Update on gen 1 2002aprilia mille intermitt stalling problem
Discussion
So,first ride after trying to sort out this stalling problem,and it's still stalling!!2 miles away from the house and i felt the revs die going through a 20mph zone(as usual),i have to keep slipping the clutch and keep the revs up to ride it,it only lasts about a mile then it 'always' clears itself??
It never effects further up the rev range,it pulls perfectly!
So far i have replaced the plugs,put on used coils,replaced vacuum lines and vacuum check valve,throttle bodies are back to base settings,new throttle body mounting rubbers,new fuel lines,new fuel filter and teabag filter,new fuel pump,fresh fuel,cleaned injectors,cleared tank breather pipes,cleaned and oiled k&n air filter,but it still stalls??
It never effects further up the rev range,it pulls perfectly!
So far i have replaced the plugs,put on used coils,replaced vacuum lines and vacuum check valve,throttle bodies are back to base settings,new throttle body mounting rubbers,new fuel lines,new fuel filter and teabag filter,new fuel pump,fresh fuel,cleaned injectors,cleared tank breather pipes,cleaned and oiled k&n air filter,but it still stalls??
You say 'throttle bodies are back to base settings' by that do you include the TPS? because I had a similar running issue with my 916 that was correctly setup but started behaving badly. Turns out one of the 2 screws holding the TPS to the throttle body had broken off (inside so still visually in place) and it was causing the TPS to 'flex' causing poor low speed running and stalling, seemed OK at higher speeds.
I don't know anything about Aprilia TPS setup but on the old Ducati it is very sensitive especially, it would seem, at small throttle openings.
I don't know anything about Aprilia TPS setup but on the old Ducati it is very sensitive especially, it would seem, at small throttle openings.
Funny you should mention the tps,a few weeks ago when i started trying to get to the hub of this issue i put the bike into diagnostic mode,it showed tps at 1,so set it to 0.
Next day i rode it it played up again,put it into diag mode again and wtf,it was at '1' again ??
Tps mounting bolts were definetly tightened and after tightening tps nuts diag still showed '0'.(sometimes tightening nuts can put reading on dash off again as its so sensitive)
Next day i rode it it played up again,put it into diag mode again and wtf,it was at '1' again ??
Tps mounting bolts were definetly tightened and after tightening tps nuts diag still showed '0'.(sometimes tightening nuts can put reading on dash off again as its so sensitive)
Interesting, as above I don't know how Aprilia do it, on old Ducatis you need to set a specific voltage (150mv) on a fully closed throttle rather than just set to zero, I don't know how much the difference between '0' and '1' is on the Aprilia but a very small movement makes a big difference on the Ducati (voltage runs from 150mv closed to 5v open).
One thing I have noticed is that if I leave both butterfly valves attached and set it will sometimes not consistently fully close the throttle, making the set point vary when trying to read it. To this end, some disconnect the rear TB from the linkage to ensure that the front closes and is not held by the rear not fully closing but I find it better/more consistent to slightly open the rear butterfly valve, ensuring that the full force of the closing springs works on the front TB (which is where the TPS is fitted) and that the front is definitely closed with a 150mv reading every time the throttle is snapped shut.
Bike definitely runs better if the setting is spot-on, 2 or 3mv affects the running and when the screw broke it was up to 20mv out. It's easy enough to sync the rear again afterwards, properly set-up it fuels cleanly and behaves immaculately on/off the throttle.
Also have seen where the plate in the butterfly valve can slightly move on it's shaft, thereby causing it to catch in the TB, again this is a Ducati thing and Aprilia maybe different? but by loosening the fixing screws on the spindle there is a small amount of adjustment (play) that enables you to centre it it.
Could also be the TPS breaking down?
One thing I have noticed is that if I leave both butterfly valves attached and set it will sometimes not consistently fully close the throttle, making the set point vary when trying to read it. To this end, some disconnect the rear TB from the linkage to ensure that the front closes and is not held by the rear not fully closing but I find it better/more consistent to slightly open the rear butterfly valve, ensuring that the full force of the closing springs works on the front TB (which is where the TPS is fitted) and that the front is definitely closed with a 150mv reading every time the throttle is snapped shut.
Bike definitely runs better if the setting is spot-on, 2 or 3mv affects the running and when the screw broke it was up to 20mv out. It's easy enough to sync the rear again afterwards, properly set-up it fuels cleanly and behaves immaculately on/off the throttle.
Also have seen where the plate in the butterfly valve can slightly move on it's shaft, thereby causing it to catch in the TB, again this is a Ducati thing and Aprilia maybe different? but by loosening the fixing screws on the spindle there is a small amount of adjustment (play) that enables you to centre it it.
Could also be the TPS breaking down?
Replace the tps sensor, it sounds like the wiper circuit is failing and sending a varying voltage. And it’s faulty at the low end of the sweeping zone hence why no issues at higher throttle positions.
You can reset it until the cows come home, you need a new unit….
There’s a way to confirm it with a multi meter if you know what pin on the ecu the wiper wire goes to…. Simply connect to the pin and ground and set to the 20vdc range. If you see the voltage fluctuating with no throttle application that’s your problem
You can reset it until the cows come home, you need a new unit….
There’s a way to confirm it with a multi meter if you know what pin on the ecu the wiper wire goes to…. Simply connect to the pin and ground and set to the 20vdc range. If you see the voltage fluctuating with no throttle application that’s your problem
OutInTheShed said:
Can you get a live read out of what the ECU thinks the TPS is saying?
Other things to check might include
Fuel system pressure
Fuel system clean
Injector clean/calibration.
Manifold vacuum
Crank position sensor.
I have scan tools,oscilloscopes etc but car related stuff.Bike has onboard diagnosis mode but it's 'very' basic,and currently shows no faults.Other things to check might include
Fuel system pressure
Fuel system clean
Injector clean/calibration.
Manifold vacuum
Crank position sensor.
All vacuum hoses have been renewed,new vacuum check valve,injectors cleaned,new fuel pump and filters,new fuel hoses,new plugs and coils,tank breather hoses cleared.
Crank position sensor,mmm,bike 'always' starts from cold,'always' is perfect above 3k,'always' fires back up when the stalling occurs,and 'always' clears itself after the fault occurs.
I never get stranded on the bike,when the fault iccurs i just slip the clutch,keep the revs up in 20mph zones,roundabouts etc.
Waynester said:
I have a Gen 2 that (sometimes) cuts out when blipping the throttle going down the gears.
Maybe worth calling AP Workshops for advice?
I've been talking to them on Facebook and on the phone,but i'm at the other end of the country or i'd go there :-)Maybe worth calling AP Workshops for advice?
And in answer to a previous suggestion i don't think gen 1,s have a stepper motor.
robbocop33 said:
I have scan tools,oscilloscopes etc but car related stuff.Bike has onboard diagnosis mode but it's 'very' basic,and currently shows no faults.
All vacuum hoses have been renewed,new vacuum check valve,injectors cleaned,new fuel pump and filters,new fuel hoses,new plugs and coils,tank breather hoses cleared.
Crank position sensor,mmm,bike 'always' starts from cold,'always' is perfect above 3k,'always' fires back up when the stalling occurs,and 'always' clears itself after the fault occurs.
I never get stranded on the bike,when the fault iccurs i just slip the clutch,keep the revs up in 20mph zones,roundabouts etc.
When you've checked all the plausible causes and not cured it, you can either check them all again, or work down the less plausible causes.All vacuum hoses have been renewed,new vacuum check valve,injectors cleaned,new fuel pump and filters,new fuel hoses,new plugs and coils,tank breather hoses cleared.
Crank position sensor,mmm,bike 'always' starts from cold,'always' is perfect above 3k,'always' fires back up when the stalling occurs,and 'always' clears itself after the fault occurs.
I never get stranded on the bike,when the fault iccurs i just slip the clutch,keep the revs up in 20mph zones,roundabouts etc.
My view is that these things are operating at very sensitive levels at small throttle openings, so it doesn't take much to mess it up.
If the crank sensor is 'iffy' it may work better at faster engine speeds.
A small vacuum leak on on cylinder will mess things up.
Any of the sensors (temperature, airbox pressure (if it has that?), throttle pos'n.... are there others?) being intermittent might cause the problem.
If it's like some Ducatis, one thing to check is the grounding of the ECU, which may rely on mounting bolts rather than wiring.
You can get some bizarre knock-on effects with EFI.
A nearly-blocked fuel filter can load the pump and drag the alternator volts down.
A tired fuel pump can seize or slow when hot or the volts drop.
Do both plugs look the same healthy colour?
OutInTheShed said:
When you've checked all the plausible causes and not cured it, you can either check them all again, or work down the less plausible causes.
My view is that these things are operating at very sensitive levels at small throttle openings, so it doesn't take much to mess it up.
If the crank sensor is 'iffy' it may work better at faster engine speeds.
A small vacuum leak on on cylinder will mess things up.
Any of the sensors (temperature, airbox pressure (if it has that?), throttle pos'n.... are there others?) being intermittent might cause the problem.
If it's like some Ducatis, one thing to check is the grounding of the ECU, which may rely on mounting bolts rather than wiring.
You can get some bizarre knock-on effects with EFI.
A nearly-blocked fuel filter can load the pump and drag the alternator volts down.
A tired fuel pump can seize or slow when hot or the volts drop.
Do both plugs look the same healthy colour?
Hi,it's two plugs per head and all 4 looked fine!As you you say any of the sensors can gave dicky moments.I've just been doing something i never usyally do,throw parts at it! :-)My view is that these things are operating at very sensitive levels at small throttle openings, so it doesn't take much to mess it up.
If the crank sensor is 'iffy' it may work better at faster engine speeds.
A small vacuum leak on on cylinder will mess things up.
Any of the sensors (temperature, airbox pressure (if it has that?), throttle pos'n.... are there others?) being intermittent might cause the problem.
If it's like some Ducatis, one thing to check is the grounding of the ECU, which may rely on mounting bolts rather than wiring.
You can get some bizarre knock-on effects with EFI.
A nearly-blocked fuel filter can load the pump and drag the alternator volts down.
A tired fuel pump can seize or slow when hot or the volts drop.
Do both plugs look the same healthy colour?
All the little sensors are cheap enough to pick up.As i said i've overhauled the fuel system,new pump,filters,cleaned injectors etc to rule that out.The fact it only does it at 3k or less i thought would have narrowed it dowln for me,but nope!
Vacuum hoses were my first thought away back,replaced them all with new lines.
Waynester said:
I have a Gen 2 that (sometimes) cuts out when blipping the throttle going down the gears.
Maybe worth calling AP Workshops for advice?
Ap workshops are saying it definetly by the sounds of it needs the co levels set and the throttle bodies balanced,a general tune up.Maybe worth calling AP Workshops for advice?
Yet my local place who has a dyno says they won't do it,as he said i could spend 2 or 3 hours labour to him to set it up,yet he says there's a possibility he could send me away and it still stalls??
I'm kind of stuck,other local main dealer the owner is a t
t,killed 3 women in his lifetime and got away with it all,so i swerve them on principal.I think there's a fairly standard base setting for the co adjustment which I'm sure someone on an rsv forum will be able to give you or AP workshops - but this doesn't sound like the problem to me
maybe when you replaced the tps you disturbed a bit of shonky wiring that has resettled back into it's old ways?
maybe when you replaced the tps you disturbed a bit of shonky wiring that has resettled back into it's old ways?
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