Jackal will not rev?

I’m posting here as the webmaster is on holiday for 2 weeks and can’t upgrade me to post on the tech forum until he returns. That’s not a complaint, everyone is entitled to hols… it’s just that I need some help before then.
Bike is a 2001 Jackal recently bought as a non-runner. I got it running by removing the immobiliser and sorting one or two other issues. Problem is that although it starts easily, and ticks over nicely it misfires badly when I try to rev it.
So what have I looked at?

  1. cam position sensor has been removed cleaned and replaced. No obvious fault apparant. But the price of a new one is a bit much unless I know for sure that’s the problem.
  2. Fuel filter changed as it was possible to get it to rev a bit by turning the ignition on and off a few times before pressing start button. Like it was building pressure up? I thought the filter might be blocked but a new filter didn’t make any difference. I also put a pressure gauge in the line and got a good 40psi. So it’s not a fuel issue.
  3. Relays have been swapped round with no apparant improvement.
  4. disconnected and measured the resistance of the air and oil temp sensors. The Air read 2.7K and the oil 1.7K which I thought a bit low (even for a slightly warm engine. Both should be 3K at 25C) so I disconnected it from circuit as I read somewhere that the ECU would default to some base setting. It revs a little bit better now but still misfires. and will still almost die sometimes.

I’ve read as much as I can find about the 15M ECU, but nothing about simple fault finding.
There is some info about regarding attatching a diagnostic light to a connector. Which one is it and what do I connect to where.

Any help much appreciated, I don’t like to be beaten…

Sorry about the delay buddy I will move this to tech for you

could be as simple as needing new plugs

blocked fuel tank breather?
I’ve just replaced my Jackal’s crank sensor with one for a Fiat, details in the OEM alternatives section, I found one for £36 inc p&p…
I also had a problem of a loose fitting plug cap! Check the bullet connectors in the spare yard of wiring between the alternator to regulator. Mine were badly corroded, as was one of the wires. Chop to appropriate length and replace with waterproof connector.

TPS maybe? Harley ones can be used as an alternative and are much cheaper.

of course, it could just need the tps moving a smidgeon and the throttle bodies balancing! There are good instructions for these in the tech sections here, at wildgoose etc etc. easy to wire in a plug for a voltmeter to read tps levels. If it’s misbehaving, somewhere ( on V11lemans.com?) I’ve seen instructions to drill a tiny hole in the right spot on the tps and clean corrosion out before resealing it… cheaper again! I could look later, probably, for these articles if you can’t find them…

the socket for a fault reader MAY be the one strapped away around frame tube next fuel pump, you would need to know which connections to make as it’s not made up on the Jackal. Trust us to get the budget model…McFuzzi2013-07-13 07:39:50

Looking at thishttp://wildguzzi.com/forum/index.php?topic=62157.0 it would appear to be an emergency measure to clean the tps, if it’s faulty. My Jackal is coming up to 50k now, 13 years of age, so it may be worth me getting the Harley one. Anyone else here have a life expectancy idea for them, mounted under the TB, used in all weathers in a salty country?
I spoke with a pleasant guy at the Farmyard party who’s replaced his with the Harley TPS and said he thinks he gets slightly less mpg since.
That would tally with this which also gives a way to test the tps with a vdsts and laptop. McFuzzi2013-07-13 12:56:37

have you tried contacting the previous owner in the logbook ?
he might be able to tell you
especially if he or she has offloaded it due to a major fault
other option is how old is the fuel in the tank
it goes off very quickly
and is the air filter clean ?rapheal glynn2013-07-13 19:13:33

can the original poster see any of this? if he as not got his upgrade yet, ( or am I thick )

I can get onto the thread thanks.
Thanks for all the suggestions. Went out for a ride yesterday to get away from problems…

Plugs are fine,
plug caps are fine,
wiring has been gone through twice,
Petrol is new,
Fuel tank breather fine
Awaiting logbook from Swansea
That it starts and ticks over fine must point to something eh??
I’m thinking TPS needs checking next
Keep the suggestions coming!

Blocked or crap in the fuel filter, had to swap all the filters on the bikes this year due to crap in the fuel
V11 Le Mans/V1000 and the 535 yam

See number 2 in original post. Filter changed but no improvement.
What an awkward job!

have you had the injectors out and looked at how they are working?

if they are not spraying a nice fine mist, but dribbling like an old bloke, it will give those symptoms

Ah - dose of injector cleaner in the tank? I was advised to do this occasionally for the car - virtually chuck the whole bottle in just before the next fill-up.

Checked out the Throttle position sensor (TPS) today.
You have to strip a bit of the insulation back on the three wires. I did it next to the connector at the throttle end, and hooked on a couple of small croc clips
The wire colours are as per the factory diagram, but the connections shown to the TPS internals are not correct.
The correct details are:-

Yellow = 5v
violet = 0v
Black/violet = Sense wire

I measured violet to violet/black:-

119mv on tickover position. Thats way off, so I followed the book and reset it all.
Got 147mv throttle fully shut.
adjusted stop to 374mv etc…
Sadly it wouldn’t run at all after that, the stops do seem to be screwed in much farther.
Took some more measurements which gave reasonably progressive readings in small steps of the throttle up to
Half throttle at approx 1v
It then went down to 600mv just after half throttle. back up to 1.2v for a bit and then progressive again up to
full throttle at approx 1.6v
Sounds a bit wrong to me…

And another line of thinking:-
So if tickover is supposed to be 3.1 degrees throttle opening giving 378mv from the TPS, a linear potentiometer would then give 3.78v at 31 degrees.
Full throttle at 84 degrees would be 10.24v which it can’t be 'cos the control voltage is 5v.

Conclusion:- Whilst the potentiometer inside it may be logarithmic (or some other non-linear progression), the TPS is suspect. Where’s the best place to get a replacement? Anyone bought one recently?

If you’ve followed the above and can see any flaws in the reasoning…

PS Thanks IANBOYDSENIOR, I’ll check the injectors tomorrow

Sounds like it’s knacked. I agree it should be linear, I would have thought (but what do I know) ~ if it helps dodgy TPS is known to cause havoc with cars that have them as well, often it’s the potentiometer track has worn out or broken or just bad contact. Or might have corrosion in there, not sure how well weather-proofed these things are.

It doesn’t follow that the maximum is some multiple of the minimum. All we can be certain of is that the total range is limited to being between 0 and 5.

I can’t get this link to work, try copy & paste into your browser.

OEM section has details of the Harley tps, or you can get a genuine part from gutsibits for £120.McFuzzi2013-07-15 22:53:13

I found the article at


Jeff explains that it’s a dual slope linear model.

Have you measured battery voltage? A weak battery can give these symptoms on an injected model.