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HELPPP Starts (with jump leads) then revs fluctuate !!

Posted: Sat Mar 02, 2013 5:51 pm
by ROCKOZ
I've been working on it all day fiddling with my yoke, drilling the security bolt etc etc... New yoke, bars and badly cut down fairing on. Then it started. Then pissed out fuel.. I hadn't done the banjo under the fuel tank up enough...

Then after taking the plugs out, letting the fuel evaporate she starts. Runs fine for 20 mins...

Go inside, get my girlfriend, ready for a ride and it won't start.

Jump leads, van...it starts...then the revs fluctuate between 0-3k and if you rev it, it backfires and pops then goes to die...
The diag -1, 1 came up and EFI

So confused..and pissed off.

Starting to think I should've bought a VTR.

Any help??please

Posted: Sat Mar 02, 2013 7:10 pm
by fatboy
Diag 1 relates to throttle position sensor, D-Rider knows loads on this subject
Diag 1,1 may be TPS problem.
Not unusual to see Diag 1 when you switch ign on, this will change to EFI,
have a look at download manuals somewhere on here, try the search .
Griff and Lewis at Aprilia Performance are shit hot,good with advice
01827 285500

Posted: Sun Mar 03, 2013 12:59 pm
by ROCKOZ
We've tried to reset the TPS to 0. Worked fine...took it up the road, loss of power..then to keep it alive I had to keep the revs up whilst it backfired lots.
It makes no sense.....

Posted: Sun Mar 03, 2013 3:57 pm
by falcomunky
HT/coil problem? Easy to pull the plug caps away from the end of the HT leads when removing plugs...

Posted: Sun Mar 03, 2013 5:01 pm
by Dalemac
it's not going down to one cylinder is it?

Dale

Posted: Sun Mar 03, 2013 5:06 pm
by ROCKOZ
It's running on two
Could be plugs or coils but surely to make it fluctuate from 0-4k revs on it's own it must be a sensor!?
Wish I'd got a video. Its like a bloody ghost bike!

Posted: Sun Mar 03, 2013 6:37 pm
by fatboy
Check all 4 plugs,caps and leads are good.
If your plugs are black and sooty then its electrical, if the plugs look a healthy chocolate color then it may be fuel starvation, you would expect to see evidence of unburnt fuel with that amount of mis firing

Posted: Sun Mar 03, 2013 8:38 pm
by Shetland Woody
I am hopeless with electrics, but just trying to think of possibilitys. Are you sure everything is tight in the wiring mod you did, unlikely I know but......who knows :smt017

Posted: Sun Mar 03, 2013 9:25 pm
by back_marker
Check the little sensor that is attached to the bottom of the airbox and it's connection. Can't remeber exactly what it does but it completes a closed loop system so you have to disconnect it when balancing the throttle bodies. If it is not properly connected it causes similar symptoms.

If all is OK with that, also try checking all of the vacuum take off points on the other side of the throttle bodies, they shoud have a pipe (slipper clutch) on one and a blanking cap on the other. If one of those is open to the elements, the engine will not run properly.

Posted: Sun Mar 03, 2013 9:40 pm
by ROCKOZ
We unplugged it when it flooded to get at the front plugs but should've plugged back in ok.
I'll not get a chance to fiddle til the w.e now :(
Will keep you informed and any more suggestions very welcome!

Posted: Sun Mar 03, 2013 10:30 pm
by Falcopops
Since you've had the fuel pipe off, check that it isn't kinked now, restricting the fuel flow.

Posted: Mon Mar 04, 2013 6:59 am
by Aladinsaneuk
check the vacuum tubes - one is off or damaged imho

Posted: Mon Mar 04, 2013 4:55 pm
by ROCKOZ
I will check everything suggested but Aladinsane surely is a vacuum tube was pinched or off then it'd always run shit...I went out to the garage Sunday night, pressed the starter and off she went. Ran fine....(well on tickover in the garage)

:S

Posted: Mon Mar 04, 2013 5:54 pm
by Aladinsaneuk
The little buggers can dislodge very easily if loose - and can split....

Posted: Mon Mar 04, 2013 7:46 pm
by fatboy
Not thought about the vac pipes,was under the impression you would not be able to get bike started with effd vac pipe(s)
Remember looking at my g/freinds Megane,wouldnt tick over and struggled below 2000rpm...
new pipe on barometric equaliser and all good.