TPS adjust/TB balance/air bleed screws

[Tom M]

What? No power commander?!? Then you will likely benefit from increased TPS millivolts.

The 150mV reading is done with engine not running. (technically debatable, but it is too tricky to run the engine on one cylinder)

The 521mV reading is done with engine running (because it can be done easily and reflects real running conditions better)

 

I do have a PCIII.

[raz]

Step one - Set your valves to world settings

Step two - Set your bleed screws to open 1 full turn

Step three - Synch throttle bodies at just off idle (around 1800 rpm)

Step four - Set idle to 1100 using left idle screw adjuster only

Step five - Set TPS to 3.6 degrees (I forget what that translates to in mv..someone here will know)

Step six - Ensure idle trim is set to zero

What if this procedure is carried out in one case with a base TPS setting (at step 1-4) of 120 mV, and in another case 200 mV. This procedure will not, as I understand it, come out with the same results in those two, not very extreme, cases. And even worse in more extreme cases. Not sure if it matters much. And if it does, maybe the idle rpm will change enough in step five that you will instinctively want to go back to step four again and redo from there.

 

Never mind, I'm just thinking out loud. It would be interesting to measure what base TPS this will produce!

[badmotogoozer]

My bike (01 sport) was untunable using other methods. I used Micha's method and after one iteration it ran perfectly. Put my digital tach on and it was idling exactly at 1150rpm as spec'd.

 

As mentioned, Micha knows a thing or two...

[Tom M]

OK. I just retuned using the Micha method that Mr Bean described. The bike runs smoooth, no more coughing at low throttle. It feels richer, maybe doesn't pull quite as hard as before, but that's just a quick impression after a short night ride. I'm going to ride it like this for a while and check the plugs. They only have a 300 or so miles on them, were very clean but not white before retuning tonight. I might have been running lean. I'll be interested to see if they read rich or spot on in a few days.

 

Dave, I checked the 150mV setting before retuning. It still read 150 with everything backed off, but I found that if I pushed on the throttle linkage I could knock it down another 18mV to 132, and it would stay there when I took my finger away. If I moved it and let the spring return it it went back to 150 again. I also checked full throttle with engine off, saw 4.78V. After the reset with Micha method (532mV at 1100-1150 rpm idle) I saw 4.82V WFO with engine off.

[cycdude6]

 

Step six - Ensure idle trim is set to zero

 

How the heck do you ensure the idle trim is set to zero?

John

[Mr. Bean]

Step six - Ensure idle trim is set to zero

 

How the heck do you ensure the idle trim is set to zero?

John

It requires the use of either the Axone or the much more reasonably priced VDSTS software from TechnoResearch. GuzziTech sells it.

[dlaing]

What if this procedure is carried out in one case with a base TPS setting (at step 1-4) of 120 mV, and in another case 200 mV. This procedure will not, as I understand it, come out with the same results in those two, not very extreme, cases. And even worse in more extreme cases. Not sure if it matters much. And if it does, maybe the idle rpm will change enough in step five that you will instinctively want to go back to step four again and redo from there.

 

Never mind, I'm just thinking out loud. It would be interesting to measure what base TPS this will produce!

Those are excellent points.

The Method Ryland, others, and I came up with should produce much more accurately reproducible results.

But apparently not from one bike to another...

[dlaing]

I do have a PCIII.

Sorry! That is right, you mentioned that you zero'd out the PCIII.

 

OK. I just retuned using the Micha method that Mr Bean described. The bike runs smoooth, no more coughing at low throttle. It feels richer, maybe doesn't pull quite as hard as before, but that's just a quick impression after a short night ride. I'm going to ride it like this for a while and check the plugs. They only have a 300 or so miles on them, were very clean but not white before retuning tonight. I might have been running lean. I'll be interested to see if they read rich or spot on in a few days.

 

Dave, I checked the 150mV setting before retuning. It still read 150 with everything backed off, but I found that if I pushed on the throttle linkage I could knock it down another 18mV to 132, and it would stay there when I took my finger away. If I moved it and let the spring return it it went back to 150 again. I also checked full throttle with engine off, saw 4.78V. After the reset with Micha method (532mV at 1100-1150 rpm idle) I saw 4.82V WFO with engine off.

Thanks Tom!

Not exactly the result I was hoping for, but your posting all the numbers gives clarity to why your bike would not tune from the non-Micha method.

It is pretty clear that the difference between your idle position and your fully closed position is different than mine and other bikes.

I'd have to check my numbers, by mine goes from fully closed 150mV to 521mV at about 1150RPM and about 1 turn out bypass and at WOT I think it reads 4.86V.

Yours went from 150mV to 440mV at about 1150RPM and half turn out bypass and WOT reading 4.78V, and now probably now goes from maybe about roughly 200-250mV fully closed to 532mV at about the same 1150rpm and 1 turn out bypass and 4.82V at WOT!!!!

We don't know what your fully closed number is now, but you had to increase the idle TPS millivoltage by 92mV from 440 to 532 with more bypass, which probably means the fully closed TPS probably increased about 100mV to 250mV while the WOT appears to have only increased by 40mV.

Very interesting

But Darn, it is getting more difficult to write instructions that will make every bike happy!!!

Do we need to start at 150mV, weigh in the resulting idle TPS mV and WOT Voltage, and change by modifiers to create the perfect compromise which will vary depending on Ti ECU/regular ECU/regular pipes/ front crossover pipes?????

And once it is set, we should probably note the fully closed TPS reading so that we can return to it.

No wonder the various manuals kept changing the numbers and being vague!!!!

[mark.gilmore]

Hay Tom,good stuff.we just need to no what your everything backed off TPS is now.there is a bike in town with similar probs.

and 3.6 degrees in mv?

[Tom M]

Dave, maybe you could mention the Micha method at the end of the pinned instructions for bikes like mine that can't be tuned using your instructions? I'll try to check my TPS with linkage disconnected some time soon and post the result. I haven't been to a Guzzi dealer to verify that the ECU trim is set to zero. Not sure if I will bother since it's running pretty good.

 

Mark, 3.6 degrees is 532mV according to the chart here.

[waspp]

It sounds like Micha has developed the "mechanics shortcut" which often works as well as page after page of detailed instuctions to be followed by the truly anal. So by setting the 532mv at idle (and not being concerned with the 150mv at throttle plate closed postion) does that change the range of fuel and timing by the ecu? As Dave said the mv reading at the closed throttle plate position may vary greatly from bike to bike. Is this a problem or is the position of the TPS most critical at the idle position?

[cycdude6]

Why is the 150mv setting at key-on bike-off so important? It seems to me the setting (whatever it is) at running idle would be a lot more important as it represents actual running conditions. Anyway, I couldn't get 150mv after following all the instructions, but I found the bike runs great at 527mv running idle (1150 rpm).

 

My question is this; my bike is running rich as evidenced by the blackish sparkplugs and 36 mpg, which way should I go to lean the curve, more millivolts or less?

 

Thanks, John

[dlaing]

Why is the 150mv setting at key-on bike-off so important? It seems to me the setting (whatever it is) at running idle would be a lot more important as it represents actual running conditions. Anyway, I couldn't get 150mv after following all the instructions, but I found the bike runs great at 527mv running idle (1150 rpm).

 

My question is this; my bike is running rich as evidenced by the blackish sparkplugs and 36 mpg, which way should I go to lean the curve, more millivolts or less?

 

Thanks, John

less millivolts generally makes it run leaner.

The 150mV reading is important because it establishes the baseline to the Air:Fuel Ratio.

But if the butterfly valve does not seat properly it loses its usefulness.

Setting to idle does set to true flow, but only at idle.

At WOT and all the points close to WOT the 150mV theoretically is a better base line.

At what throttle opening does idle become more important than baseline is anyone's guess and certainly varies from bike to bike.

How many of us are even using an accurate tach to measure idle RPM?

[dlaing]

It sounds like Micha has developed the "mechanics shortcut" which often works as well as page after page of detailed instuctions to be followed by the truly anal.

I'll get start on those pages this weekend...

[mark.gilmore]

Mark, 3.6 degrees is 532mV according to the chart here.

Thanks Tom