V11 SPORT 2003 electrics fault " aggh!! help!"

HI. Iv,e encountered an intermitent electrical problem, which have been getting progresively worse, and hapening more often
it starts ok, runs for a few minuites & stops & will not re-start, after about 1 +1/2 hours it will re-start & then stop after a few minuites again. Its a total fail, so its not the coils. and fuses all ok. diode was replaced “the right way round”
i,ve changed relays, part rewired it, replaced regulator. battery. plugs. thought the tdc sensor my be faulty but unlikely cant trace the fault, theres no reliable guzzi dealer in west cornwall.
i would appriciate any advice & suggestions.
i,m hoping its not the ecu, but i am leaning towards that possibility.
Tony W-H

It sounds like you need someone who can plug their computer into your system.
Where do you live?

When it stops and you try to restart is it cranking? is the fuel pump priming? have you got idiot lights?

hi Ian.
yes i know i need to plug into a computer. iv,e been looking to buy one. but they are about £400 so iv,e been told, i’m looking for a used one.
i live in south west cornwall.
engine cranks, fuel pump primes and produces preasure. really stumped.

Have you changed the fuel filter?Â

What does ‘diode was replaced “the right way round”’ mean?

Sounds like it’s temperature related, (will start and run when cold but not after warmed up for a few minutes, then needs a long time to go cold again) how about the temp sensor(s)?

There is / was a bit of an issue where corrosion between sensor and engine prevents sensor getting a true reading of temp, can’t remember which model but may be something like that.


quote: thought the tdc sensor my be faulty but unlikely
What makes you eliminate the crank position sensor?
Is your machine fitted with a diagnostic led system? It might help point you towards the culprit if so. Another reasonably cheap option rather than a full blown diagnostics system is GuzziDiag. The software is free and the cables are about £30. Before you buy them, worth checking the V11 is covered ( should be ) in GuzziDiag and buy the Lonelec ones!

Now if you had come on the MMT, Â you could have plugged my GuzziDiag into the machine… :unamused: Â

Could ave taken a while to reach you tho Gav… :laughing:

Don’t know if this will help but, I’ve got an Alfa 147 and had exactly the same symptoms as you’re describing. Called up my local Alfa specialist and described the problem and without hesitation he said it was the crankshaft position sensor. They get warm and fail, cool down and it works, until they die totally, only solution is to replace the sensor, swine of a job on the Alfa don’t imagine it would be as bad on the Guzzi.

The first thing I would do is find out if it’s an ignition fault or a fuel fault this reduces the culprits by half, get yourself a spark tester which plugs in line at the plug cap, when you have your none start situation crank it and you will see if the tester is flashing, if it is then forget the electrics and check fuel systems Â

Ah, but it was a human virus that bogged him down on the way up. The bike made Gloucester way before TWH turned home with severe manflu.

I concur with the crank position sensor being the likely prob if not a fuel one. My 1100 Sportie exhibited a similar failure mode.
Runs for a bit, heats up, breaks down bike stops, cools down, restarts, heats up, breaks down etc etc etc.

Spark is erratic to say the least. What fooled me is the spark occurs but not necessarily consistent. Watch the self diag does actually point to the sensor. Mine was ‘by exception’ as the manual classes it; Luigi speak for - “work it out yersel, foolish Scottish person”.Â

I know dealers are few and far between but we have a local bloke(Tony Botto) who has all the diagnostic kit for all bikes.
He is no use to you (he lives in Didcot) but you wmay have someone similer near you.

Temperature sensors would probably just affect fueling, not cause a non start.
Check that crank and cam sensors look okay, not swollen/cracked/contaminated. Unplug and check resistance when you have a non start. If you have access to an automotive oscilloscope you could check if they’re giving a signal when cranking.
Can’t remember what the resistance should be. I had problems with a cam sensor that were intermittent, but not temperature related, so can take time to track down. Â

Resistance should be 600 ohms (+ - 100)

I think!

Phase sensor:-
These blokes stock them…
680 ohms in the Sportie one.Â

I changed my crank sensor when I had similar problems - I was never convinced that it was faulty, but it was a process of elimination. Apparently the sensor can be trouble though. Electrics eh?

thank you all for advise…
all very helpfull. got plenty to investigate. again many thanks. i will keep you informed.
Tony W-H

Tony send me PM for this but isn’t what I was asking (sorry my fault I have a bad habit of assuming everyone else is on the same wavelength as me)

What I meant was, who replaced diode wrong way round, and why, and was electrics turned on while it was wrong way round, and if so can we be sure that didn’t damage something, that kind of stuff

i have had fuel pumps that spin but create no pressure .Â

i’ve also had cam sensors that show the correct reading but are u/s.