Problems related or separate ones?? misses, limp mode, rev skips... argh *vid

[jfryjfry]

The summary of my saga is as follows:

Bike has pcIII, exhaust, no smog stuff... all done before i got bike. I put 10k miles on it and never touched anything other than oil.
Bike has ALWAYS had a tendency to die if I chop throttle quick with clutch in coming to a stop, so i've developed the habit of letting throttle close a bit slower than just chopping it and no problem. ALWAYS idled fine after that. if it did die (because i chopped the throttle with clutch in), i just restarted.

Cut to 4 months ago. 40 mile ride home from work, mostly freeway. all good until after about 5 minutes of city driving, getting close to house and i was at a stop and the bike just died. wierd. restarted fine. did it again at the next stop. was idling for a bit and then died.

made it home no prob, the next day started it up and it quickly started the same behavior idling in garage. only now it would miss miss miss then die. sometimes quickly, sometimes 30 seconds between.

I disconnected pcIII with no change. ultimately found a vacuum line had come off. one of the tiny ones on the left side off throttle bodies to air box. i believe it was the map sensor. regardless, i was already into the bike so i pulled the valve covers and checked valve clearances. they were fine.

bike sat for 2 months waiting for parts and then out of town. finally finished it and tried to start it about 3 weeks ago. nothing. checked and checked and finally, for whatever reason, unhooked the power commander again and it fired up. for kicks, i hooked pcIII back up and it fired and ran great. wierd.

from then on it was fine (well, it wasn't initially - one of the cam chain tensioners had bled down and was making a huge racket. it took me a while to figure that one out. but once it idled for 5-10 seconds all was good). I didn't have a chance to ride it, but it idled great, with no issues.

yesterday i finally get to ride the bike. starts great and i'm excited after 4 months of no aprilia. after about 15 minutes of city driving i get on the freeway. i soon notice a hesitation that seems like it's running out of gas. i figured gas might have gone bad.

i get off freeway and start looking for gas. problem gets worse. missing, won't go full throttle. finally the red triangle and ecu warning come on and it's in limp mode - won't rev over 4.2k and nothing over 1/4 throttle. fresh tank of gas changes nothing.

get home, try to pull codes by holding lap button in for 30 seconds, turn ignition on, keep holding. after 20 seconds or so the "ECU" letters come up (red triangle has been illuminated the whole time as i never started the bike).
I turn off and back on and wait a minute to see if the ECU comes on naturally after so long and it does not. so no codes were given but the ECU came on.

I disconnect the PCIII and start the bike and immediately the triangle goes away and it seems fine. I take it to the store, 1.5 miles away. at first it's ok but still has a bit of a miss here and there but by the time i get there and the whole ride back, it's fine.

I'm really stumped.

I pulled the pcIII out of the bike to send back for evaluation ($30) but wanted to check and see if i could access it with my computer and see any problems (i have never done it before.) didn't realize it has to be in the bike running or you have to have a 9v power cable.

Have I fixed my problem? is it the powercommander??? i would have been certain of it as when i disconnected it it seems to run great but it initially had a few misses before clearing up.

I started it this morning and saw a wierd blip on the tach that i also hear. if i rev it kind of slower it's not there. super fast and it's not there either. but med speed it has a wierd skip from like 2000 up to 2500. a few times the motor made a wierd knock at that point too, like it had missed. (same noise i'll hear when starting it sometimes when it is a bit hesitant to start immediately).

here is a vid:



what the heck???

The only good/interesting thing i've noticed is w/out the pciii hooked up, it comes to idle a little slower when throttle is chopped, meaning i probably won't have the issue of it dying like I used to have (for the past 5 years)

[jfryjfry]

Anyone? Amurai? noel the curmudgeon??

[amauri]

1-) connect AXONE and read error codes
2-) test charging system
3-) test fuel pressure

[jfryjfry]

don't have the old axone, charging system seems to be fine and fuel pressure seems fine too.

none of the problems seem to indicate a problem with either of the last two options, and certainly removing the pciii and getting a better running condition doesn't indicate either.

I certainly can test those two, but was hoping for some ideas that might account for the symptoms specifically.

(eg faulty oil pressure switch, etc etc)

[amauri]

Your symptoms are very much related to low voltage or low fuel pressure.
Don't guess and gamble with what you think "seems" fine, you'll only waste time and money.
Diagnose it properly, there are many shops/people near you who have an AXONE.

[platypus]

This must be the season for this problem? I just had similar symptoms today also - missing while powering on between 2 and 5K rpm with a limit of 5K. Even though I installed a new stator last summer, I'm going to check that first off. Then the fuel pump. I don't have a fuel pressure testing setup, but that might be the third thing I would try. Getting the Ape to an Axone is a little more difficult.

[Galaxian]

Proper diagnostics will save you time and money in the long run.

Regarding this bit: "I disconnect the PCIII and start the bike and immediately the triangle goes away and it seems fine. I take it to the store, 1.5 miles away. at first it's ok but still has a bit of a miss here and there but by the time i get there and the whole ride back, it's fine.".

Make sure your Power Commander is grounded to the battery and not the chassis. Failing to do so can cause problems.

[jfryjfry]

yeah, pc is grounded to battery. I will say that a loose/intermitent connection involving the pc could be an issue. i've looked at the connections and they SEEM to be fine, but i don't know how to test if there is a good connection to the injectors.

And yes, i am trying to do proper diagnosis. That doesn't mean checking tire pressure and chain adjustment.
for example, when it runs like a raped ape at full throttle, but has a funny skip at part throttle from 2k-2.5k, i doubt it is a fuel pressure issue. Maybe I'm wrong -- i'd love to be enlightened if it could have adequate fuel pressure under what seems to be the most demanding situation but not adequate in a low-demand situation.

of course it could be charging or fuel pressure and if they were a quick check, i'd do it for fun. but since i'd have to rig up a system to check the pressure or cut and resolder stator wires, it's not a quick job.

I'm not trying to come up with reasons not to do proper diagnosis. I just don't want to waste time testing stuff that likely isn't a problem.

Just hoping someone might have had similar issues and be able to share what was causing their symptoms OR could hypothesize and give me something to check that they think could cause these specific problems.

[Tdawg]

1-) connect AXONE and read error codes
2-) test charging system
3-) test fuel pressure

What year is the bike? On a 04R 3 small items did very stranges things...temp sensor, oil sensor, and oddly radiator cap... Stumbling, instant loss of revs, etc
Those items were masked by low voltage issues, eventually requiring a new stator, rectalfrier, and battery (to be safe)

[jfryjfry]

which temp sensor?

curious how a malfunctioning radiator cap would cause anything other than overheating (and then maybe problems coming from the overheating condition)??

when you say these problems were masked by low voltage issues, do you mean that the stator went bad, and hid the fact that there were other problems besides the stator?

[amauri]

The colant temp sensor is known to fail on the early 04 RSV with the blue Bosch sensor.
The ECU monitors the engine temp sensor and if oveheating is detected (even if false) cuts engine power and RPMs.

[Galaxian]

Basic problems like charging systems issues or low fuel pressure can propagate a lot of symptoms that may not seem to point back to those problems. This is where experience comes in and Amauri has a lot of it...

But since we're speculating...

"for example, when it runs like a raped ape at full throttle, but has a funny skip at part throttle from 2k-2.5k"

This implies that the problem is related to throttle position and not engine speed... Assuming of course sufficient fuel supply and no other electrical gremlins are present.

A basic test of the TPS could be conducted with a decent meter, to check for 'spiking' due to a wonky/worn TPS and that the sensor is within specs.

Even if you forgo testing and just throw parts at it, get lucky and 'fix' the problem, you'd still need the services of someone with an Axone or Navigator to make the bike run right after replacing the TPS.

However, without the right tools and proper troubleshooting, pretty well anything you do to address the problem is guesswork.

We're just trying to save you time, money and grief.

If you were in my area, I'd have you run it by my place.

[jfryjfry]

i really appreciate the help and speculation. and I have no doubt that amauri has a lot of experience.

And he might normally have customers who don't know how to describe the difference between a motor that isn't turning over and one that is but isn't firing.

But looking at the symptoms, i can't imagine how, for ex., low fuel pressure would cause an engine stumble off idle at only a med throttle application.

this is why i am asking here - perhaps there is something wierd on our bikes that could cause it.

the tps is a good candidate, and i will check the voltage coming out of it.
In fact, I'm a little embarassed I hadn't thought of it.
Thanks for taking the time -- i'll report back.

and yeah, i'll have to find someone with a nav or axone close by...

[norcolmille]

i really appreciate the help and speculation. and I have no doubt that amauri has a lot of experience.

And he might normally have customers who don't know how to describe the difference between a motor that isn't turning over and one that is but isn't firing.

But looking at the symptoms, i can't imagine how, for ex., low fuel pressure would cause an engine stumble off idle at only a med throttle application.

this is why i am asking here - perhaps there is something wierd on our bikes that could cause it.

the tps is a good candidate, and i will check the voltage coming out of it.
In fact, I'm a little embarassed I hadn't thought of it.
Thanks for taking the time -- i'll report back.

and yeah, i'll have to find someone with a nav or axone close by...

I live in Colorado - and lack experienced shops like AF1 amd Amauri. . And my experience is I end up spending more $$ and time -to resolve a problem.I would welcome the chance to easily ride or trailer my my bike -with intermittent problems to an expert like Amauri

[jfryjfry]

Still no luck... tps checks out -- within spec and smooth readings across range.
Pulled fuel pump out and everything is seems fine. There was some glue that must have come off of something (silicone) and a few bits of debris but the sock was virtually pristine and the hoses look great.

I guess to restate a question that might lead to my problem briefly, what would cause the tach to jump from 2-2.5k with the motor often seeming to miss during the jump, but only with moderate throttle? doesn't do it if you go slow or even moderately quick, as shown in the video.

maybe whatever is causing that is causing my other issues...