2002 Aprilia rsv stutter after couple of miles,then ok?

[robbocop33]

Still got this stuttering problem??(can't remember if i posted here before)Bike starts perfectly,runs for about a couple of miles then it wants to die,you have to ride the clutch at low revs to stop it stalling,it stutters slightly,giving it throttle it will accelerate ok with no stutter,then when you slow down you have to ride the clutch again to stop stalling.
This lasts for a minute or two and you really think you're not getting home,then it just clears itself and runs perfectly all day!?
I've been on bike 3 times,first time ok 2nd,3rd times it stuttered after the exact same distance of driving?
I took the precaution after previous advice of fuelling at a different station but bike is still the same.
It really does feel like a bit of dirty fuel,then it clears but doing that twice?Nah! :-)

[Onelastattempt]

You need to find out if it is a fuel system problem or an ignition problem..
Check fuel filter , is it old and dirty?
Check that all vacuum hoses are connected correctly and clear, air vent in filler cap not blocked.
Check spark plugs, coils, ht leads, disconnect everything ,clean and inspect.

[roboxm3]

Does is definitely accelerate as it should?? I had a fuel pump go on mine but it would feel like it ran nearly right a lot of the time, so it was hard to pinpoint...

As pointed out above though, check everything else fuel related and all of the little vacuum hoses that run off the TB.

[black-k1]

As I sgguested it's most likely the coils. I had a RST1000 Futura that did pretty much the exact same. Being twin plug per cylinder with a coil per plug it can be hard to track coil issues because it only takes one plug/coil to "almost work" and the cylinder fires.

[robbocop33]

Wouldn't the onboard diagnostics pick up on a coil misfire?There were no failt codes showing.I don't know how good the fault detection is with the diagnostics.

[black-k1]

I can't say that the onboard diagnostics would or should report the coil failures, only that I had almost exactly the same symptoms on my RST1000 Futura and replacement of the coils solved the problem. Coincidently, it also significantly improved the mpg/range.

[Charlie Croker mk2]

Could be fuel supply related , there is a hose that links the fuel pump to the fuel filter inside the tank and they are known to crack and give very low fuel pressure , but to inspect it you need to remove the whole assembly from the tank . Coils could be suspect but would all 4 fail at once ?

The vacuum lines at virtually 20 years old are where I would look first then battery connections . Has your bike still got the original wiring for the rectifier ? this could cause low battery voltage and symptoms like yours , but a last thought is has the bike got a aftermarket alarm system fitted ? worth checking the wiring if it has .

These gen 1 bikes are normally mega durable , report back with the fix !

[robbocop33]

I'm going to give it a full service,balance the throttle bodies and replace every vacuum hose with silicon ones while i'm in there.It's odd the bike runs great,then badly for a short period,then good again for the rest of the day.Temporary faults are a pig.
Bike has no alarm system incidentally.I'll report back once i've been in about it.Thanks for the reply.

[PorkInsider]

Is it an issue whenever you start it, or just from cold?

[Matt_E_Mulsion]

It sounds to me a bit like it is struggling in that phase when it is coming off the 'choke' / fast idle setting, somewhere between cool and normal temperature running.

Could it be related to a dicky coolant temperature sensor giving the engine/ECU a false reading and causing the bike to run too lean too soon???

[robbocop33]

PorkInsider said:

Is it an issue whenever you start it, or just from cold?

Starts perfectly everytime from cold,2 or 3 miles travel it stutters and won't idle,but wil accelerate without stuttering slightly down on power,within 2 minutes it clears itself and is fine for the rest of the journey.

[PorkInsider]

Matt_E_Mulsion said:

It sounds to me a bit like it is struggling in that phase when it is coming off the 'choke' / fast idle setting, somewhere between cool and normal temperature running.

Could it be related to a dicky coolant temperature sensor giving the engine/ECU a false reading and causing the bike to run too lean too soon???

That's what I was thinking, and OP's latest reply still points that way for me.

[Freakuk]

Does it happen when it's hot?

[P675]

Sorry if this has been answered but are you using the 'choke' on the left hand handlebar (all it does is hold the throttle on a bit). Correct starting procdure is to flick this on to enough revs to stop stalling, until COLD disappears from the dashboard then turn it off. Riding using this not-choke is usually awkward.

[robbocop33]

Freakuk said:

Does it happen when it's hot?

No.

[robbocop33]

P675 said:

Sorry if this has been answered but are you using the 'choke' on the left hand handlebar (all it does is hold the throttle on a bit). Correct starting procdure is to flick this on to enough revs to stop stalling, until COLD disappears from the dashboard then turn it off. Riding using this not-choke is usually awkward.

I've never ridden with the choke on,just fire it up with choke on,i instantly then put it half off,then within a minute or so it's ready to go with the choke off!

[robbocop33]

Matt_E_Mulsion said:

It sounds to me a bit like it is struggling in that phase when it is coming off the 'choke' / fast idle setting, somewhere between cool and normal temperature running.

Could it be related to a dicky coolant temperature sensor giving the engine/ECU a false reading and causing the bike to run too lean too soon???

I've recently been on several car tech courses and temperature sensors have gone from something that just used to be screwed into your cylinder head and told you the temp of your coolant,now they're right at the heart of modern motors and other conditions,faults can be brought on by other systems dependant on the ect.
However,the fact it doesn't happen all the time and 'clears up' slightly puts me off that route,but ofcourse,it could be intermittent in some way.

[robbocop33]

Just had a thought there,previous owner said it had an eeprom chip,can these faulter or cause glitches if they play up?I thought about replacing it with the standard one he gave me,just to rule it out?

[Krikkit]

robbocop33 said:

Matt_E_Mulsion said:

It sounds to me a bit like it is struggling in that phase when it is coming off the 'choke' / fast idle setting, somewhere between cool and normal temperature running.

Could it be related to a dicky coolant temperature sensor giving the engine/ECU a false reading and causing the bike to run too lean too soon???

I've recently been on several car tech courses and temperature sensors have gone from something that just used to be screwed into your cylinder head and told you the temp of your coolant,now they're right at the heart of modern motors and other conditions,faults can be brought on by other systems dependant on the ect.
However,the fact it doesn't happen all the time and 'clears up' slightly puts me off that route,but ofcourse,it could be intermittent in some way.

Agreed - I would expect a resistive temp sensor not to suddenly start working then stop. The ECU will also likely be clever enough to deal with open circuit faults or give a warning light (a quick google suggests it has fault-codes etc).

On how vital they are, they've been pretty crucial since the earliest fuel injection, and the tighter emissions get, the more reliant they are on accurate temp measurement, which is often why you have both oil and water or head temp.

robbocop33 said:

Just had a thought there,previous owner said it had an eeprom chip,can these faulter or cause glitches if they play up?I thought about replacing it with the standard one he gave me,just to rule it out?

In which case that'd be my first port of call!

Edited by Krikkit on Tuesday 23 November 14:24

[Matt_E_Mulsion]

robbocop33 said:

I've never ridden with the choke on,just fire it up with choke on,i instantly then put it half off,then within a minute or so it's ready to go with the choke off!

Hold on a minute, what setup has the bike got and what is the bike? I assumed that it was fuel injection as you have mentioned diagnostic fault codes, EPROM chips and throttle bodies.

Now you are saying it has a manual choke???

I'm slightly confused here...