Author Topic: mysterious and predictable engine cutting out  (Read 5938 times)

Online lazlokovacs

  • Gaggle Hero
  • *****
  • *
  • Posts: 1079
mysterious and predictable engine cutting out
« on: February 17, 2018, 07:27:16 PM »
my mates Cal Vintage... In pretty immaculate condition... has developed a strange fault.


After around three minutes of riding when started from cold it pretty much ALWAYS cuts out. Loses both cylinders at once.

Sometimes its then hard to restart. A quick roadside test showed that when it won't restart there is no spark at the plugs. (the non sparking plug worked fine on my bike)

Weird thing is the batt has plenty of juice, it turns the starter motor over beautifully... And weirder still, once the bikes warmed up it gives no trouble at all.

Any ideas?

cheers

Offline Sasquatch Jim

  • Gaggle Hero
  • *****
  • Posts: 9600
  • Sidecar - Best drive by shooting vehicle ever
Re: mysterious and predictable engine cutting out
« Reply #1 on: February 17, 2018, 07:47:36 PM »
 The bike is telling you it wants to be sold cheaply.
Sasquatch Jim        Humanoid, sort of.

Offline SED

  • Gaggle Hero
  • *****
  • *
  • *
  • Posts: 1627
Re: mysterious and predictable engine cutting out
« Reply #2 on: February 17, 2018, 08:21:00 PM »
Does it restart after a brief rest then fine?  I had an electronic ignition in my Ariel for about 5 years and it started doing this.  Never figured it out for sure, but think it was the coil.
1983 LeMans III
1981 Monza
1947 Ariel Red Hunter
1939 Ariel Red Hunter
1937 Guzzi GTV

Offline fotoguzzi

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 19931
  • vee git tooh soon oldt und too late wise -my Dad
Re: mysterious and predictable engine cutting out
« Reply #3 on: February 17, 2018, 08:28:11 PM »
my mates Cal Vintage... In pretty immaculate condition... 

Any ideas?

cheers

are the battery terminals clean and tight?

how many miles? some of the Vintages just never ran right.. some solutions were to change up the ECU for a V11 box (5M?) I have  friend who's Vintage was so bad he got a lemon law replacement NEW bike..
is there any way you could substitute another ECU?
I know it's a little off the wall answer.
MINNEAPOLIS, MN

Wildguzzi.com

Re: mysterious and predictable engine cutting out
« Reply #3 on: February 17, 2018, 08:28:11 PM »

pete roper

  • Guest
Re: mysterious and predictable engine cutting out
« Reply #4 on: February 17, 2018, 09:39:19 PM »
Sidestand switch?

Offline Huzo

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 13202
  • Location: Creswick Australia
Re: mysterious and predictable engine cutting out
« Reply #5 on: February 17, 2018, 10:39:25 PM »
Both cylinders at EXACTLY the same time ?

Offline yogidozer

  • Gaggle Hero
  • *****
  • Posts: 2920
Re: mysterious and predictable engine cutting out
« Reply #6 on: February 17, 2018, 11:17:23 PM »
are you near the Black Hills, Burkittsville, Maryland?  :shocked:



« Last Edit: February 17, 2018, 11:18:36 PM by yogidozer »

Offline LowRyter

  • Gaggle Hero
  • *****
  • *
  • *
  • Posts: 16685
  • Location: Edmond OK
Re: mysterious and predictable engine cutting out
« Reply #7 on: February 18, 2018, 12:14:33 AM »
listen for the fuel pump upon restart attempt.

then check to see if the fuses are clean and making good contact.
John L 
When life gets you down remember it's one down and the rest are up.  (1-N-23456)

Offline Motomoto

  • New Egg
  • *
  • Posts: 27
  • Location: Burkittsville, Maryland
Re: mysterious and predictable engine cutting out
« Reply #8 on: February 18, 2018, 03:01:57 AM »
My similarly spooky Burkittsville Cali was fixed by pulling away the fuse/relay assembly and finding and re-insulating a wire that was shorting against the assembly's bracket.  While in there I replaced and DeoxIT'ed the fuse and relay sockets and cleaned up the spades with 0000 steel wool.  Not a stumble since.


Offline Old Jock

  • Gaggle Hero
  • *****
  • Posts: 2643
Re: mysterious and predictable engine cutting out
« Reply #9 on: February 18, 2018, 04:08:18 AM »
Sounds like something when getting up to temperature is then failing

So just ask the question again definitely BOTH sides loose spark?

4 Spark plugs, 2 coils? I'm asking as that is what Carl Allison's diagram shows

If I'm using the correct diagram I'd look at the Power Relay and check Fuse 7, swap the relay with something else and check all the fuse contacts. Loss of power or the relay misbehaving will stop the bike dead, it supplies the injectors and coils. I'm not saying that is the fault but it's a common failure point so it's where I'd start

John 

Offline e.cleven

  • Hatchling
  • **
  • Posts: 118
  • Location: S. Minn/SW. Fl.
Re: mysterious and predictable engine cutting out
« Reply #10 on: February 18, 2018, 08:18:09 AM »
I had the same problem on a 08 Calvin. We would be going down the road just fine and all of a sudden it would quite sometime it would pick up by it's self other times not. Cleaned the fuses and replaced relays, but no enchilada.
Turned out there was a bad connection behind the relay holders.
Removed the relay block and let it hang down and pulled out the wiring.
Turned the ignition on and just kept wiggling the connectors in the harness until I could hear the fuel pump start and stop.
Squeezed the connector and put it all back and all was well for seven years, but last summer the cutout was back, so I will have do it again this spring.
I did put a V11 ECU in it and it runs like it should now.
Good luck with yours.

Earl

Offline dlapierre

  • Gosling
  • ***
  • Posts: 231
    • Habitat Farm
Re: mysterious and predictable engine cutting out
« Reply #11 on: February 18, 2018, 11:00:15 AM »
One more idea: I had he same thing happen to me on the same model bike. Turned out it was a short in the wires under the seat. Take off the seat and see if anything has worn bare or come loose from the pressure of sitting on the seat.

Online John A

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 4905
  • No way to slow down...
  • Location: Hager city ,western WI
Re: mysterious and predictable engine cutting out
« Reply #12 on: February 18, 2018, 12:47:19 PM »
Another place to check is the base of the ignition switch. The contacts could be loosing their connection. It can be removed and cleaned or replaced. It is a wear part that can be replaced . It comes as the base with about six inches of lead and its connection to the harness. You don't need to remove the switch, just gain access to the base. I'll post the part number when I get to the shop unless someone beats me to it. The most likely culprit is the sidestand kill switch as Pete said.
John
MGNOC L-471
It is easier to fool people than it is to convince them that they have been fooled-Mark Twain
99 Bassa, sidecar
02 Stone
84 V65C
15 F3S Spyder

Online lazlokovacs

  • Gaggle Hero
  • *****
  • *
  • Posts: 1079
Re: mysterious and predictable engine cutting out
« Reply #13 on: February 18, 2018, 12:48:01 PM »
Thanks guys,

Huzo - My mate says that he THINKS its both cylinders cutting out at the same time... I haven't ridden it so I can't be 100percent sure

Pete- sidestand switch has been previously welded shut, and there's nothing random about when the bike loses power..... happens after about 3mins every time!

OLDjock---- Yes, its 4 plugs 2 coils and I'm sure you have the right diagram.

Fuel pump is working fine.

I'm thinking its going to be a case of inspecting and testing all the wires...

Will start at the relays then

Anyone have a part number for a replacement relay? (or even better the non-guzzi equivalent part number)

Interestingly, my friend also says that if he opens er right up when it starts to cut out then he can kind of ride it out and the bike will keep going. Until next time he drops the revs....

head-scratching.

Online John A

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 4905
  • No way to slow down...
  • Location: Hager city ,western WI
Re: mysterious and predictable engine cutting out
« Reply #14 on: February 18, 2018, 12:52:31 PM »
Electric petcock fault?
John
MGNOC L-471
It is easier to fool people than it is to convince them that they have been fooled-Mark Twain
99 Bassa, sidecar
02 Stone
84 V65C
15 F3S Spyder

Offline Sasquatch Jim

  • Gaggle Hero
  • *****
  • Posts: 9600
  • Sidecar - Best drive by shooting vehicle ever
Re: mysterious and predictable engine cutting out
« Reply #15 on: February 18, 2018, 12:55:22 PM »
  A pilot would not stand for the sort of engine.
Sasquatch Jim        Humanoid, sort of.

Offline Huzo

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 13202
  • Location: Creswick Australia
Re: mysterious and predictable engine cutting out
« Reply #16 on: February 18, 2018, 06:45:42 PM »
Thanks guys,

Huzo - My mate says that he THINKS its both cylinders cutting out at the same time... I haven't ridden it so I can't be 100percent sure


Ok.
I would start my investigation by starting the bike and invite it to fail.
When it cuts out I would ascertain if it's on both cylinders at EXACTLY the same time.
Thinking about it a bit suggests it can't be coil, points, electronic ignition pickup or similar, because there'd be a tendency to struggle on with one cylinder firing.
It's something that serves both pots.
My MV Augusta had a feature in the ECU that supplied a fast idle for 20,000 spark cycles which translates to about 4 minutes fast idle then the brain switched the idle speed back to 1100 rpm.
Just wondering (showing my ignorance) is your bike fuel injected with ECU controlling things ?
Maybe there's a switching function that reads engine temp and giving a false command ???
You must ascertain if it's fuel or not.
You'd reckon that a fuel starvation issue or tank vent problem would not kill both at once with such suddenness.
« Last Edit: February 18, 2018, 06:54:34 PM by Huzo »

Offline Huzo

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 13202
  • Location: Creswick Australia
Re: mysterious and predictable engine cutting out
« Reply #17 on: February 18, 2018, 06:57:57 PM »
are the battery terminals clean and tight?

how many miles? some of the Vintages just never ran right.. some solutions were to change up the ECU for a V11 box (5M?) I have  friend who's Vintage was so bad he got a lemon law replacement NEW bike..
is there any way you could substitute another ECU?
I know it's a little off the wall answer.
No it's not.
Substituting a known good unit on yours and putting the suspect one on the other bike gives a non ambiguous answer.
Always a good diagnostic approach.

Offline Huzo

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 13202
  • Location: Creswick Australia
Re: mysterious and predictable engine cutting out
« Reply #18 on: February 18, 2018, 06:59:35 PM »
  A pilot would not stand for the sort of engine.
Well no...
But this bloke is not exactly thrilled to bits either !

Offline fotoguzzi

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 19931
  • vee git tooh soon oldt und too late wise -my Dad
Re: mysterious and predictable engine cutting out
« Reply #19 on: February 18, 2018, 08:11:34 PM »
are the relays Siemens? (bad) get a full set from Pyro Dan
http://dpguzzi.com/

are there fault codes stored? I think you need Guzzidiag software to read them..
MINNEAPOLIS, MN

Offline Ncdan

  • Global Moderator
  • Gaggle Hero
  • *
  • *****
  • *
  • *
  • *
  • *
  • *
  • Posts: 5878
Re: mysterious and predictable engine cutting out
« Reply #20 on: February 18, 2018, 08:22:45 PM »
I’m just throwing something out not from experience. Could the map be sent to a mapping specialist for reviewing. We have a couple of those guys on the forum.

oldbike54

  • Guest
Re: mysterious and predictable engine cutting out
« Reply #21 on: February 18, 2018, 08:28:40 PM »
 Lazlo , it is really hard to diagnose problems long distance , and doubly hard when the questions and answers are being filtered thru a third person . Any chance your friend could simply join the board so our experts can communicate directly with him ?

 Dusty

Offline Wayne Orwig

  • Gaggle Hero
  • *****
  • Posts: 13908
    • Hog Mountain weather
  • Location: Hog Mountain
Re: mysterious and predictable engine cutting out
« Reply #22 on: February 18, 2018, 08:30:03 PM »
I�m just throwing something out not from experience. Could the map be sent to a mapping specialist for reviewing. We have a couple of those guys on the forum.

Map?

Scientist have discovered that people will believe anything, if you first say "Scientists have discovered...."

Offline Kiwi_Roy

  • Gaggle Hero
  • *****
  • Posts: 9796
  • Location: New Westminster BC
Re: mysterious and predictable engine cutting out
« Reply #23 on: February 18, 2018, 09:00:06 PM »
If either the ECU relay (52) or the power relay (50) drops out the bike will stop.
A small wire wrapped around the 87 pin of each relay going to a 12 Volt lamp to chassis will indicate which relay is dropping (the ECU will cause both to drop)
The lamp will glow as long as it has power, if it goes out when the engine stops then find out why.

Chassis ----------------(12V Lamp)-----------------> 87 pin

Important Clue - The ECU relay coil is grounded through a diode the wire also grounds the Start Relay coil. Does the bike crank over after it stalls?

A bad timing sensor will cause the power relay to drop out, they have been known to fail with temperature (turns of ignition injectors and pump), the lamp on the 87 pin of that relay will tell you if that's happening.

One more thing it could be is tank suck with a blocked tank vent the vacuum prevents the pump drawing fuel out of the tank, somehow I don't think its that in this case but it's dead easy to check, just oren the fillet cap to see if you get an inrush of air and immediate restart.

http://www.thisoldtractor.com/guzzi007/schematics/2008_California_Vintage.gif
« Last Edit: February 18, 2018, 09:51:01 PM by Kiwi_Roy »
72 Eldorado
17 V7iii Special
76 Convert
Half a V9 Roamer

Moto Guzzi - making electricians out of riders since March 15 1921

Offline Zoom Zoom

  • Gaggle Hero
  • *****
  • Posts: 10519
Re: mysterious and predictable engine cutting out
« Reply #24 on: February 19, 2018, 06:09:19 AM »
Having been a victim of tank suck, I believe that it can be ruled out in this case. Tank suck is not partial to any given amount of set time. It will vary with how much fuel is in the tank. Tank suck will occur sooner on a full tank than a more empty one. Also, if the tank is then not vented, it will occur a bit further down the road.

As for a switch, I only thinking out loud here, but again, if a loose connection, why would it only happen 3 minutes into the engine running and not happen again later on? Certainly not ruling out the electrical aspect here. Just thinking it is unlikely the ignition switch or something loose. Loose would more translate to "Whenever I hit some bumps, the bike cuts out", which is not what was described here. Since there seems to be a defined pattern here, that should be a little more helpful in figuring it out.


John Henry
« Last Edit: February 19, 2018, 07:52:52 AM by Zoom Zoom »

Online lazlokovacs

  • Gaggle Hero
  • *****
  • *
  • Posts: 1079
Re: mysterious and predictable engine cutting out
« Reply #25 on: February 19, 2018, 07:49:50 AM »
Kiwi Roy-

great info

bike cranks over just fine after it stalls.....


Offline Tkelly

  • Gaggle Hero
  • *****
  • *
  • *
  • Posts: 1030
Re: mysterious and predictable engine cutting out
« Reply #26 on: February 19, 2018, 11:42:54 AM »
I had a sensor fail on a 97 Cal.

Offline Kiwi_Roy

  • Gaggle Hero
  • *****
  • Posts: 9796
  • Location: New Westminster BC
Re: mysterious and predictable engine cutting out
« Reply #27 on: February 19, 2018, 12:13:30 PM »
I took one of Carl's drawings and cut out the vital organs to illustrate how simple they are. All of the wiring you see is like a sub loom, very reliable, all it needs is a signal to go from the ignition switch via a stand relay and the kill switch. The wire going to the tach is not important for running.
The Safety diode on the Vintage must be grounded thru pin 2 for the ECU relay to close, most other Guzzis have the diode straight to negative with the interlocks in the signal from ignition switch.
The relay pins are the easiest point to access the signals, just wrap a small wire around the pin.



TKelly just mentioned a sensor, if the timing sensor goes open circuit the ECU will think the engine has stoped and drop out the power relay. These sensors are known to fail and also leak oil. They must be gapped correctly. The lamps I show will tell you if the sensor is not working the ECU lamp will be On but the Power Relay lamp will not turn on while cranking.
I think I'm the only owner that put a lamp on every relay of my first fuel injected Guzzi, I'm an electrician but I can't see electricity without some help LOL
« Last Edit: February 19, 2018, 12:32:59 PM by Kiwi_Roy »
72 Eldorado
17 V7iii Special
76 Convert
Half a V9 Roamer

Moto Guzzi - making electricians out of riders since March 15 1921

Offline fotoguzzi

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 19931
  • vee git tooh soon oldt und too late wise -my Dad
Re: mysterious and predictable engine cutting out
« Reply #28 on: February 19, 2018, 01:24:53 PM »


TKelly just mentioned a sensor, if the timing sensor goes open circuit the ECU will think the engine has stoped and drop out the power relay. These sensors are known to fail and also leak oil. They must be gapped correctly. The lamps I show will tell you if the sensor is not working the ECU lamp will be On but the Power Relay lamp will not turn on while cranking.
I think I'm the only owner that put a lamp on every relay of my first fuel injected Guzzi, I'm an electrician but I can't see electricity without some help LOL
some Spine frame had a problem with the cam sensor, the wire out of the sensor made a 90 degree turn up, when the engine warmed the signal would fail.(and the wire would be soft and flexible in the area). so wondering if it happens regularly when the engine warms up enough to affect the sensor wire?
MINNEAPOLIS, MN

Offline Kiwi_Roy

  • Gaggle Hero
  • *****
  • Posts: 9796
  • Location: New Westminster BC
Re: mysterious and predictable engine cutting out
« Reply #29 on: February 19, 2018, 02:52:51 PM »
some Spine frame had a problem with the cam sensor, the wire out of the sensor made a 90 degree turn up, when the engine warmed the signal would fail.(and the wire would be soft and flexible in the area). so wondering if it happens regularly when the engine warms up enough to affect the sensor wire?
What you say makes perfect sense but the sensor is expensive just to change on spec.
If the Power relay drops out while the ECU relay stays closed it would certainly point to the sensor, so easy to verify, so hard to persuade the owner to do a little testing
72 Eldorado
17 V7iii Special
76 Convert
Half a V9 Roamer

Moto Guzzi - making electricians out of riders since March 15 1921

***Wildguzzi Official Logo High Quality 5 Color Window Decals Back In Stock***
Shipping in USA Only. Awesome quality. Back by popular demand. All proceeds go back into the forum.
http://www.wildguzzi.com/Products/products.htm
Advertise Here
 

20 Ounce Stainless Steel Double Insulated Tumbler
Buy a quality tumbler and support the forum at the same time!
Better than a YETI! BPA and Lead free.
Advertise Here