run so your battery or electrical connections may be the issue? The TPS should be 0.6vdv and would recommend you adjust to specifications and if you get running well check throttle bodies are synchronised

I recommend you check the battery and electrical terminal connections at the battery to ensure the battery voltage maintains the correct voltage for the engine to run.


All the best with your bike

 

The "choke" is not a choke. Its just a fast idle setting. Have you checked both cylinder are firing?
Check fuel pressure.
I wonder if you have blocked injectors - since you were running a solvent cleaner through the fuel system.

 

Today when I was able to make a little more noise, I turned the idle screw up a bit and pulled the choke out and it did start. It took a little bit of cranking and throttle. Battery had been charging all day.

it did seem to get progressively better as it ran and I ended up with about a 1300rpm idle with the choke in. Best result so far. It does sound like it has some detonating going on. Is that common in these? I did not re map and it has no mods. Fresh 91 octane fuel.

 

You don't need 91 fuel and detonation is not normal. Maybe you are hearing something else and think it's pinging. You should be able to run it on 87 octane all the time. IIRC you put a bunch of injector cleaner in it, right? Maybe try to put just straight gas in it and see if this pinging doesn't go away.

 

Yes, I used SeaFoam on my last bike and the the bike ran like crap and the garage stunk after a ride. Once I ran enough clean 87 octane through the system the bike settled down and the smell ended. Additives are not always a good idea.

 

I ran the injector cleaner at the recommendation of my local shop because it had been sitting for years. When I drained the tank to put the new fuel filter in, I re filled it with fresh gas and no additives. My hunch is that the injectors are clogged. There is a shop locally who will be cleaning them this week. I’m going to pull them off and clean the fuel rail while I’m at it. Right now it won’t run enough to ride.

 

While injectors are being cleaned measure fuel pressure.

 

Still could be the fuel pump or the fuel pressure regulator. I seriously doubt the injectors are dirty or the problem, but anything's possible. They are not that easy to remove, and you'd need to remove them and clean them off the bike. While you're doing that, and you have the tank off, I'd swap the fuel pump and fuel pressure regulator.

Could also be: air leak somewhere you didn't know to check, crack in the intake boots you didn't see, failing ignition coil, bad plug wires, bad spark plug... I've even seen a spark plug that was cracked and the insulator came off along with the boot, would fire intermittently when it was all stuck together but obviously completely broken.

 

I was able to get a fuel pressure regulator and fuel pump with pickup, so I pulled the tank again and installed both. It just seemed like a fuel pressure issue. I decided to do that before pulling the throttle bodies and injectors to rule out everything in the tank. All of the rubber and vacuum lines and boots look brand new. This bike was stored in a climate controlled garage for the last 10 years... With those pieces replaced it instantly ran perfect. Problem solved! I don't know if i was the pump or regulator since I changed them both at the same time. With it running correctly, my TuneECU rig was very clearly able to show sensor readings and I was able to dial in the idle RPM and TPS setting with it warm. I'm finally back on the road. Thanks for everyone's help!

 

Glad you fixed it! BTW if you want to get rid of the "snatchy" throttle, use TuneECU and uncheck the box for O2 sensors. Then just disconnect the O2 sensors. You could also pull them and replace with a plug.

The root cause, most of the time this throttle feel is caused by the switchover from the closed-loop map (with O2 sensors) and the normal open-loop map, where there is a sharp step in AFR going from idle (closed-loop) to regular running. The O2 sensors input is really only used at idle, so eliminating them will make it use the static map all the time, which eliminates this switchover and smooths it out. Side effect is you may find it rich at idle and if you spend a lot of time idling, you probably will notice a drop in fuel efficiency.