Experiences of a PCV with Autotune on a 2004 VFR800

[kaldek]

Hey GPM, I'm feeling a bit like we're the pioneers mate, forging a path for others to follow once all the gremlins are sorted! :cheerleader:

Yeah, stick with it boys :biggrin:

If you like what we're doing now, just wait for when I buy the Supercharger kit. I'm even going to do videos!

[coderighter]

Great write-up!

I wish I was as good at getting stuff out of my head and onto "paper".

If you want to try the vacuum switch, let me know and I'll hook you up. It makes a big difference if you do a lot of round town riding, not so much if you do mostly highway.

I wouldn't mind giving the vacuum switch a shot - sadly I have 0 experience with such things so while the theory works in my head I don't know how to translate that into practice (or for that matter, exactly what sort of parts I need to make it all work!). Hence the effort vs frustration tip up.

This might be a silly question, but does the Aussie model have EVAP?

[kaldek]

Great write-up!

I wish I was as good at getting stuff out of my head and onto "paper".

If you want to try the vacuum switch, let me know and I'll hook you up. It makes a big difference if you do a lot of round town riding, not so much if you do mostly highway.

I wouldn't mind giving the vacuum switch a shot - sadly I have 0 experience with such things so while the theory works in my head I don't know how to translate that into practice (or for that matter, exactly what sort of parts I need to make it all work!). Hence the effort vs frustration tip up.

This might be a silly question, but does the Aussie model have EVAP?

The '02-'05 models definitely don't. Someone said though that after '06 they were standardised worldwide and they all have EVAP now. Not sure who that was or if it is true.

I just wish the Aussie models had ABS. They never offered it here. :cheerleader:

[kaldek]

Folks, GPM has confirmed he also runs the 1.4.0 firmware but also that his model came with the 1.3.0 firmware. My unit came with firmware 1.2.0, and the temperature sensor function did not work.

You will need to have either firmware 1.3.0 or 1.4.0 for the temperature sensor functions to work. GPM reported no problems with his firmware upgrade, so you also may not have a problem with your upgrade.

[coderighter]

Folks, GPM has confirmed he also runs the 1.4.0 firmware but also that his model came with the 1.3.0 firmware. My unit came with firmware 1.2.0, and the temperature sensor function did not work.

You will need to have either firmware 1.3.0 or 1.4.0 for the temperature sensor functions to work. GPM reported no problems with his firmware upgrade, so you also may not have a problem with your upgrade.

My PCV, which i installed May '09, had 1.2.0 firmware also and the temp didn't work either. Sorry, so long ago, I forgot all about it. You must have gotten real old stock?!?!

[coderighter]

Great write-up!

I wish I was as good at getting stuff out of my head and onto "paper".

If you want to try the vacuum switch, let me know and I'll hook you up. It makes a big difference if you do a lot of round town riding, not so much if you do mostly highway.

I wouldn't mind giving the vacuum switch a shot - sadly I have 0 experience with such things so while the theory works in my head I don't know how to translate that into practice (or for that matter, exactly what sort of parts I need to make it all work!). Hence the effort vs frustration tip up.

This might be a silly question, but does the Aussie model have EVAP?

The '02-'05 models definitely don't. Someone said though that after '06 they were standardised worldwide and they all have EVAP now. Not sure who that was or if it is true.

I just wish the Aussie models had ABS. They never offered it here. :cheerleader:

So..... What do you have where EVAP would be connected, because that's the source for the vacuum switch.

vacuum dia

[kaldek]

My PCV, which i installed May '09, had 1.2.0 firmware also and the temp didn't work either. Sorry, so long ago, I forgot all about it. You must have gotten real old stock?!?!

Yeah, we're a long way for America over here mate. They would have imported them in bulk and maybe don't sell so many for the VFR. Coulda been on the shelf for aaages!

[Guest GPM]

Folks, GPM has confirmed he also runs the 1.4.0 firmware but also that his model came with the 1.3.0 firmware. My unit came with firmware 1.2.0, and the temperature sensor function did not work.

You will need to have either firmware 1.3.0 or 1.4.0 for the temperature sensor functions to work. GPM reported no problems with his firmware upgrade, so you also may not have a problem with your upgrade.

Just to add to that I upgraded my firmware on a laptop running Windows 7, and went from 1.3.0 to 1.4.0. It could be that different versions of Windows may react to the upgrade differently. When I upgraded I didn't get any funny messages and Windows didn't want to restart - once the upgrade completed the device restarted and which means Windows thought it was disconnected (and then reconnected), but that should be normal. I also did the upgrade using the latest PCV software (1.0.3.2).

I tried to find a changelog for the PCV firmware, but couldn't, so who knows whats changes happen between versions, but I guess unless you hear otherwise it is always wise to update.

Out of interest kaldek, did your PCV come with a speed scalar and gearing pre-set up? Mine did, but I remember reading that CodeRighter's didn't. I am guessing firmware version and what is preconfigured will depend on how old the stock was that the PCV was taken from.

[kaldek]

So..... What do you have where EVAP would be connected, because that's the source for the vacuum switch.

Nothing:

But wouldn't the PAIR solenoid do just as well?

[Guest GPM]

So..... What do you have where EVAP would be connected, because that's the source for the vacuum switch.

A bunch of mounting points with nothing on them (probably a good spot to put a Stebel or something actually... hmmm, next project maybe).

Where exactly do you tap in the vacuum switch? I can't imagine Honda would completely redesign everything for non-EVAP markets, so where ever the vacuum source is, it's probably just plugged off (or still in use for anything else that taps into it).

[kaldek]

kaldek, did your PCV come with a speed scalar and gearing pre-set up? Mine did, but I remember reading that CodeRighter's didn't. I am guessing firmware version and what is preconfigured will depend on how old the stock was that the PCV was taken from.

My scalar was all wrong - something like 8,300 or thereabouts. I didn't check gearing, but just went straight into my own calibration.

Since upgrading to firmware 1.4.0, I have set my scalar to your value for Km/h (5638 - very tidy thanks!) and calibrated the gears again. Lovely!

I'm so geeky, I'll probably sit there with a multimeter tonight and perform a super-duper calibration of my temperature. :cheerleader:

[Guest Sammy40]

Hey GPM, I'm feeling a bit like we're the pioneers mate, forging a path for others to follow once all the gremlins are sorted! :cheerleader:

Yeah, stick with it boys :biggrin:

+ 1 to that lads! Friggin AWESOME EFFORT...oh and GPM is only up the road :goofy:

[sa1713]

So..... What do you have where EVAP would be connected, because that's the source for the vacuum switch.

A bunch of mounting points with nothing on them (probably a good spot to put a Stebel or something actually... hmmm, next project maybe).

Where exactly do you tap in the vacuum switch? I can't imagine Honda would completely redesign everything for non-EVAP markets, so where ever the vacuum source is, it's probably just plugged off (or still in use for anything else that taps into it).

Coderighter and I determined the difference between the EVAP models and non is where the four injector hoses terminate. On non EVAP bikes they terminate on the sides of the airbox. EVAP bikes have those same hoses terminating into a 5 way T where one hose exits to an EVAP solenoid.

Coderighter removed all of his EVAP system (including the solenoid) and used the vacuum hose exiting the 5 way as the vacuum source for his vacuum switch. This switch turns Autotune on/off depending on accel/decel.

On my 5th gen non EVAP model, I sourced a 5 way T and some vacuum hose from a member and I'll plumb that to the vacuum switch to work the same as Coderighter's.

[Guest GPM]

So..... What do you have where EVAP would be connected, because that's the source for the vacuum switch.

Nothing:

But wouldn't the PAIR solenoid do just as well?

Ok, I took my airbox out so I could take a gander at the throttle body - no superfelous vacuum hoses or vacuum 'nipples'. Crap. Looks like the California model has a different throttle body.

Studying what was there, and the service manual, the various vacuum hoses all come from the same source - for us non-cali owners there are the 4 tubes which go to a 5 way connector (this is part of the starter valve system and the 5th pipe goes off to the MAP sensor); a singe pipe running off to a one-way valve and continues on to the flapper valve; and a three way connector that leads to the fuel pressure regulator.

Considering those options, and keeping in mind that I am more or less undertaking a crash course in engine vacuum bits as I write this, I think the best option would be to tap into single pipe running off to the one-way valve (I frankly don't like the idea of fiddling with the other options if I don't have to). Am I right in thinking that the 'vacuum' in this line should be the same as for the evap lines (if they existed)? My idea would be to tap into the line *before* the one way valve, basically to get the vacuum as it is coming from the throttle body - a 3 way connector (and new pipe to the valve and vacuum switch). Or am I way off and is a vacuum switch solution just not possible on non-cali models?

Edited March 17, 2010 by GPM

[coderighter]

So..... What do you have where EVAP would be connected, because that's the source for the vacuum switch.

Nothing:

But wouldn't the PAIR solenoid do just as well?

Ok, I took my airbox out so I could take a gander at the throttle body - no superfelous vacuum hoses or vacuum 'nipples'. Crap. Looks like the California model has a different throttle body.

Studying what was there, and the service manual, the various vacuum hoses all come from the same source - for us non-cali owners there are the 4 tubes which go to a 5 way connector (this is part of the starter valve system and the 5th pipe goes off to the MAP sensor); a singe pipe running off to a one-way valve and continues on to the flapper valve; and a three way connector that leads to the fuel pressure regulator.

Considering those options, and keeping in mind that I am more or less undertaking a crash course in engine vacuum bits as I write this, I think the best option would be to tap into single pipe running off to the one-way valve (I frankly don't like the idea of fiddling with the other options if I don't have to). Am I right in thinking that the 'vacuum' in this line should be the same as for the evap lines (if they existed)? My idea would be to tap into the line *before* the one way valve, basically to get the vacuum as it is coming from the throttle body - a 3 way connector (and new pipe to the valve and vacuum switch). Or am I way off and is a vacuum switch solution just not possible on non-cali models?

Well the problem you might run into is the point on the throttle in which the signal is taken, mainly whether it's above or below the throttle plates. We need to get a signal that reflects throttle position, engine load. You're looking for a source that gives a high vacuum at idle and low (zero) with throttle wide open. You might be able to "T" before the one-way and get a good signal. I'll have to pull out a vac gauge and check. SA1713 described it well, I removed the EVAP purge solenoid and replaced it with the vacuum switch. Everything that was south of the solenoid went into the motorcycle spare parts bin. I had intended on removing the EVAP anyway and needed something to plug the line. That EVAP vacuum source gave a very smooth, linear engine load indication. I've got one of those vacuum hand pumps, the kind that comes with a brake bleed kit, and I stuck in the map window on my tank bag with the hose connected and went for a day ride. It seemed that cruise was 7-11 in, so once I got home, I used the hand pump to set the switch to trip at 14in and reset at 12 in. That was it, problem solved.

[Guest GPM]

Coderighter and I determined the difference between the EVAP models and non is where the four injector hoses terminate. On non EVAP bikes they terminate on the sides of the airbox. EVAP bikes have those same hoses terminating into a 5 way T where one hose exits to an EVAP solenoid.

Coderighter removed all of his EVAP system (including the solenoid) and used the vacuum hose exiting the 5 way as the vacuum source for his vacuum switch. This switch turns Autotune on/off depending on accel/decel.

On my 5th gen non EVAP model, I sourced a 5 way T and some vacuum hose from a member and I'll plumb that to the vacuum switch to work the same as Coderighter's.

So on the 5th gens do you have seperate vacuum plumbing for the EVAP and for the starter valves?

Looking at this little guide - http://www.justtees.co.uk/vfr/Honda%20VFR800Fi%20Starter%20Valves.pdf, it would seem the 4 pipes terminating at the airbox are used to sync up the starter valves, and being a UK bike it should be a non-cali model. On the 6th gen the starter valve plumbing set ends up in a 5-way that leads to our MAP sensor.

Well the problem you might run into is the point on the throttle in which the signal is taken, mainly whether it's above or below the throttle plates. We need to get a signal that reflects throttle position, engine load. You're looking for a source that gives a high vacuum at idle and low (zero) with throttle wide open. You might be able to "T" before the one-way and get a good signal. I'll have to pull out a vac gauge and check. SA1713 described it well, I removed the EVAP purge solenoid and replaced it with the vacuum switch. Everything that was south of the solenoid went into the motorcycle spare parts bin. I had intended on removing the EVAP anyway and needed something to plug the line. That EVAP vacuum source gave a very smooth, linear engine load indication. I've got one of those vacuum hand pumps, the kind that comes with a brake bleed kit, and I stuck in the map window on my tank bag with the hose connected and went for a day ride. It seemed that cruise was 7-11 in, so once I got home, I used the hand pump to set the switch to trip at 14in and reset at 12 in. That was it, problem solved.

Looking at the diagrams they all seem to come from about the same 'place'. At a guess the vacuum points we do have is common should be in the same places as on the cali and non-cali models (save time and effort engineering wise). In my mind the starter valve vacuum should vary with throttle, that makes sense when you do the sync process (small differences result in differences in vacuum, powering the guage). Combined with my above bit about the 5th gen seeming to recycle the same pipes for both starter sync and EVAP functions (if sa1713 is correct in the pipes that terminate normally going to the EVAP selenoid in a cali model) and I think those pipes may make for a suitable fall-back option. Looking at the throttle body the vacuum pipes tend to be on the oposite side of each other, but about level. Could be wishful thinking on my part but us non-cali owners may get lucky...

I would love to test it, but alas my brake bleeding tool is a 100ml syringe! (the 50c brake bleeding tool - works really well though)

Are there any other cheap ways to test it out - if it's like any other automotive product in this country that isn't tacky (and crappy) bling made in China, a hand vacuum pump will be terribly overpriced...

Edited March 17, 2010 by GPM

[coderighter]

Coderighter and I determined the difference between the EVAP models and non is where the four injector hoses terminate. On non EVAP bikes they terminate on the sides of the airbox. EVAP bikes have those same hoses terminating into a 5 way T where one hose exits to an EVAP solenoid.

Coderighter removed all of his EVAP system (including the solenoid) and used the vacuum hose exiting the 5 way as the vacuum source for his vacuum switch. This switch turns Autotune on/off depending on accel/decel.

On my 5th gen non EVAP model, I sourced a 5 way T and some vacuum hose from a member and I'll plumb that to the vacuum switch to work the same as Coderighter's.

So on the 5th gens do you have seperate vacuum plumbing for the EVAP and for the starter valves?

Looking at this little guide - http://www.justtees.co.uk/vfr/Honda%20VFR800Fi%20Starter%20Valves.pdf, it would seem the 4 pipes terminating at the airbox are used to sync up the starter valves, and being a UK bike it should be a non-cali model. On the 6th gen the starter valve plumbing set ends up in a 5-way that leads to our MAP sensor.

Well the problem you might run into is the point on the throttle in which the signal is taken, mainly whether it's above or below the throttle plates. We need to get a signal that reflects throttle position, engine load. You're looking for a source that gives a high vacuum at idle and low (zero) with throttle wide open. You might be able to "T" before the one-way and get a good signal. I'll have to pull out a vac gauge and check. SA1713 described it well, I removed the EVAP purge solenoid and replaced it with the vacuum switch. Everything that was south of the solenoid went into the motorcycle spare parts bin. I had intended on removing the EVAP anyway and needed something to plug the line. That EVAP vacuum source gave a very smooth, linear engine load indication. I've got one of those vacuum hand pumps, the kind that comes with a brake bleed kit, and I stuck in the map window on my tank bag with the hose connected and went for a day ride. It seemed that cruise was 7-11 in, so once I got home, I used the hand pump to set the switch to trip at 14in and reset at 12 in. That was it, problem solved.

Looking at the diagrams they all seem to come from about the same 'place'. At a guess the vacuum points we do have is common should be in the same places as on the cali and non-cali models (save time and effort engineering wise). In my mind the starter valve vacuum should vary with throttle, that makes sense when you do the sync process (small differences result in differences in vacuum, powering the guage). Combined with my above bit about the 5th gen seeming to recycle the same pipes for both starter sync and EVAP functions (if sa1713 is correct in the pipes that terminate normally going to the EVAP selenoid in a cali model) and I think those pipes may make for a suitable fall-back option. Looking at the throttle body the vacuum pipes tend to be on the oposite side of each other, but about level. Could be wishful thinking on my part but us non-cali owners may get lucky...

I would love to test it, but alas my brake bleeding tool is a 100ml syringe! (the 50c brake bleeding tool - works really well though)

Are there any other cheap ways to test it out - if it's like any other automotive product in this country that isn't tacky (and crappy) bling made in China, a hand vacuum pump will be terribly overpriced...

Sounds like it's all sorted then. As far as the pump/gauge, really it could be tacky (and crappy) bling made in China. It doesn't have to be accurate, just consistent. As long as your using the same gauge to read the level, as you use to set the level, you should be fine. It's all relative.

[kaldek]

I would love to test it, but alas my brake bleeding tool is a 100ml syringe! (the 50c brake bleeding tool - works really well though)

Are there any other cheap ways to test it out - if it's like any other automotive product in this country that isn't tacky (and crappy) bling made in China, a hand vacuum pump will be terribly overpriced...

Mate, I've got a vacuum gauge. Heck, I've got a handheld one as well as another four bolted to my carb balancing kit.

You want me to go for a ride and measure the vacuum readings for you?

[coderighter]

I would love to test it, but alas my brake bleeding tool is a 100ml syringe! (the 50c brake bleeding tool - works really well though)

Are there any other cheap ways to test it out - if it's like any other automotive product in this country that isn't tacky (and crappy) bling made in China, a hand vacuum pump will be terribly overpriced...

Mate, I've got a vacuum gauge. Heck, I've got a handheld one as well as another four bolted to my carb balancing kit.

You want me to go for a ride and measure the vacuum readings for you?

I still think it's best to use the same gauge for testing and setting.

[Guest GPM]

Mate, I've got a vacuum gauge. Heck, I've got a handheld one as well as another four bolted to my carb balancing kit.

You want me to go for a ride and measure the vacuum readings for you?

I agree with Coderighter that when it comes to implementation, test and set with the same device. But at this stage it would be nice to have some proof of concept - ie. do those vacuum lines give the desired changes in vacuum when the throttle is being opened, held and closed?

IMHO there is not much point continuing down the current path if it is not going to work.

So I think give it a go and see what sort of results you come up with - then you can use your settings, and I'll get out my wallet and pick up the requisite parts :fing02:

[kaldek]

So I think give it a go and see what sort of results you come up with - then you can use your settings, and I'll get out my wallet and pick up the requisite parts :fing02:

No problems. I will hook it into the vacuum line used for the flapper valve - it comes off that group of hoses in the throttle body, so it will be a good test.

[Guest GPM]

So I think give it a go and see what sort of results you come up with - then you can use your settings, and I'll get out my wallet and pick up the requisite parts :fing02:

No problems. I will hook it into the vacuum line used for the flapper valve - it comes off that group of hoses in the throttle body, so it will be a good test.

Just be sure to tap in before the one-way-valve - you can fish it out with just lifting the tank (it sits beside the airbox on the left hand side). If you have already disabled the flapper valve it wont make an ounce of difference tapping in here.

[Guest GPM]

Ok gentlemen, I have some interesting new findings relating to the accelpump feature.

Basically I had noticed some noise under hard acceleration, I figured it was either the flapper getting a bit chattery (as this was suburban riding, so getting off quick as I could from lights, thus I travelled through the flapper RPM range) or it was engine knock (probably because I had 4 week old fuel in the tank, and only a small amount at that).

I thus decided to play with my accelpump feature a little to see if I could refine its 'disable autotune and let the Honda ECU accelpump do its magic' ability (as explained by Coderighter here).

Now the latest version off the PCV software allows you to not only set the TPS delta for the accelpump, but actually capture it (by storing the input when you give the throttle a good twist) and gives a live display of the delta as you sit there playing with your throttle. This I did, and discovered an interesting thing - I have NO idea where Dynojet came up with the suggested setting of 90% delta. Even when I was twisting the throttle in a way I would never try with the engine running (basically trying to open and close it as fast as I could) I was only getting a delta of 60%. From this I concluded that having this feature on and the delta at 90% per Dynojets recommendation is pointless.

It could be that Dynojet has changed the way the delta is calculated in the latest firmware (and thus their suggestion is still current for PCVs pre 1.4.0 and PCIIIs), but that just doesn't make sense to me.

Another interesting thing I noticed is that the delta readout was quite happy to show negative figures. Indeed, whenever I closed the throttle that it exactly what it would do. Now that is interesting as it means that a 'decelpump' type feature that I mentioned in my original post is entirely possible, even an easy feature to add in the next firmware (I may fire an email off to Dynojet about that as a suggestion).

Then I thought, what would happen if I set the delta to a negative figure now? I needed to go get some new fuel, so why not give it a shot. I reset my trim tables so that they had nothing in them, and set the delta to -2.5% (which matched up with a deliberate roll off of the throttle, but wouldn't hamper trigger on small speed adjustments) and set off. When I got back I plugged in my laptop (kudos permanent USB cable for making that all too easy) and looked at my trim - and it was full of adjustments. Ok, that's a little odd; this was quite a long shot so I didn't expect that at all! Ok, time for another little test, lets ramp up the negative delta to something silly, -90%. To achieve that sort of delta I would not so much be rolling off the throttle as trying to rip it off! Reset the trim and went for another quick ride, just around my local area. Got home and again, trim is full of adjustments - ok, that rules out the previous readings being from when I was closing the throttle (and thus getting a delta below -2.5%).

To me this raises several possibilities:

1) The theory that accelpump disables autotune from making any further adjustments for it's duration is incorrect (which I believe goes against Dynojets documentation).

2) When you enter a negative figure in the delta the PCV just ignores the negative part of it and treats it as positive figure.

3) Related to the previous one, when the PCV sees a negative figure it just ignores the accelpump totally (effectively a negative figure disables the feature as the firmware doesn't understand it).

4) When you enter a negative delta the accelpump activates on any delta reading less then that negative figure (ie. when you are closing the throttle at a rate greater than the one specified).

My findings do, however, seem to totally remove my original thought that if you set a negative delta the accelpump will be constantly active on increasing or steady throttle, and only disable at the set rate of throttle roll-off (unless possibility 1 above is correct, in which case this is still possible).

The exciting part to me, is possibility 4 - it is a long shot (for it to be the case the Dynojet engineers must have had some good foresight - but why not publish it as a feature?), because it could solve the over-rich-on-decel issue - at least where the decel is due to throttle roll off (if you are decel-ing due to a hill, it may still richen up, but the rate of decel should be low enough not to have dramatic effects; if you are decel-ing under brakes, well, you should have closed the throttle anyway so autotune has already stopped listening).

Now because I do love a good graph, here is some comparisons of the fuel tables for 2nd gear before I went for a ride with the -2.5% delta, and after.

No tell tale enrichments there, which is what you would expect under the first 3 possibilities - however, while it is easier to cause the over enrichment on decel problem in suburban riding, we are talking a 15 minute tour here, so the figures thus far cannot really prove any of the possibilities to be true.

Hmmmm, what a curious little device this is.

Edited March 19, 2010 by GPM

[coderighter]

Ok gentlemen, I have some interesting new findings relating to the accelpump feature.

Basically I had noticed some noise under hard acceleration, I figured it was either the flapper getting a bit chattery (as this was suburban riding, so getting off quick as I could from lights, thus I travelled through the flapper RPM range) or it was engine knock (probably because I had 4 week old fuel in the tank, and only a small amount at that).

I thus decided to play with my accelpump feature a little to see if I could refine its 'disable autotune and let the Honda ECU accelpump do its magic' ability (as explained by Coderighter here).

Now the latest version off the PCV software allows you to not only set the TPS delta for the accelpump, but actually capture it (by storing the input when you give the throttle a good twist) and gives a live display of the delta as you sit there playing with your throttle. This I did, and discovered an interesting thing - I have NO idea where Dynojet came up with the suggested setting of 90% delta. Even when I was twisting the throttle in a way I would never try with the engine running (basically trying to open and close it as fast as I could) I was only getting a delta of 60%. From this I concluded that having this feature on and the delta at 90% per Dynojets recommendation is pointless.

It could be that Dynojet has changed the way the delta is calculated in the latest firmware (and thus their suggestion is still current for PCVs pre 1.4.0 and PCIIIs), but that just doesn't make sense to me.

Another interesting thing I noticed is that the delta readout was quite happy to show negative figures. Indeed, whenever I closed the throttle that it exactly what it would do. Now that is interesting as it means that a 'decelpump' type feature that I mentioned in my original post is entirely possible, even an easy feature to add in the next firmware (I may fire an email off to Dynojet about that as a suggestion).

Then I thought, what would happen if I set the delta to a negative figure now? I needed to go get some new fuel, so why not give it a shot. I reset my trim tables so that they had nothing in them, and set the delta to -2.5% (which matched up with a deliberate roll off of the throttle, but wouldn't hamper trigger on small speed adjustments) and set off. When I got back I plugged in my laptop (kudos permanent USB cable for making that all too easy) and looked at my trim - and it was full of adjustments. Ok, that's a little odd; this was quite a long shot so I didn't expect that at all! Ok, time for another little test, lets ramp up the negative delta to something silly, -90%. To achieve that sort of delta I would not so much be rolling off the throttle as trying to rip it off! Reset the trim and went for another quick ride, just around my local area. Got home and again, trim is full of adjustments - ok, that rules out the previous readings being from when I was closing the throttle (and thus getting a delta below -2.5%).

To me this raises several possibilities:

1) The theory that accelpump disables autotune from making any further adjustments for it's duration is incorrect (which I believe goes against Dynojets documentation).

2) When you enter a negative figure in the delta the PCV just ignores the negative part of it and treats it as positive figure.

3) Related to the previous one, when the PCV sees a negative figure it just ignores the accelpump totally (effectively a negative figure disables the feature as the firmware doesn't understand it).

4) When you enter a negative delta the accelpump activates on any delta reading less then that negative figure (ie. when you are closing the throttle at a rate greater than the one specified).

My findings do, however, seem to totally remove my original thought that if you set a negative delta the accelpump will be constantly active on increasing or steady throttle, and only disable at the set rate of throttle roll-off (unless possibility 1 above is correct, in which case this is still possible).

The exciting part to me, is possibility 4 - it is a long shot (for it to be the case the Dynojet engineers must have had some good foresight - but why not publish it as a feature?), because it could solve the over-rich-on-decel issue - at least where the decel is due to throttle roll off (if you are decel-ing due to a hill, it may still richen up, but the rate of decel should be low enough not to have dramatic effects; if you are decel-ing under brakes, well, you should have closed the throttle anyway so autotune has already stopped listening).

Now because I do love a good graph, here is some comparisons of the fuel tables for 2nd gear before I went for a ride with the -2.5% delta, and after.

No tell tale enrichments there, which is what you would expect under the first 3 possibilities - however, while it is easier to cause the over enrichment on decel problem in suburban riding, we are talking a 15 minute tour here, so the figures thus far cannot really prove any of the possibilities to be true.

Hmmmm, what a curious little device this is.

Actually, since that post, another Dynojet tech support rep told me that normal 'accelerator pump' setting wouldn't happen long enough for the Autotune to act on it. This isn't the first time I've gotten different answers to the same question. Because I have been trying to develop a real good base map, I currently have the 'accelerator pump' feature off.

On kind of a side note, I've read that Honda uses temp more than most manufactures as a factor in fuel mapping. Reportedly, as little a 3 degrees can cause a change in mixture. I've been meaning to check this, but it's been a crazy last couple months for me and haven't had much time to play.

I've also found the speed tables for gear by gear given by Dynojet are pretty close, but not exact. The table can be mathematically calculated from the known gear ratios in the service manual, but my question is where does the 'scaler' number come from?

[Guest GPM]

Actually, since that post, another Dynojet tech support rep told me that normal 'accelerator pump' setting wouldn't happen long enough for the Autotune to act on it. This isn't the first time I've gotten different answers to the same question. Because I have been trying to develop a real good base map, I currently have the 'accelerator pump' feature off.

Setting the accelpump to 100 revs would equal 1 second at 6000RPM - just how slow is the autotune?

On kind of a side note, I've read that Honda uses temp more than most manufactures as a factor in fuel mapping. Reportedly, as little a 3 degrees can cause a change in mixture. I've been meaning to check this, but it's been a crazy last couple months for me and haven't had much time to play.

Probably the best way is to set up some power source that makes the bike think it is a constant temp outside, then change and compare results. It would mean getting to a position where the trim maps are basically all 0s would be difficult though, as Honda's map keeps changing to the environment (more so then other bikes anyway).

I've also found the speed tables for gear by gear given by Dynojet are pretty close, but not exact. The table can be mathematically calculated from the known gear ratios in the service manual, but my question is where does the 'scaler' number come from?

I am guessing the scalar is the number by which you divide the VSS pulses.

So VSS reading in hz / scalar = speed. That matches the MPH scalar being higher then the KMH scalar. (note there may be more to that calculation then I am guessing here, but you get the idea).