Throttle Position Sensor

[Tom M]

Tom, why 530? The main thread says 520. Would my K&N's be leaning out the air mixture? Does the TPS reading equate to a fuel mixture, where 530 would be a bit richer?

 

At the bottom of the TPS post in the FAQ Dave included a chart that shows degrees of throttle opening and the corresponding voltages. .530 volts = 3.6 degrees, which is what the shop manual (and Micha) says the TPS should read at idle. The shop manual says 1050 +/-50 rpm for idle, most find 1100 is good. Honestly I don't think anyone could tell the difference between 520 or 530 mV.

 

If your idle is 1400rpm but your tps is at 520 your engine is getting enough fuel for about 1000-1050 rpm which means it's lean. Before you bring your bike to a shop try the Micha method.

 

BTW Micha is a mechanic at Moto International which is one of the largest Guzzi dealers in the country. If I recall correctly Greg Field, a fellow MI employee and forum member here, said Micha came up wit this method after tuning lots and lots of V11s that didn't respond well to the standard TPS setting method. Many members here over the years have used it with good results. Some, like me, Mr Bean, and badmotogoozer, absolutely could not use the method posted in the FAQ. Like you I found my idle was way too high if I did. I don't recall ever seeing a post from someone who said their bike ran worse after trying it, but many, like you and me, had trouble with the posted method.

[docc]

Is the mV at idle setting the only thing different about the MI method? (most of us have found that something around 530 mV is best)

 

Otherwise, when my tach shows 1400 rpm that is 1100.

[thebronze]

I started over last night and found that the fully closed tps reading was 185. I guess the set screws werent tight enough and it crept. So I set it to 150mv closed and the idle was 520. Still lean and hiccuping between 3-4k rpm. Took it apart and set it to 160mv fully closed and will try 530 at idle tonight.

 

I was thinking about making a video of the tps reading and posting it on youtube. Think that would be a help to anyone or is there already one out there?

[Tom M]

Is the mV at idle setting the only thing different about the MI method? (most of us have found that something around 530 mV is best)

 

Otherwise, when my tach shows 1400 rpm that is 1100.

 

The main difference isn't the 530mV setting, it'd the fact that it completely discards the steps that require you to set the TPS to 150mV with the linkage disconnected ,it says to just open the air bleed screws to 1 full turn and leave them there before balancing the TBs, and it has you set the idle at 1100rpm with the idle adjust screw and THEN set the TPS to 530mV. It's really much quicker and easier than the FAQ method.

 

FWIW my tach is very close to what I see with VDST at idle. On the other hand my speedo is about 10% optimistic...

[Tom M]

I started over last night and found that the fully closed tps reading was 185. I guess the set screws werent tight enough and it crept. So I set it to 150mv closed and the idle was 520. Still lean and hiccuping between 3-4k rpm. Took it apart and set it to 160mv fully closed and will try 530 at idle tonight.

 

I was thinking about making a video of the tps reading and posting it on youtube. Think that would be a help to anyone or is there already one out there?

 

A video wouldn't do anything for me.

 

FYI some members whodon't have power commanders and have added pods and/or aftermarket exhaust have adjusted their TPS a little higher than .530 mV at idle to richen the mixture a bit. You might want to try .540 if you think you're still lean at .530.

[thebronze]

 

FYI some members whodon't have power commanders and have added pods and/or aftermarket exhaust have adjusted their TPS a little higher than .530 mV at idle to richen the mixture a bit. You might want to try .540 if you think you're still lean at .530.

 

I'm giving up for now. I dont think my problem is the TPS setting. Ive now run the idle tps at 520, 530, 540 with the corresponding values at unhooked throttle rod. TB's are balanced, idle around 1100 and I still have the same problem. Valve lash is set to raceco specs which I think is way too loose. I cleaned up the throttle bodies last night, they were really dirty but it didnt help.

 

The bike runs perfectly until about 10-15 minutes, then it starts to hiccup and sputter. I think its either the oil temp switch or the air temp switch are not working and its leaving the mixture lean. The bike is unrideable between 2-4k rpm once its warmed up. If the TPS was making it lean, it should be lean in those first 15 minutes of ride time. But the problem only shows up when the bike is properly warmed up.

 

Is there a way to test the engine oil temp sensor? Similar to probing the tps sensor? I guess the vdst software would tell me all this.

[Tom M]

Is there a way to test the engine oil temp sensor? Similar to probing the tps sensor? I guess the vdst software would tell me all this.

 

I agree that it doesn't seem that the TPS setting is your problem. There are charts in the shop manual that shows what resistance you should see from the air and oil temp sensors at given temperatures. You could try testing those sensors, but it really would be easier and more accurate to see what the ECU is seeing by hooking up to the factory diagnostic tool or VDST.

 

Apparently there's a Ducati diagnostic out there for free that will communicate with our ECU but you would need an interface cable. I don't have any details or experience with it but I'm sure you can find it with a little digging.

 

Here's a source for the shop manual if you don't already have one: http://thisoldtractor.com/gtbender/moto_guzzi_misc.htm#gtb_workshop_manuals___shop_manuals___service_manuals

 

Are you absolutely sure that you don't have any intake or exhaust leaks? A crack in an intake rubber, or to a lesser extent an exhaust leak near the cylinder could give the symptoms that you have.

 

Hope this helps,

Tom

[thebronze]

 

Are you absolutely sure that you don't have any intake or exhaust leaks? A crack in an intake rubber, or to a lesser extent an exhaust leak near the cylinder could give the syptoms that you have.

 

Hope this helps,

Tom

 

IDK, ive had vacuum leaks before and they arent dependant on the engine temp. Seems to me that whatever sensor says "engine is now warm, add or remove fuel to mix" isnt working.

[docc]

You might try repositioning your intake air sensor and/or provide some air flow to it (I recall yours is mounted in a canister or such.)

 

There has been some considerable debate about the Engine Temperature Sensor. IMO, it's worth looking into.

 

FWIW, I totally agree with Tom's approach to tuning. I suppose we should update the FAQ with the alternative, simplified method.

[HaydnR]

 

 

FWIW, I totally agree with Tom's approach to tuning. I suppose we should update the FAQ with the alternative, simplified method.

 

I've been following this thread for a while and whilst I can see in some circumstances the simplified method will work in others it will not. When I am sober I will explain further but in short the tps is a base reference for the fueling and ignition map. If this is not calibrated (zero'd) correctly all the other adjustments may as well be guess work , 520mv,530mv,400mv 600mv at idle is completely irrelevant as the idle can then be incorrectly set (fooled) by altering the air bleed and co trim and once off idle the fuel map will be followed correctly so long as the base setting (150mv) is correct. The fuel map (fuel to air ratio) can be tricked if the tps base setting is altered eg.if the base setting is set high say 300mv fully closed the ecu (map) will deliver more fuel with the butterfly (air) at a lesser degree of opening.

 

With Mr bronze's problems I would guess that it could be ignition related, coils,leads, caps or plugs breaking down with heat.

[thebronze]

I've been following this thread for a while and whilst I can see in some circumstances the simplified method will work in others it will not. When I am sober I will explain further but in short the tps is a base reference for the fueling and ignition map. If this is not calibrated (zero'd) correctly all the other adjustments may as well be guess work , 520mv,530mv,400mv 600mv at idle is completely irrelevant as the idle can then be incorrectly set (fooled) by altering the air bleed and co trim and once off idle the fuel map will be followed correctly so long as the base setting (150mv) is correct. The fuel map (fuel to air ratio) can be tricked if the tps base setting is altered eg.if the base setting is set high say 300mv fully closed the ecu (map) will deliver more fuel with the butterfly (air) at a lesser degree of opening.

 

With Mr bronze's problems I would guess that it could be ignition related, coils,leads, caps or plugs breaking down with heat.

 

Well my problems just got better. I replaced the oil feed hose from the case to the cylinders since it was leaking. There was black engine paint preventing the crush washers from sealing. So I took a look at the engine temperature sensor while the tank was off. I thought I'd clean it up so I unplugged it and then put a socket on it only to find it was loose as hell. I unscrewed it by hand and cleaned it up. Ran it back in and went for a ride and its much much better. It still hiccups a little on low speed stops and transitions but its rideable now. Off hand anyone know how tight/torque the engine temp sensor should be? I snugged it up but I remember Doc saying something about a gap somewhere.

 

Haydnr, I should probably clarify that I changed the base tps calibration to 150,160, and 180(accidently) and the idle readings of 520/530 at around 1100-1200. I might try 165 for a base and see if it helps smooth things out any.

 

Thanks again to everyone, i'm making headway.

[Tom M]

I've been following this thread for a while and whilst I can see in some circumstances the simplified method will work in others it will not. When I am sober I will explain further but in short the tps is a base reference for the fueling and ignition map. If this is not calibrated (zero'd) correctly all the other adjustments may as well be guess work , 520mv,530mv,400mv 600mv at idle is completely irrelevant as the idle can then be incorrectly set (fooled) by altering the air bleed and co trim and once off idle the fuel map will be followed correctly so long as the base setting (150mv) is correct. The fuel map (fuel to air ratio) can be tricked if the tps base setting is altered eg.if the base setting is set high say 300mv fully closed the ecu (map) will deliver more fuel with the butterfly (air) at a lesser degree of opening.

 

All that I can say about this is my base TPS setting is about 250mV, not 150, and I've had my A/F ratio monitored on a dyno and it is right where it should be.

 

You've probably seen this thread before but here's where the "Micha method" was first discussed on this forum:

http://www.v11lemans.com/forums/index.php?showtopic=13188&hl=Micha

 

I would only advocate it for people like me who can't get their bikes to run right using the posted method.

[Tom M]

 

Well my problems just got better. I snugged it up but I remember Doc saying something about a gap somewhere.

 

 

Well that's good news.

 

Be aware that the engine temp holder is real easy to break with very little torque. Snug is good. Don't try to tighten it any more unless you have a spare ready.

[HaydnR]

I've been following this thread for a while and whilst I can see in some circumstances the simplified method will work in others it will not. When I am sober I will explain further but in short the tps is a base reference for the fueling and ignition map. If this is not calibrated (zero'd) correctly all the other adjustments may as well be guess work , 520mv,530mv,400mv 600mv at idle is completely irrelevant as the idle can then be incorrectly set (fooled) by altering the air bleed and co trim and once off idle the fuel map will be followed correctly so long as the base setting (150mv) is correct. The fuel map (fuel to air ratio) can be tricked if the tps base setting is altered eg.if the base setting is set high say 300mv fully closed the ecu (map) will deliver more fuel with the butterfly (air) at a lesser degree of opening.

 

All that I can say about this is my base TPS setting is about 250mV, not 150, and I've had my A/F ratio monitored on a dyno and it is right where it should be.

 

You've probably seen this thread before but here's where the "Micha method" was first discussed on this forum:

http://www.v11lemans.com/forums/index.php?showtopic=13188&hl=Micha

 

I would only advocate it for people like me who can't get their bikes to run right using the posted method.

 

 

I agree the 250mv will make the bike run better using the stock map as it is designed to run on the lean side for emissions. By having the base reference set higher you will achieve a richer mix.

[docc]

The gap in the Engine Temperature Sensor is only an issue if you decide to entirely dismantle the sensor and fabricate a low mass holder. Otherwise, as Tom has said, most important just not to fracture the black plastic.