02 Califirnia stone bucking, and popping back under load.

[s1120]

OK, so I started this under a sidestand switch issue..  But its more then that .

This bike has 9k miles on it. It just started bucking and and popping back under any kind of a load on its last ride. Olmost sounds like a timing issue to me...  but I could do wrong. OK so here is the list of things ive done so far.  I reset the TPS about 25 miles ago. It seemed fine at that point, with no hitches in it. I balanced the TB's at that same time. It was running pretty good. After the issue started I disconnected the sidestand switch.. no change. I also pulled the engine speed sensor and cleaned it. No change...  I checked the plug wires..  Just the wires were within a smidgen of the 5K ohms rating listed on them. no rubbing on fins, or any other metal. A tiny bit of tracking on one boot, that I cleaned and used dielectric grease on. ..No change...  I checked ohms on the wires, to frame through the coils...  It was showing 8k but then increasing the longer I held the leads on. Is that normal??     Checked all wires, and connections on battery.  All good. Fuel tank is clear and flows fine. All that was went through about 500 miles ago. Not bad gas. I have about 150 miles on the gas in there, and its ran fine..  So when it pops back, it comes back through the TB's, at times... but its a clear skip under load. Motor runs fine at idle.. starts right up....  So my past diag experience with cars, makes me think timing...  Im really looking at the engine speed sensor. I read that most of the time the failure is no start... and this starts fine.

So that's where I am.....  any thing Im missing? Anything I should be checking??   How do I test the engine speed sensor? [its the one up in the timing case... this does not have the one on the flywheel]  Thanks for any help!!!  My daughter was pretty bummed... we were heading out for a long ride.

[s1120]

OK... a few other things.....  I wiggled the ingnition switch wile it was doing it, and no change...  Also after I shut it down, I flipped the kill switch off and on a few times, and still acted the same...  The bike has mostly been indoors... not a lot of weather/water damage from being out in the elements. …   

[guzzisteve]

TPS

[s1120]

TPS

I haven't gone back in to check it...  but maybe I sped its failure along when I adjusted it the other day???  Ill check the connection....  just incase its slipped apart.

[fotoguzzi]

Could your tps setting have slipped?
 After syncing the carbs did you close off the manifold ports?
Air l leak at manifold /air box rubber?

[beetle]

Check the TPS is linear. With the multimeter attached, slowly open the throttle. Make sure the voltage rises incrementally.

[malik]

Check the TPS is linear. With the multimeter attached, slowly open the throttle. Make sure the voltage rises incrementally.

Or if you have Guzzidiag - connect it, pull up The TPS & RPM windows, start it up and check the TPS fluctuations at various revs. Flat spots in the TPS will be obvious by the wider range of fluctuations. (I've heard there's supposed to be a graphical view in Guzzidiag - haven't found it yet, but if it works there, I might be even more obvious).

Other things, just to eliminate - Ensure your air filter is fresh & air box clean. Triple check battery terminals solidly screwed down & earths good. Injectors clean.

[s1120]

Ill check out the TPS in the morning. Thanks

[Vagrant]

I've had this or similar on the 01. I'd replace every fuse and all relays and clean up their contacts first. this always cures it. might not hurt to flush the ignition switch with electrical cleaner oo. make sure you put a thick rag under the fork so it doesn't run down onto the fender.

[Guzzidad]

   You say your fuel tank is clear and flows fine. Are you sure? I had the exact same symptoms on my 01 EV once. Turned out to be a broken wire to the electric fuel petcock. The fuel pump was strong enough to pull some gas past it at idle and slow speed. But under higher demand for more gas it was being starved because not enough gas could get past the closed petcock. The spring that closes the petcock isn't all that strong, but strong enough to stifle the flow of gas under high demand.

[lucian]

Carbon track on plug cap sounds a likely culprit. Give it a good eyeball in the dark with engine running . Could be a bad plug also,.especially one that was miss firing due to a shorted cap and got fuel fouled.  I'd change em out for what it costs, could be that simple.

[Chuck in Indiana]

Carbon track on plug cap sounds a likely culprit. Give it a good eyeball in the dark with engine running . Could be a bad plug also,.especially one that was miss firing due to a shorted cap and got fuel fouled.  I'd change em out for what it costs, could be that simple.

Agreed.

[Kev m]

I would lean toward the tps in this.

But I had a bad ignition switch on a Jackal that passed the wiggle test but showed itself with the tap test.

I try to make sure I perform both when I have a question.

Wiggle tells you if it is the wiring/connector.

Tap tells you if it is something intermittently loose inside the housing.

[Kiwi_Roy]

You say just the wires were 5K, do you have that rotten carbon core lead, with resistor caps, sometimes the carbon core starts arcing at the ends, a temporary fix is to jamb a sewing pin up the core to get a fresh connection. My EV came with carbon core stuff as well as resistor caps.
I believe you should only have one resistor in the circuit plus the coil which is a high resistance winding
I think from memory measuring from the cap to chassis is somewhere about 8k (thru cap, lead and coil to chassis) 5k for the cap + 3k for the coil, don't worry if it's not that but each side should be the same within 100 Ohms or so.

If you have a weak spark it will cut out when you give it a hand full of throttle.

If you see a meter reading that continues to climb like that it's a sign of some corrosion, the meter current is charging it like a battery, reverse the leads and you will get a different reading because the cell is offsetting the meter.

The thing is you have two cylinders if its cutting out on one it shouldn't buck, sounds like both are quitting perhaps the ECU is dropping off and resetting.
I always suggest adding a light to monitor ECU relays, just wrap one wire around the relay 87 pin and the other to chassis

http://www.thisoldtractor.com/guzzi007/schematics/2002_Stone.gif

The light can be wrapped around the 87 pin of relay (50) There shouldn't be the slightest flicker, just a light solidly ON
Relay (50) will drop out if the Engine Speed sensor is acting up.
If it is turning off then move the light back further perhaps to the coil of relay (52)
Fuse 1 as shown is at the interface between the rest of the bike and the brains that's another easy spot to access just downstream of a lot of flakey wiring, there too you should have a solid light. I have even convinced a few owners to put a permanent light on the petcock fuse as the first point of troubleshooting.

Yes Kev, my new V7 has a permanent light on each relay LOL

[Tom Farley]

My '00 Jackal around 75k miles started bucking and coughing under load, ran fine at idle, worse when ambient
temps high. I did a lot of what you're doing, replaced the tps, temp sensor, plugs, wires etc.

After wasting many hours and dollars chasing electrical glitches, finally shifted focus to fuel delivery. The answer was a new fuel pump from MG Cycle, $60 and 20 minutes to replace. Instant cure.

[Kiwi_Roy]

Tom, he only has 9K on the bike but on that note you can check the pump with an ammeter by taking out the right most relay and measuring the current draw of the pump between 30 and 87, just over 4 Amps is normal, don't turn the key On, this runs just the pump.
How noisy is the pump, that bike will plug up the filter with rust if it spends its life outside in which case the pump internal relief will lift at around 70 psi with excess current. A plugged filter will cause the bike to bog down, ask me how I know.

[s1120]

Tom, he only has 9K on the bike but on that note you can check the pump with an ammeter by taking out the right most relay and measuring the current draw of the pump between 30 and 87, just over 4 Amps is normal, don't turn the key On, this runs just the pump.
How noisy is the pump, that bike will plug up the filter with rust if it spends its life outside in which case the pump internal relief will lift at around 70 psi with excess current. A plugged filter will cause the bike to bog down, ask me how I know.

Fuel system was sparkling clean. I drained tank, cleaned screen on petcock. No dirt, varnish, rust or anything. filter was not replaced, but removed and dumped over winter, and nothing but clean, clear fuel...  Pump sounds normal nothing out of the ordinary for a electric pump. Petcock make the sound it makes when it turns on..  Really the fuel system is better then any bike I have had.. I doupt its got to do what that.

[s1120]

OK, pulled the plugs and the right bank was a little more carbon then the left... They are neither bad...  but the right is a little darker. FYI these plugs have about 500 miles on them. I cleaned and reattached battery, and checked the tps. Im getting a tiny hiccup... but I think its my cheap VOM. its smooth up till the changeover from 1.9-2.0 vt...  its got a tiny flash of "OL" at that point where it changes from x.xxx to x.xx format.....  Im going to try another meter to see if its just that changeover point, or if its a catch in the TPS.. But really...  its suck a tiny blip... I doubt you would feel it.

So Im going to try another plug wire on the pass side..  see if that makes a difference.

[pehayes]

I don't think the computer acknowledges "...tiny..." blips in the signal.  You either have a linear signal from the TPS or you have a stepped signal.  The latter is going to wreak havoc with map computation.  You might try to clean and reset the TPS before investing in a new one.

Patrick Hayes
Fremont CA

[s1120]

tried a different meter and it was fine   perfect clean sweep... So TPS is fine.. 

[LowRyter]

My 98 EV has done it intermittently.  TPS change has helped but not eliminated it.  Mine has two phases, one is under load as mentioned, the other under minimal throttle and no load.  It's largely gone now.  I noticed that keeping a charger on the battery seems to help. 

Honestly, it's a ghost.  Mine has been running well for a while.

[s1120]

OK, a new plug wire didn't do anything..  I didn't think so, but you gotta try...   OK, so now its starting to get worse. Its becoming hard to start now also, and some times will not idle...The popping back happens at more often when giving throttle.  So whatever it is gradually getting worse.

[Tom H]

Maybe I missed this. Did you make sure the TPS didn't move, screws loose?

If it was running great after the TPS adjustment IIRR, what did you do/change?

Tom

[s1120]

Maybe I missed this. Did you make sure the TPS didn't move, screws loose?

If it was running great after the TPS adjustment IIRR, what did you do/change?

Tom

Ya the TPS did not move. The setting was the same as it was before. I did set that, and the throttle body balance about 50 miles ago, and ran great. It does need a remap...  past owners never adjusted to the open air, and muffles..  But it was running great. Better then ever. Until it started popping back a bit, and has gotten progressive worse. All my TPS and TB settings are unchanged.

[Tom H]

You mention progressively worse. Then what has changed?

Has the weather changed, different gas station, etc?

Trying not to have to buy things...... Do you have a known working set of used spark plugs, caps and wires? Are you sure that all the wires including spark plug wires are tight and in place?

Sorry to ask maybe silly questions.

If all is in order, again I may have missed this, check the crank position sensor. I should have saved what the resistance should be, but worth checking it as well as making sure it's not loose.

Not much help, that's all I got so far.
Tom

[s1120]

Hey all  I found out what the problem was.... it was in fact a sensor... what one you ask?,,,,,,  ya...  well about that...…


So.. seems my fuel sensor is broke...  WHAAAA

You know...  Ive been working on cars and equipment for WAYYYY to many years to be missing this...  I think I just expect the worse...  Any way....  thank you all for your time, and help. Ill just sit over here and put on the dunce hat......yup...  im a freaken moron...   

[s1120]

I guess the silver lining here is that I got a few bolts that were pretty rusted that I cleaned and antiseezed...  I put my hands on a lot of connection that I cleaned and made sure were tight. I got some contact cleaner in some connectors..  and all and all learned a lot more about my bike.. So...  here we are. Thanks again for all the help.

[Chuck in Indiana]

My friend Ed says that even failed experiments aren't really failures.. you have learned what doesn't work.  This gave you the opportunity to do some much needed maintenance to your electrical system. <shrug>

[Guzzidad]

   I'm a little confused. Fuel sensor, you mean the low fuel sensor? How could that cause the symptoms you were having?

[antmanbee]

Count me confused too.