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V7C Idle Problem

G

guzzipete

Tuned and Synch'ed
Joined
Apr 5, 2009
Messages
27
Location
Vancouver, WA USA
I took my V7C to my dealer late last month because it would not idle for more that 30 seconds and the front engine seal was leaking. I just picked the bike up today but not because it took that long to fix. I have been out of the country for almost 30 days.

The idle problem was caused by the engine running too rich at idle. The dealers black box indicated that the ecu was getting a false temperature reading from the engine temp sensor. That was replaced, but the idle problem remained. MG tech support suggested replacing the throttle position sensor and the ecu. After those were replaced the idle problem was solved.

However, when they put the bike on the dyno they found that horsepower was down. It is putting out 36 horsepower and in stock form that figure should be around 40. Their dianostic black box shows that the engine is running too lean above 3.5k RPM. They suspect that the Mistral exhaust I installed is causing that problem. I told them that I have the OEM units and can reinstall them. The head mechanic said not to do that just yet. MG tech support suggested trying a product called MemJet. It fools the ecu into thinking that ambient air temp is colder and denser than it really is and that will cause the ecu to fatten up the mixture. Their mechanic has one for his bike (a Triumph) and wants to install it first to see if the thing really works. If it does, I will order one for mine.
 
I think this will be of interest to quite a few V7C owners. I raised the issue of the bike running lean with the dealer and was told that it was all down to the ECU settings that he couldn't permanently change. Please can you keep us posted with the results if you get the chance?
 
Pete, if you're handy then think about making your own 'Mem Jet" out of elecrical components. I did that to create my version of the Fat Duc, and it's working well. This spring I'll dyno the bike with/without it and see for certain.
 
Hi Everyone. I too had a TPS sensors replaced under the warrantee.

My V7c started to run real rough, wouldn't idle at all.

I thought some soap from the last time I washed the bike, might have gotten into the unit past the seal, which I have had happen to me before, both on a Honda Goldwing and a ST1100. (this is over a 23 year period)

It is wet and damp here during the late fall, winter and spring, and I find the Moto Guzzi electrical connections to be very sensitive to the moisture.

I had a problem with my bike's starter relay a few times because of a wet connection under the tank. One connector connection had turned green and scummy. Cleaning it up and sealing the ends with some di-electric protection permanently fixed it.Most of the connectors that Moto Guzzi uses are the open to the environment.

My 2 yellow wire connector from the alternator to the harness also had some water in it, and the white plastic had started to deform a bit from the heat of a partial short....probably the soap residue problem again.

I wish the manufacturers would not place the power wire inter-connection terminals in the same connector housing.

I cut off the connector and wired the generator directly to the harness. Learned that lesson from the same exact problem happening to my Hondas.

The Guzzi's bikes electrical system has been flawless since for the last 9 months.
 
Part 2.... (broke my post into 2 parts to be an easier read) B)
Helping cold starts.

I commute a lot by inter-island ferry, (I live on a island!) and at the end of a 40 minute ferry trip, the bike has cooled off enough to be a real problem getting up the boat ramp. It would stall and stall and stall if I didn't get the revs up and slip the clutch. That is not good for the little bike and is publically embarassing!

I put on new NGK spark plug caps and installed BR8EIX Iridium spark plugs 4 months ago and that has helped alot with the cold operation - hasn't eliminated it but it is better and noticeably more consistent.
 
Penderic,
Re the cold starts; consider using a FatDuc or other aftermarket item to richen the air-fuel mix. I have a version I made myself, and it really helps starting. Most devices alter the reading from the oxygen sensor or the temp sensor, to the ECU, causing the ECU to richen the mix. A Power Commander would do the same thing, but that's $$$.

Joe
 
Cold start/erratic idle are a result of a few things on a otherwise mechanically sound bike... Valve lash adjustment & TPS setting, along with proper fueling (if the dealer has attempted a tweak otherwise). If all else is good, then a fueling revision is your best bet. Yes I have/recommend a Power Commander V and the new 02-Optimizer, which I now sell stand alone for a few $'s more then the CrapDuc, but this one really works like it should... more info here; https://www.guzzitech.com/forum/160/5950.html

Best to you and your ride in the New Year!
 
Thanks Joe & GT-Rx - I did put a FacDuc on the bike last summer and have played with it quite a bit now. I liked the middle of the range adjustment best.

Its not perfect.

There is a bit of backpopping exhaust and burble when the throttle is completely rolled shut but I can stop it 100% by not closing the throttle completely - maybe the balance or TPS just needs a bit of tweaking.

I havent tried the other inexpensive way of adding more resistance to the engine temp circuit yet. Looks like another good way to richen above the 4000 rpm zone.

I am looking at a system that varies the temp circuit resistance circuit automatically as another good way to modify the fueling. http://www.boosterplug.com/?id=Basic_Resistor_Tuning&menu=3 but I will probably try a simple resistor add on first.
 
My pleasure. I'm a decade in on resolving fueling on FI Guzzi's now, so you can fiddle/fool until your heart is content. When you are ready to resolve it perfectly, add a Power Commander and everything will get resolved 100%, including pop-on-decel. The thing I hear most often post install is "why didn't I do this sooner..."
Feel free to contact me direct when you ready.

Todd
Technical Advisor for all things Guzzi to Dynojet & Certified Power Commander Tech
 
Penderic, nice link. I like it that Boosterplug outlines everything; what the sensor does, various ways of altering it, and what Boosterplug does. I'm not keen on mysterious "black boxes" but Boosterplug is pretty open with what they are doing.

Like you said, a simple resistor (for $1) is a good first step, just to see how performance is altered. Keep me posted with what you find. This spring I'll visit the local dyno and get some real numbers for my alterations.
 
Got the MemJet installed today.

I am not going to say that it made a huge difference in torque or horsepower, but the first pull broke the dyno. :lol: :lol:

Didn't know that these little small blocks could produce that much power. :shock: :shock:

Actually the dyno had just been serviced and a new O2 sensor was installed. It was doa. Installing the old O2 sensor fixed the dyno problem.

The MemJet worked exactly as advertised. It fattened up the fuel mixture. There was a small bump in HP. The bike now has 38 HP at the rear wheel. Biggest change was throttle response. On the 30+ mile ride home, the bikes reaction to changes in throttle position was much smoother. The bike should also run a little cooler with the fatter fuel mix.
 
About three weeks ago I took the V7C out for the annual Spring Opener. Weather was grim, cold and wet. But we did ride 168 miles. This was the first long ride since I had the MemJet installed. The bike runs better than when it was new. The idle problem is gone. Fuel mileage remained the same. I averaged 51 miles per gallon over a mix of back roads and freeway with lots of stops. Also, the check engine light has never come on.

I am sure that any of the various devices that fool the computer to add more gas to the mixture will work equally as well.

Another thing that I have noticed is since I installed Ed's Sump Extender the engine seems to run quieter. However, It could be just my imagination.
 
Ruff idle may be bad gas. Alot of stations don,t sell much hi-test and you can get a bad tank full of farting wheezing stumble idle. Find a good busy station and stick to it.
 
I have the same problem. 2011 V7 classic, keeps stalling at idle, even when warm. I've read a number of forum posts but it all seems a bit more complicated than just turning a screw to adjust the idle speed.

Can anyone offer me a simple explanation on the idle speed problem?

My bike was serviced just 200 miles ago. I've just bought the bike so I don't know its history apart from what's in the service book.

By the way the bike starts ok when cold and hot and it idles about 1,000 RPM. When pulling away from cold the bike seems to "lack power", almost like its in 2nd gear.

I keep reading about "flashing" the fuel injection unit (I've no idea what that is, or how to do it), installing a "fat duc" (again, I've no idea what this does or how to do it) and resetting the throttle position sensor (how on earth do you do that?)

Help!
 
Last edited:
The 02-sensor handles idle and low speed/throttle fueling known as “closed loop.” At roughly 1/3rd throttle and ~3500 RPM, the sensor is not used and goes to a static map on the ECU (“closed loop”). This is a problematic area for many as it requires a timely warm up and low speed throttle is a major annoyance if you've been around bikes long enough.
The TPS is only electronically reset (i.e. a dealer or the Centurion-S software I offer; https://www.guzzitech.com/store/product/tr-centurion-diagnostics/)
I offer both an 02-optimizer; https://www.guzzitech.com/store/product/gt-02-optimizers/ - for a cheap and easy fix for only low speed throttle, or the ECU re-flash; https://www.guzzitech.com/store/product/gt-rx-15mrc-re-flash/ - which handles all fueling from idle to redline. This requires you to send me the ECU, and a TPS reset once re-installed.

Hope that helps, questions?
 
This requires you to send me the ECU, and a TPS reset once re-installed.

i'm confused. do i have to physically remove things from the bike and mail them to you?

i only use macintosh computers so i can't do the reflash thing
 
ds99 said:
This requires you to send me the ECU, and a TPS reset once re-installed. i'm confused. do i have to physically remove things from the bike and mail them to you? i only use macintosh computers so i can't do the reflash thing
Click to expand...
Yes you would need to remove the ECU and send it to me. The TPS reset can be done by a dealer.
 
ok, thanks. i don't want to start removing bits from the bike and mailing them across the atlantic!

its disappointing that Guzzi don't address these issues before releasing the bike. I guess that's italian manufacturers for you, if you want more reliability/less 'niggles', go japanese!
 
ds99 said:
ok, thanks. i don't want to start removing bits from the bike and mailing them across the atlantic! its disappointing that Guzzi don't address these issues before releasing the bike. I guess that's italian manufacturers for you, if you want more reliability/less 'niggles', go japanese!
Click to expand...
I get ECUs from around the globe.
These "issues" are unfortunately because of Euro Emission Regs, not Guzzi. If they could, they would deliver it spot on, bet on it.
 
The problem with that Boosterplug system is that the air temperature sensor does not have a linear resistance to temperature, it is largely exponential, thus a straight 10k resistor will have little effect at very low temperatures, but will enrichen the mixture far more than 6% at high temperatures. Look at the chart on that website, at 50 degrees it would be as if it were 10 degrees, ie. 12%increase in fuelling.
 
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