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Experiences of a PCV with Autotune on a 2004 VFR800


Guest GPM

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  • 1 month later...
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So as an interesting update to the Autotune discussions, I have just listed mine for sale on eBay.

Basically, after having a custom tune done, the benefits offered by the Autotune just didn't materialise. The only place I really cared about tuning were the throttle positions and rpms where the Autotune was unable to really make a difference. The main problem was needing to find the right AFR value - which is unique per bike for the best experience - and the need to use a vacuum-controlled switch to remove the problems caused by decelerating on an open throttle.

In essence, my tuning shop had to put values in my PCV map you wouldn't normally expect to put in, so that I have smooth throttle response. So rather than a computer working it out, my tuning guy sat there and thought "outside the box" to get me a good working map. And being a computer, the Autotune can't do creative thinking on the fly. So, given the cost of the Autotune ($375) versus the cost of a custom tune ($350), it was not able to make a level of difference that matched its price.

I suppose I migh get flamed by Coderighter and GPM for saying all this. Sorry folks!

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So as an interesting update to the Autotune discussions, I have just listed mine for sale on eBay.

Basically, after having a custom tune done, the benefits offered by the Autotune just didn't materialise. The only place I really cared about tuning were the throttle positions and rpms where the Autotune was unable to really make a difference. The main problem was needing to find the right AFR value - which is unique per bike for the best experience - and the need to use a vacuum-controlled switch to remove the problems caused by decelerating on an open throttle.

In essence, my tuning shop had to put values in my PCV map you wouldn't normally expect to put in, so that I have smooth throttle response. So rather than a computer working it out, my tuning guy sat there and thought "outside the box" to get me a good working map. And being a computer, the Autotune can't do creative thinking on the fly. So, given the cost of the Autotune ($375) versus the cost of a custom tune ($350), it was not able to make a level of difference that matched its price.

I suppose I migh get flamed by Coderighter and GPM for saying all this. Sorry folks!

Ah.... Come on, I'm not the flaming type!

Hey, you got to do what works for you. I think we're in different situations. Your bike is an '04 so you don't have the map by gear like the '06 and later have. In theory, one map should work for you. If I could even talk someone around here to map each gear, I'm sure it would cost me much a lot than $350. Besides, I paid $195 for the Autotune.

It sounds like you have a good tuner available. Every 'map' I've seen done by a local tuners around here, is a Dynojet map with some changes in the 100% throttle column.

I've had really good luck with my Autotune. That said, it's not perfect and it does require a lot of interaction to get good results. I'm also thinking there will be some firmware changes coming to deal with some of the short comings. (I would really like to see a temp sampling window that could be setup).

I like to tinker. Since there is no airflow meter, any tinkering that has an effect on airflow, requires a map change. I don't want to visit the 'tuner' whenever I tinker.

As the bike ages, things will change. There's a spring in the fuel pressure regulator, springs over time 'relax'. Even with the best gas, over time the injectors will flow a little less. In theroy, the Autotune should correct for those little changes.

Wasn't there a member a while back that had a engine failure that was linked to a low flowing injector?

Just some thoughts.

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I think it's worth posting that I've reinstalled my Autotune - absolutely nobody wanted to buy it!

But more importantly, has anyone noticed all the updates to the PCV software lately? Two firmware updates this year and also two application updates.

Some of the new stuff looks to be Autotune tables based on air pressure readings, rather than throttle position. There are also fuel trim tables based on fuel pressure rather than throttle position as well. I wonder if there's any applicability there for us VFR owners?

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For a thousand bucks it ought to be plug and play, no adjustment necessary, nice write up though, Id rather go ride the reliable stock unit, than fk with that chit.

Thankyou for saving Us >G

Edited by spud786
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Well this is interesting. I fitted my Autotune back to the bike and turned it on, left it on, and rode to work. Only a few cells were modified, and even then only a few points up or down.

This is actually what I was hoping for some time ago but didn't seem to get. It's been so long since I disconnected the Autotune (July 2010) that I can't rememebr if I even bothered testing it after I had my custom tune done on the dyno.

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  • 2 weeks later...
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I have a PCV /Autotune for 4000 Km now, on a European '06 model, having some issues below 5K rpms, 2% to 40% throttle and in 1st, 2nd and 3rdgear.

I have blocked PAIR valve, checked injectors and using a vacuum switch toturn O2 sensor off during deceleration.

When I accept trims for several times, in a number of cells the fuel adjusts from -20 to +20 or more every250 rpm up until 5+k.

I bought autotune having in mind to make the motor smooth. I realize now that this is not possible.

In case that the base map in second gear has AF ratio about 13.3 then +20% is 10.7 and -20% is 16 way outof 12.6 to 15 acceptable range.

I think that this happens by two factors:

1. Fuel cut in deceleration makes cells richer. A vacuum switch helps but just before throttle is completely closed, not when deceleration starts.

2. During acceleration ECU richens mixture for some cycles and at that point autotune makes cells lean.

PCV/autotune shouldhave built-in functions of stopping data logging of O2 sensor automatically during acceleration and deceleration. As it is, PCV/Autotune is not a mature combination despite all that marketing.

A solution I see is to accelerate with throttle in certain position and gear eg 20% / 2ndgear, from 1500 to 5000 rpms then press the clutch, stop, accept trims and zero the 20% column in of the AF table.

Otherwise, to build something that cuts autotune off when injectors are not working (fuel-cut), aswell as during a certain positive Delta (acceleration) for a number of cycles.

What really pisses me off is that such functions should already be present inPCV.

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  • 5 months later...
  • 3 months later...

I finaly installed the PCV wt AutoTune on my 2003 VTEC but I got some troubles. :computer-noworky: First the temperature is not showing in the computer display, no gear, speed or AFR. The temperature & speed signals are getting in. I've cheched the temp voltage signal and is the same as GPM (1.48V @ 54deg). The speed signal should be also ok because I'm using the same signal used for GIpro X and were installed in the same time. I'll try the speed & gear calibrations myself soon. The autotune LED is flashing but I have no ideea what that means and I get zero value on AFR which, the manual say, is might be the CAN cable. The CAN cable is ok to have only 2 wires? For some reason I have only 2. :blink:

Any sugestions?

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putting aside the Can cable (and so the uselessfulness of the autotune at the moment) the PCV works great. I can't believe that I don't need to use the clutch at low speed & rpm - no fuss between 1-3k rpm in first & second gears. and the vtec transition is gone completely as far as I can tell. this is a great investment & I'm happy abt it. :bliss:

unfortunately I don't have time to fiddle with it 'cause I'm going to work (sailor) but I'll see to it on return.

in the mean time can anybody post a picture of how a Can cable should look like - I'm interested more in the wire arrangement on both conectors.

many thanks!

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  • 2 months later...

Eventually I've written to dynojet and they told me that 2 wires cable is ok since the autotune needs only these two for communicating with the pcv ... for those wandering by themselves as I did. cheers!

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