2007 Nevada 750 will not idle

[SIR REAL ED]

Hi everbody,

the nipple on the charcoal canister going to the back of the air box was broken off, so I decided to remove the charcoal canister.  I plugged both ports on the intake manifold, and the bike was running fine.

in the interests of preventive maintenance, I started unplugging electrical connections and smearing a bit of di-electric grease in the connections.  All of the connections looked good, except for one two-wire connector under the seat.  This connects a white wire with a red stripe and a green wire with a red stripe.  One of the wires was a bit fused to an adjacent surface, it was a bit corroded inside, and the white plastic was partially melted.  Obviously a sign of poor conductance creating heat.  All of the connections behind of the gas tank, including the ECU have been done.

When trying to start, the bike will only run for about a second and then dies.  But if you get the engine running at an rpm above 3000 in that second, the bike will stay running indefinitely.  Allowing the engine to drop below 2000 rpm makes it die again.  Touching all the connectors I have disconnected and greased, only the one mentioned above is warm.  Obviously, I need to re-clean or better yet, replace that connector.  I have not traced those two wires (white with red stripe and green with red stripe) back to their component yet. 

Interestingly, even with the ignition key off, when you disconnect and then re-connect that connector, the instrument panel lights up, and the tachometer and speedometer needles cycle CW then CCW.  Never saw that happen before.  I suspect with the bad connection, some information is being kept from the ECU that would allow the bike to idle. 

Anyone out there have a wiring diagram for this bike?  Or know what these wires connect to?  Did the throttle position sensor (TPS) lose it's position when I disconnected the ECU?  Is there a re-teaching procedure to set the TPS

So far, the "tinkering project" is fulfilling it's mission!   

Thanks in advance for your help.   

[oldbike54]

 First off , clean every bit of the dialectric grease out of every connector .

 Dusty

[SIR REAL ED]

First off , clean every bit of the dialectric grease out of every connector.

 Dusty

Thanks Dusty.  I knew I was going to hear that one.  I appreciate you being the better part of my conscience.  As the old saying goes you can learn from your own experience or you can learn from the experience of others.

Some people swear by di-electric grease, some swear at it.  This may be one of those times when di-electric grease is a bad thing.

In the past, I've never had any trouble with di-electric grease.  When I started doing this, I was thinking it may or may not work, I might just end up cleaning the grease out of these connections. 

On the additional information side, the two wires go to the pair of 30 amp fuses on the left side or the bike.

[John A]

Dielectric grease is an insulator and should only be used as a lubricant on the plastic part of the connection.  What you want is a conductive grease on the metal parts if anything.  De Oxit is a product I’m not very familiar with but it’s virtues are legend here. I’d like to have it explained to me for I have two little bottles, one a cleaner and one a shield.  Can you leave the cleaner on the contacts and just put the shield on top  of it or does the cleaner need to be removed?

[oldbike54]

Thanks Dusty.  I knew I was going to hear that one.  I appreciate you being the better part of my conscience.  As the old saying goes you can learn from your own experience or you can learn from the experience of others.

Some people swear by di-electric grease, some swear at it.  This may be one of those times when di-electric grease is a bad thing.

In the past, I've never had any trouble with di-electric grease.  When I started doing this, I was thinking it may or may not work, I might just end up cleaning the grease out of these connections. 

On the additional information side, the two wires go to the pair of 30 amp fuses on the left side or the bike.

 No attempt at being anyone's conscience , I learned that one the hard way . Kinda surprised Chuckie hasn't weighed in , or Kiwi Roy , or ...dialectric grease isn't a conductor , really kinda surprised the bike will run at all .

 Dusty

[SIR REAL ED]

No attempt at being anyone's conscience , I learned that one the hard way . Kinda surprised Chuckie hasn't weighed in , or Kiwi Roy , or ...dialectric grease isn't a conductor , really kinda surprised the bike will run at all .

 Dusty

I sincerely appreciate your opinion.  If that came across in any way other than appreciation, I apologize.

I know it is an insulator, but never had any problems with it in the past, even on ECU's.  I suspect, the more common usage in on spade or bullet connectors, and that on the smaller pin connectors (such as the ECU) since such little current is present, even a little resistance simulates an open circuit.

Last time I told a mechanic buddy regarding a different problem, that "I've never had that problem before."  He replied, "No one ever has a problem until they have a problem."

[malik]

Carl Allison's coloured wiring diagrams are available for download on Greg Bender's thisoldtractor.com website.

I'd also be plugging in Guzzidiag to check the possibility of any error codes logged in the ECU. It's not definitive, but if some of the sensors are not working properly that may be recorded there. Guzzidiag also helps in balancing the throttle bodies (which is best done after everything else has been sorted).

[malik]

And DON'T be tempted to play around with the "sacred screw".

[sign216]

This is a carb model, right?  How about checking the idle jet.  Cleaning it, and seeing if that helps.
Jow

[malik]

I think you'll find it's injected, Joe. 2007, with an ECU & the Californian special charcoal canister addition. Same as our Classics with the 15RC, but with different clothing.

[Chuck in Indiana]

To the best of my knowledge.. admittedly not much.. the Dielectric grease *isn't* your immediate problem. It *will* become a problem eventually, though.
Are you sure you don't have a big vacuum leak?

[SIR REAL ED]

Thanks for the continuing advice gents.  2007 is fuel injected.  Problem only surfaced after my rocket science project of di-electric greasing the connectors...... but I also removed the charcoal canister, but, IIRC had it running since then with no problem. 

Regarding removing the charcoal canister..... the spigots on the intake ports used for balancing the TB's are plugged.  Although one rotates freely while the other does not, that may be the source of the leak, but, it has been that way since I bought it.  The line that goes up to the gas tank has not been plugged, this has the valve body in line..... the line going to the back of the airbag has not been plugged, but since this line was broken off the charcoal canister, it has been open to atmosphere since I bought it.  So nothing has changed on this line.

I like the idea of the vacuum leak as the cause, so I will check the intake port plugs and plug the other two line that came from the charcoal canister. 

I spent some time cleaning the connectors to remove the di-electric grease, but no improvement to date.  I plan to do some more cleaning.

It is possible that something went belly up while I was messing around, but I think that is a bit too much of a coincidence.  Easier to believe I caused the problem.

thanks again for all your help.  I'll look for the wiring diagrams.  who sells guzzidiag?

[SIR REAL ED]

And DON'T be tempted to play around with the "sacred screw".

Luckily, Pete Roper warned me that this would land me in Purgatory.  Should be a giant sticker on the gas tank saying the same.  And on the cover of the owners manual and service manual.

I don't understand the Guzzi FI system enough to know why not to touch it, but I do know enough not to touch.

[malik]

The sacred screw is to be found on the left hand throttle body. When the bike was new, there would have been a blob of yellow paint covering the end. It is a throttle stop (?) set at the factory on an expensive electronic gizmo, just for that individual set up.

Guzzidiag is a suite of programmes you can download - free, but donations gracefully accepted - that can read & write to the ECU. You'll need Guzzidiag, the reader & the writer for your ECU (which should be the 15RC), and perhaps Tuner Pro for later on. You will also need the cables to connect your computer to your ECU - I got mine from Lonelec in the UK. Full instructions & links can be found on www.griso.org, as well as on here. Those instructions pertaining to the 2TB V7's, Breva & Nevada are the ones you want.

[Kiwi_Roy]

I can't figure out from the schematics available what the two wires are but from the way you describe the action of the dash it may be the supply to the ECU or dash just cut the connector out and crimp it together with a butt splice or solder, you can always cut it again if you need to break the connection.

I'm not a fan of di-electric grease either, I have my favourite Petroleum Jelly aka Vaseline I use where I want to stop corrosion.
I don't believe there is such a thing as a conductive grease, even copper coat doesn't, certainly there are other liquids that conduct, dirty water and acid but you wouldn't use those would you.
A organic paste like vaseline doesn't help conduction but it displaces the water and Oxygen that would otherwise cause corrosion.

[SIR REAL ED]

I cleaned up the connectors, and everything looks crystal clean.  Same situation exists.  Pulling the plugs, and checking for spark, spark is great for about 2 seconds then disappears, just like a kill switch was activated.  I think I will splice the two most questionable wires together and see if by some chance they are somehow vibrating apart.

Seems like at times it is engine speed dependent, drop below 2000 rpm and it quits, other times it seems time dependent, 1-2 seconds of spark or running and then it quits.

I also plan to look at the wiring diagram, and read up on the fuel injection system.  Seems like ordering Guzzidag and some cables in not too far in the future.  Maybe an error code needs to be cleared.  Interesting situation.

[guzzisteve]

Here is the leads that I use for Diagnostics- you were asking were to get in USA

https://www.obdinnovations.com/kkl-obd2-usb-cable-ftdi-ft232rl-chip-3-pin-adapter-cable/

[SIR REAL ED]

Here is the leads that I use for Diagnostics- you were asking were to get in USA

https://www.obdinnovations.com/kkl-obd2-usb-cable-ftdi-ft232rl-chip-3-pin-adapter-cable/

Thanks Steve.

[malik]

That high idle, then cut out is a worry. I'd also be checking the basics - check the throttle cable action, especially at the throttle body end (you may have to clear some of the fancy bodywork off to see), & check the operation of the fast idle cable, ensure the airbox is clean and the filter fresh, check the spark plug caps & HT cables with an ohmmeter (multimeter set to ohms) & the connection to the coils, check the integrity of the rubber manifolds, try fresh spark plugs. I'd also check the state of the connector between the alternator & regulator (2 yellow wires in and out - a known weak point on the 2TB bikes) and the lambda connector (usually tucked in behind the starter motor) - you could even just unplug the lambda temporarily & give it whirl, see if there's any difference. As everything seems interconnected, I prefer to check out all the things I can first, before getting to he bits that require money or expertise I don't yet have.

[SIR REAL ED]

Yes Virginia, there is a god and he loves me!  Or at least he looks out for old fools and small children.

My puny brain finally engaged as I was looking at those four black cubes under the seat (one of which is the fuel pump relay), I kept thinking "What would kill the spark?"  Other than the kill switch, nothing comes to mind.

One of those cubes (see picture) was not positioned properly in its holder when I started cleaning connectors, and cleaning the rubber holders with Armour-All.  Oddly enough, it only fits one way in the rubber holder, and the holder is marked "UPPER" with an arrow.  Bizarre.  So after treating the rubber holder and cleaning the connector, I put it in the proper position.

Today I took it off, connection looks clean, but if you shake it, it sounds like a rattle spray paint can.  Hmmm, an electrical component with loose parts inside?  Could this be the tip over kill switch that is rumored to exist?  Get out the meter and the two leads are a closed circuit.  Rotate it every which way and the circuit stays closed.  Hmmm, would the tip over kill switch, if that's what it is, default to an open circuit when running or a closed circuit?  Could this thing be toast?

Lets try starting the bike without this "thing" connected.  Bingo, runs perfectly!

Almost too obvious in hindsight.  Just a couple steps behind "Is your kill switch on?"  "Are you out of gas?"

Guess what isn't getting reconnected?  Although I see it can be taken apart, so I will probably do so just for fun and to try to salvage it.

Thanks to everyone for their help.  I really appreciate it.  Best site I've found yet.

[SIR REAL ED]

That high idle, then cut out is a worry. I'd also be checking the basics - check the throttle cable action, especially at the throttle body end (you may have to clear some of the fancy bodywork off to see), & check the operation of the fast idle cable, ensure the airbox is clean and the filter fresh, check the spark plug caps & HT cables with an ohmmeter (multimeter set to ohms) & the connection to the coils, check the integrity of the rubber manifolds, try fresh spark plugs. I'd also check the state of the connector between the alternator & regulator (2 yellow wires in and out - a known weak point on the 2TB bikes) and the lambda connector (usually tucked in behind the starter motor) - you could even just unplug the lambda temporarily & give it whirl, see if there's any difference. As everything seems interconnected, I prefer to check out all the things I can first, before getting to he bits that require money or expertise I don't yet have.

Agreed.  All good advice.  I replaced the plugs as a quick check.

New air filter, along with replacing the half plastic fuel filter, and in tank fuel line are still on the list.  Then I'm just a turn signal and a rear brake pressure switch away from passing inspection.  Always makes sense to me to address known issues before they become problems.

Still working my way forward on the bike when it comes to cleaning electrical connections.

[malik]

Well found, sir. I would never have guessed the culprit. When my tip over sensors work, the start button doesn't function at all (and, by the way, I've never actually found them, neither on the Classic nor the Special, whose sensor is a little dodgy - they seem to keep changing the place where they lodge them). It good to have a picture of one - now I know what it look for, I should at least try to find the one on the Special before putting the engine back in. Access should be easier.

[oldbike54]

 Cool 

 Dusty

[guzzisteve]

Ha Ha,   HEY is your tipover switch tipped. good find

[SIR REAL ED]

Thanks for all the encouragement.  Even a blind hog finds an acorn every now and then!

"Against stupidity, even the gods struggle in vain!"

I'll post some better pictures tomorrow.  I understand the function from a safety perspective, but like side stand switches, and clutch switches, it all seems a bit over done to me.  Might not be smart, but removing safety switches to avoid future problems is a task I find satisfying.

Evidently, over 2000 rpms the vibration changed just enough to let the thing turn into an open circuit.  I kept thinking rpm sensor or timer (1-2 seconds of running) going bad, and I really was not sure the bike even had a tip over sensor.  I think I have seen it called a "bank angle sensor" in the wiring diagram from thisoldtractor.com.

Well on at least one Nevada it is right next to the tool tray, under the seat. 

Thanks again for all the help. 

[SIR REAL ED]

So, should I smear a big hunk of di-electric grease on all the ECU pins now?   

[Chuck in Indiana]

So, should I smear a big hunk of di-electric grease on all the ECU pins now?   

While you'e at it, taking the relays apart and packing them, too, would be a great idea.
I'm here to help..

[chuck peterson]

Congrats! Ive vowed to not look under the seat....too many wire thingees

[SIR REAL ED]

Well found, sir. I would never have guessed the culprit. When my tip over sensors work, the start button doesn't function at all (and, by the way, I've never actually found them, neither on the Classic nor the Special, whose sensor is a little dodgy - they seem to keep changing the place where they lodge them). It good to have a picture of one - now I know what it look for, I should at least try to find the one on the Special before putting the engine back in. Access should be easier.

Malik,  FWIW, I think that engine is too pretty to hide in a motorcycle frame.  Looks pretty damn good where it is.  Might want to put it in your living room, so the whole family can enjoy it.

Below are the promised pictures.  Good luck finding the "thing."  Who knows what yours looks like, I've shown you mine.








free hosting images

[SIR REAL ED]

While you'e at it, taking the relays apart and packing them, too, would be a great idea.
I'm here to help..

I like the way you think.  Since both bearings and relays have moving parts, it stands to reason that packing both with grease makes them last longer.  You'd think the Italians would put grease fittings on the relays to make greasing them easier..... like the Germans do.

Good question to ask the seller next one is looking at a used bike:  "So, how often did you repack the relays with grease?"  When they get that confused look on their face just look down, shake your head, and mumble under your breath "I'm talking to an idiot, I'm knocking another 10% off the price."

Back to the shop.... I know I had a 5 gallon bucket of Cosmoline laying around out there somewhere.