V7ii hesitation...cannot find why! FIXED

[Alchemist]

Hey folks,

So I've got a V7ii (2015), had it for around 6 years.

It's recently developed a really annoying hesitation, especially when pulling away at lights. Would welcome some advice. For context here's some recent history and things I've tried!

I change the plugs every year, but wasn't doing the leads, so was on the original leads. Then in December 2025 it developed a bad misfire, was the right plug lead/cap arcing on the head. I changed all the leads and used NGK (5kohm, slanted) ones as the orig are non-available. All ran fine after. Bike had covered 23,500 miles.

Them in August (8mths later) started hesitating under acceleration, if you opened the throttle wide it was bad enough to cause the traction light to kick in.

Traced that to one of the NGK plug caps on the right cylinder (so only 8mths old, hence took some time as I didn't expect it'd fail that quick), which I replaced with a new (old stock) cap. Also fitted new spark plugs and plug leads. Has run fine since August.

The hesitation has now returned again! I've swapped both coil packs and both plug lead caps. I've also put a bottle of injector cleaner through the tank and changed the fuel filter (and discovered it had the original half plastic one! All metal now fitted in the tank).

When riding it's as though the spark or fueling is weak. If i open the throttle gently it'll get up to speed, and at speed/higher revs it's less noticeable. But low speed, especially pulling in 1st and 2nd it's really annoying. Any ideas? I can inspect the plug leads again (maybe a poor connection) or perhaps fuel related, like a lazy injector or air leak? I did wonder if the fuel pipe had kinked when removing the tank but doesn't seem so. Would welcome any thoughts!

[scra99tch]

Not sure if its afflicted these bikes but do they also have tank suck?  After riding for a bit stop and open tank listen for and rushing air or even hard to pull gas cap out? 

My vent hose became plugged, or it may of been tip over valve was faulty gummed up and I had to release the overflow hose from the front of the tank to make it back home. 

[chuck peterson]

Full tune up? I know mine is due at 24k

[Dirk_S]

Did your previous fix attempts include resetting the ECU, via disconnecting the ground? If so, maybe replacing plug leads etc wasn’t what made everything go well again. Instead, maybe it was the ECU reset? Possibly a sensor gone bad? Have you checked for vacuum leak (doesn’t sound like the issue but worth checking nonetheless)…

Do you have GuzziDiag?

[malik]

Here's a few things to try -

Check the air filter & that there's no oil in the bottom of the air box, I've found the 1TB models to be sensitive to the cleanliness of the air system. Oil vapour (from the rocker cover breathers) goes up the manifold & interferes with the MAP sensor, so clean up the oil with paper towels as well as down the manifolds at least as far down as the tiny hole that the sensor reads from. I used some MAP sensor cleaner spray.. a severe case of oiling results in all sorts of running problems. The longer term common fix is to use less engine oil when refilling on the oil change - I use 1.9L on my 1TB, although I've heard others use even less.

Re-set the TPS - get hold of a copy of Guzzidiag & the map for your model (still the MIUG3, I think) connect it up & highlight the windows for RPM & the TPS activities & see if the screen shows the hesition on throttle. Check the fault log. Then re-set the TPS & re-set the auto learning. The actual routine is fully laid out in the Guzzidiag thread found on here in the archives.

If you don't have Guzzidiagm the ECU can be re-set by disconnecting the battery's -ve terminal for half an hour or so, then re-connecting & test riding.

Clean & lubricate the TPS itself. The TPS is a potentiometer, and dirt & corrosion can impede its smooth action, take the TPS out, 2 screws mm clean up the base area & lubricate it. The last time I did mine I used contact cleaner & a rag then a very thin film of white lithium grease. Worked a treat, fixed the high idle problem  the 2TB was having,

Check the spray pattern of the injectors - for each of the injectors disconnect one, hold up a section of paper towel & crank the starter (ignition on). The spray pattern should be even.

Pull the injection relays & clean the contacts & the relay bases. Test them with a multimeter if you can figure out how to do that - there's info online for that.

Ensure that your battery's terminal are clean & vaselined. Remove the earth's on the bell housing end, clean & vaseline them, just in case.

A failing engine temperature sensor can introduce aberrant behaviour, this may or may not show up in the ECU fault log.

The tank cap itself has a breather hole, ensure that this is clear - you might have to take the cap apart.

What fuel are you using? I've found that my V7s don't particularly like the premium or high octane ones. 91 & 95 unleaded here in Oz are fine, but problems with 98.

I shall check my log to see if there's anything else I've come across in the 164,000km on my 1TB & 240,000km on the 2TB that might be relevant, but here's a few things to keep you busy in the meantime.

Good luck,

[Alchemist]

Thanks SO MUCH everyone for your prompt replies, has given me plenty to go at and I really appreciate you taking the time to give me some advice.

So a few updates:

Air filter boxed is clean (I've had oil in it before, so know to keep an eye out for it. When it did have a pool it before it didn't affect running).
Petrol cap I've blown through the hole and also run it with the cap loose, which made no difference.
Battery connections are good (battery is also only a few months old). I've disconnected it this morning for 30+ mins and refitted.
Large earth connection atop bell housing I've cleaned and refitted the cables.
I was going to remove the large y-shaped black inlet manifold and TPS but I don't have a spare of the circular rear clip on the Y shaped manifold, so will need to get one before I do so (in case I can't refit it - a jubilee would be much better! I also noticed there's a nipple poking up off the top of the Y at the ECO end with nothing attached, is this correct? Some kind of vent? Looks like it should have a pipe/breather on it of some sort.

I think the next step is to get GuzziDiag, clear the fault codes and then see what it throws up (crankshaft/engine speed sensor perhaps)?

Have just taken it for a spin, when you're not opening the throttle hard it's less noticeable. I also noticed with the revs up the power is held back but then suddenly kicks in an instant surge, which feels like the bike is trying to run as it should but is being held back.

The other thing to consider is i could have got unlucky with the replacement coil packs I've fitted (used), and both sets (original and replacement) are faulty? Seems unlikely but hopefully GuzziDiag will reveal something. Any other suggestions welcome!

[Alchemist]

Sorry - me again. If someone can also point me to where to buy GuzziDiag hard/software (ideally for Mac, although I can gun up an old Windows machine if that's better).

Or something all in such as a GTM Flash Tool (where i can reset the TPS)? I can have a go at removing but don't want to damage anything as I'm using the bike daily

[Dirk_S]

…I also noticed there's a nipple poking up off the top of the Y at the ECO end with nothing attached, is this correct? Some kind of vent? Looks like it should have a pipe/breather on it of some sort.
…

Are you talking about this port?


That’s the connection to the evap canister, which if still present on your bike, should be the black barrel located right around there.



If the evap canister is still there, you’re missing a hose. If the canister isn’t there, the previous owner removed it, and they either failed to blank off the port or it fell off.

If that’s not blanked off, I wonder if that may be related to your woes. Without that port closed off, I imagine you should be experiencing some idle surge.

[Dirk_S]

Sorry - me again. If someone can also point me to where to buy GuzziDiag hard/software (ideally for Mac, although I can gun up an old Windows machine if that's better).

Or something all in such as a GTM Flash Tool (where i can reset the TPS)? I can have a go at removing but don't want to damage anything as I'm using the bike daily

Link for GuzziDiag and necessary tools:

https://www.von-der-salierburg.de/download/GuzziDiag/

There are a couple good threads on here on it as well. Easy search

[Kev m]

FYI you can't remove or service the TPS, it's part of the MUIG3 combination ECU/throttle body. You can only reset the base value.

[Vagrant]

I have to ask. Did you screw the plug caps onto the wire or just push them in. I'd pull them apart and cut 1/2" off the wire end and re-screw with a shot of Deoxit or petroleum jelly.
Did you get real plugs from Auto zone or did you get some possible knock offs?

[Moparnut72]

I have all the cable for the diagnostics. You can have them for the price of shipping, I traded my V7 and no longer need them.
kk

[Alchemist]

Hey folks, so the evap can is non existent, but I can't imagine the previous owner removed it (he bought the bike new, only covered 4k and was by the book). Maybe it fell off - very odd. Either way thanks for helping me identify the nipple, I've now blocked it off.

On plugs/caps - yes, properly screwed in with and with a dab of contact cleaner for good measure (also removed to check for a good contact and refitted, as I've seen the inner pins bend in the past and miss the centre of the cable).

Thanks also for the cable offer! I've ordered this from eBay: https://www.ebay.co.uk/itm/306476425009 I'll see if it allows me to rest the TPS (as well as the ECU) and go from there. If I can't do the TPS I may take you up on that cable - thanks, really kind of you.

[Dirk_S]

Hey folks, so the evap can is non existent, but I can't imagine the previous owner removed it (he bought the bike new, only covered 4k and was by the book). Maybe it fell off - very odd. Either way thanks for helping me identify the nipple, I've now blocked it off.

Reset your ECU (pull the negative terminal off for at least 15 minutes or so), and start her up. Let’s see if that was the issue. That’s a major vacuum leak, so it had to have been causing at least some issues.

[Kev m]

That’s a major vacuum leak, so it had to have been causing at least some issues.

I mean it's a TINY pinhole - I don't know that I'd call it a MAJOR vacuum leak - it's just a teeny tiny bit more air than the ECU THINKS the throttle plate is letting in. I don't think that's it, but it's good that he found and blocked it.

[Dirk_S]

I mean it's a TINY pinhole - I don't know that I'd call it a MAJOR vacuum leak - it's just a teeny tiny bit more air than the ECU THINKS the throttle plate is letting in. I don't think that's it, but it's good that he found and blocked it.

“Significant”, “Requires attention”, “Will cause issues”, “Leave open and risk lifelong constipation and/or diarrhea”…choose whichever synonym you’d like, but I reckon, from all my readings on the topic over the years, that leaving it open is unwise and consequential. But you’re more the expert in this matter—happy to be corrected and learn a thing or three.

[Kev m]

“Significant”, “Requires attention”, “Will cause issues”, “Leave open and risk lifelong constipation and/or diarrhea”…choose whichever synonym you’d like, but I reckon, from all my readings on the topic over the years, that leaving it open is unwise and consequential. But you’re more the expert in this matter—happy to be corrected and learn a thing or three.

I think there's a VERY small possibility it could cause issues over time with a small increase of dirt or other contaminants ingested through that hole - but again, it's tiny, so it might clog and close itself before it did any actual damage.

I also don't really think it's effecting mixture to any real amount. If anything it barely effected it when it was attached to a charcoal canister that had some HCs to draw.

I dunno - I absolutely could be wrong, but I be it doesn't mean jack except to anal-retentive people (LIKE MYSELF) who would absolutely cap it if it was otherwise open, but probably would still be fooling myself that it mattered.

[michaell32]

That picture makes it look much larger than a pin hole. Looks closer to 4mm or so. I can easily see that affecting idle and sub 10% throttle. The lambda sensors should be able to correct for it however there might be a limit on the LTFT correction or the closed loop portion of the map might not account for idle. Im not too familiar with these ecus. Time will tell if it's fixed but I would recommend riding the bike now that the port is plugged so it can adjust for it corrected. Im also not a fan of vacuum caps. In my experience screwing a bolt into the end of a hose has been much more reliable.

[Kev m]

I could be remembering wrong. But I thought the actual inside diameter of the fitting was much much smaller than the hose barb.

But like you said, OP can test and see.

[Dirk_S]

Thanks also for the cable offer! I've ordered this from eBay: https://www.ebay.co.uk/itm/306476425009 I'll see if it allows me to rest the TPS (as well as the ECU) and go from there. If I can't do the TPS I may take you up on that cable - thanks, really kind of you.

I just looked at the eBay link to the “Guzzi scanner”; it states that it’s for Euro 4, but the V7 II was built during Euro 3 reg. No idea if that affects its ability to read codes properly. That said, if you want to ever install a custom, affordable, good-working map from Beetle, you’ll need GuzziDiag and the proper cables to go from diag port to USB.

[Alchemist]

Hey folks, apols for silence. Had a week off/away and now back. So to update, I blocked the breather on the Y shaped manifold, helped a bit but not fixed the issue.

Today I've fitted higher spec leads, new plug caps (just for peace of mind really).

The eBay code reader found nothing, but as above, think it's limited in what it can do for my bike. Gonna ride it tomorrow but I'm fully expecting it to be as it was. Next step is to try GuzziDiag but looking at that page, I'm a little nervous about which to download and how to run it - looks a bit over my head. Anyone in Surrey/London area who could show me the ropes? More than happy to pay.

Also called a garage today, weren't that helpful said to find someone who can run/test it on a rolling dyno...and they don't have one! Is there a off the shelf tool I can buy to reset the TPS?

[Alchemist]

Hey folks...so I think I've found the culprit. Almost so simple it's embarrassing, but I'll tell you anyway if it saves anyone the same and you can tell me I'm a massive plonker.

So checked the back tyre today (check them once a month) and it was v low pressure wise. I'd not spotted it before as even with no air the tyres hardly sag, it's like new tread wise and I only pumped it up a few weeks ago (although bike was squirming a little last week, but I'd presumed it was the rain) Anyhow pumped it up and bike ran as normal (ie blissful to ride), no more hesitation!

So I'm presuming the rear wheel sensor somehow senses that the rear is low vs the front (maybe the ABS sensor counting more revolutions) and limits the power, which would explain why it felt like the bike had a weak spark.

Reason I'd not clocked it, is I'd have expected a warning light to come on highlighting it was in some kind of limp/limited power mode, but clearly not (got the off flash of the traction control every now and again).

So I must have a slow puncture. But either way, it's running (and I've learnt alot along the way, despite 7 yrs ownership). Thx folks!

[Dirk_S]

Man, that’s partly on us for nobody mentioning to check it. Yeah, the TC will indeed cause some jerking funk if turned on and the tire’s low.

[Alchemist]

Man, that’s partly on us for nobody mentioning to check it. Yeah, the TC will indeed cause some jerking funk if turned on and the tire’s low.

ALL down to me. I've had the bike years and maintain it myself, so not like I'm a newby. And had low tyres before but never had it cause permanent hesitation without a static warning light - more just while the light flashed when it lost grip. Didn't realise the V7ii was advanced enough to limit it's performance in that way for extended periods without some kind of longterm warning being triggered. So be aware fellow riders!!!

[Kev m]

Hey folks...so I think I've found the culprit. Almost so simple it's embarrassing, but I'll tell you anyway if it saves anyone the same and you can tell me I'm a massive plonker.

So checked the back tyre today (check them once a month) and it was v low pressure wise. I'd not spotted it before as even with no air the tyres hardly sag, it's like new tread wise and I only pumped it up a few weeks ago (although bike was squirming a little last week, but I'd presumed it was the rain) Anyhow pumped it up and bike ran as normal (ie blissful to ride), no more hesitation!

So I'm presuming the rear wheel sensor somehow senses that the rear is low vs the front (maybe the ABS sensor counting more revolutions) and limits the power, which would explain why it felt like the bike had a weak spark.

Reason I'd not clocked it, is I'd have expected a warning light to come on highlighting it was in some kind of limp/limited power mode, but clearly not (got the off flash of the traction control every now and again).

So I must have a slow puncture. But either way, it's running (and I've learnt alot along the way, despite 7 yrs ownership). Thx folks!

Sorry I think you pulled a Kev and confused us with too much info.

Because I just reread your OP and you friggin told us. We should have noticed it:

Them in August (8mths later) started hesitating under acceleration, if you opened the throttle wide it was bad enough to cause the traction light to kick in.

[nmroadrunner]

Good catch! 

[kingoffleece]

Start at simple and move on from there.  Best mechanic I ever knew started every project that way.

[Vagrant]

After market TPMS

[Bulldog9]

Thought I replied here, but it may have been on ADV or another site that this sounds like a TC calibration or tire pressure issue triggering the TC.

Glad it's sorted, and yes please do check your tire pressures at least weekly, or add a TPMS.