TPS and tuning

[PhillipLarsen]

Update. I did not hear anything back from HMB after I advised them that the cam chain tensioner does not fit my 2004 Ballabio. 
Wanting to take advantage of the riding season I went ahead with using the HMB tensioner wear pad and spring on my original tensioner base. The pad is near identical and the spring as well The HMB spring had a little more resistance than the original, likely because it is new. They look identical. 
I reassembled the bike, using new metal gasket on timing case, hoping to again have an oil tight bike. 
Ran the bike, checked spark scatter at idle and the 1750 to 2000 rpm range. Very slightly less scatter but maybe 20% less.
Took bike for a test ride. Same issue of popping back into air box at that rpm range whether riding or in my stand. 
I am now convinced this is not the issue causing misfire / popping into air box.
I set everything back to Decent tuneup setting 157mv, balanced TBs, CO =0, air screws 1 turn out, idle 1250. 
Extensive test in stand ( use my Hartzel dyno cooling fan) and riding showed missing and popping back into air box in the 1500 to 2800 rpm range (larger range than previous), plugs showing white / very lean indication. 
Also ran test in stand on left cylinder only and right cylinder only. Same problem both sides. 
There are no leaks on intake or exhaust. 
All sensors are new, plugs, etc. 
In desperation I decided to see if increase TPS setting would help.

i did it initially in large increments to see if changed. Without going through all the steps which was spread out over 2 days I found as I increased the TPS setting the range of rpm where missing and popping got tighter until it was only at 1950 RPM. One more increase and it was gone. I then worked back down until it started and went up in small increments until it stopped. Took numerous rides attempting to get it to pop or miss. It doesn’t now, no matter what I try. 
The end setting that makes it run so nice  with as low as I can set it with out inducing popping is 

TPS 285 mv, balanced TBs, air screws 1/2 out, idle 1250 RPM. Plugs show medium tan at various rpm runs. 
It doesn’t make sense to me that this works. 
Could it be fuel pump pressure? Or injector condition?

I am very pleased to have it running so fine, and not worrying it may pop and stall when making a left turn across traffic at low rpm, but would really like to understand if something is not correct  

I have put on about 300 km now and it continues to run perfectly. Will be checking fuel consumption to compare to previous levels. 

I would really appreciate input from others that may have any ideas. 
 

[Pressureangle]

53 minutes ago, PhillipLarsen said:

Update. I did not hear anything back from HMB after I advised them that the cam chain tensioner does not fit my 2004 Ballabio. 
Wanting to take advantage of the riding season I went ahead with using the HMB tensioner wear pad and spring on my original tensioner base. The pad is near identical and the spring as well The HMB spring had a little more resistance than the original, likely because it is new. They look identical. 
I reassembled the bike, using new metal gasket on timing case, hoping to again have an oil tight bike. 
Ran the bike, checked spark scatter at idle and the 1750 to 2000 rpm range. Very slightly less scatter but maybe 20% less.
Took bike for a test ride. Same issue of popping back into air box at that rpm range whether riding or in my stand. 
I am now convinced this is not the issue causing misfire / popping into air box.
I set everything back to Decent tuneup setting 157mv, balanced TBs, CO =0, air screws 1 turn out, idle 1250. 
Extensive test in stand ( use my Hartzel dyno cooling fan) and riding showed missing and popping back into air box in the 1500 to 2800 rpm range (larger range than previous), plugs showing white / very lean indication. 
Also ran test in stand on left cylinder only and right cylinder only. Same problem both sides. 
There are no leaks on intake or exhaust. 
All sensors are new, plugs, etc. 
In desperation I decided to see if increase TPS setting would help.

i did it initially in large increments to see if changed. Without going through all the steps which was spread out over 2 days I found as I increased the TPS setting the range of rpm where missing and popping got tighter until it was only at 1950 RPM. One more increase and it was gone. I then worked back down until it started and went up in small increments until it stopped. Took numerous rides attempting to get it to pop or miss. It doesn’t now, no matter what I try. 
The end setting that makes it run so nice  with as low as I can set it with out inducing popping is 

TPS 285 mv, balanced TBs, air screws 1/2 out, idle 1250 RPM. Plugs show medium tan at various rpm runs. 
It doesn’t make sense to me that this works. 
Could it be fuel pump pressure? Or injector condition?

I am very pleased to have it running so fine, and not worrying it may pop and stall when making a left turn across traffic at low rpm, but would really like to understand if something is not correct  

I have put on about 300 km now and it continues to run perfectly. Will be checking fuel consumption to compare to previous levels. 

I would really appreciate input from others that may have any ideas. 
 

I sent the injectors from my '97 out to be cleaned, turned out they were *very* dirty, so much so that I had to remap the entire fuel curve because it went rich. iirc the left injector was down 6% and the right down 10%. So yes, the injectors can, and over time certainly will, lean the mixture. On modern auto, the system accomodates injector change by increasing the pulse width to keep the O2 sensor happy. On ours, well, I don't know when or if the factory started running the fuel from the O2 sensor. My first V11 is still on the bench with the stock ECU so I'm sure I'll be revisiting some of these questions in the coming months. 

[Lucky Phil]

3 hours ago, PhillipLarsen said:

Update. I did not hear anything back from HMB after I advised them that the cam chain tensioner does not fit my 2004 Ballabio. 
Wanting to take advantage of the riding season I went ahead with using the HMB tensioner wear pad and spring on my original tensioner base. The pad is near identical and the spring as well The HMB spring had a little more resistance than the original, likely because it is new. They look identical. 
I reassembled the bike, using new metal gasket on timing case, hoping to again have an oil tight bike. 
Ran the bike, checked spark scatter at idle and the 1750 to 2000 rpm range. Very slightly less scatter but maybe 20% less.
Took bike for a test ride. Same issue of popping back into air box at that rpm range whether riding or in my stand. 
I am now convinced this is not the issue causing misfire / popping into air box.
I set everything back to Decent tuneup setting 157mv, balanced TBs, CO =0, air screws 1 turn out, idle 1250. 
Extensive test in stand ( use my Hartzel dyno cooling fan) and riding showed missing and popping back into air box in the 1500 to 2800 rpm range (larger range than previous), plugs showing white / very lean indication. 
Also ran test in stand on left cylinder only and right cylinder only. Same problem both sides. 
There are no leaks on intake or exhaust. 
All sensors are new, plugs, etc. 
In desperation I decided to see if increase TPS setting would help.

i did it initially in large increments to see if changed. Without going through all the steps which was spread out over 2 days I found as I increased the TPS setting the range of rpm where missing and popping got tighter until it was only at 1950 RPM. One more increase and it was gone. I then worked back down until it started and went up in small increments until it stopped. Took numerous rides attempting to get it to pop or miss. It doesn’t now, no matter what I try. 
The end setting that makes it run so nice  with as low as I can set it with out inducing popping is 

TPS 285 mv, balanced TBs, air screws 1/2 out, idle 1250 RPM. Plugs show medium tan at various rpm runs. 
It doesn’t make sense to me that this works. 
Could it be fuel pump pressure? Or injector condition?

I am very pleased to have it running so fine, and not worrying it may pop and stall when making a left turn across traffic at low rpm, but would really like to understand if something is not correct  

I have put on about 300 km now and it continues to run perfectly. Will be checking fuel consumption to compare to previous levels. 

I would really appreciate input from others that may have any ideas. 
 

You'd be better off just adjusting the CO as a quick and dirty way to control the popping rather than the Tps sensor. The CO setting affects the whole range but is most effective at the bottom. 

Phil 

[docc]

12 minutes ago, Lucky Phil said:

You'd be better off just adjusting the CO as a quick and dirty way to control the popping rather than the Tps sensor. The CO setting affects the whole range but is most effective at the bottom. 

Phil 

Agreed. The TPS indexes 'the map" to the entire rpm range.  Not the best place to compensate for some other shortcoming.

Sure, the "shortcoming" could be compromised injectors. May I ask if both the fuel and air filters have been renewed?

[pete roper]

There is also the problem of wear simply due to age and use. As the spindle bushes wear the plates will settle in the chokes carving out the edge of the TB and wearing the plate. This means that more air can move past the plate so the mixture goes lean. This is mainly an issue at idle and leads to spitting back through the inlet tracts and this exacerbates the problem and increases the wear. It’s something I’m very aware of because the big 50mm TB’s on the 8V’s are particularly susceptible to it and it’s a king sized PITA.

The larger the choke the worse the problem becomes. I can’t remember what size the TB’s are on the V11’s but I seem to remember that they actually downsized them for the early 2 valve CARC bikes and they are not nearly as prone to showing unacceptable behaviour as they age compared to the 8V’s. If, as I suspect, the V11 TB’s have larger chokes then one would have to think that they would be more prone than the early CARC bikes to ‘Air Leakage’ but not as bad as the 8V items. If I’m correct in that it would perhaps explain part of the problem at least.

At the end of the day if more fuel is required at a certain engine speed and throttle position by far the best way to achieve it would simply be to add more in those cells in the map rather than kludgeing it with the CO trim or buggering about with the TPS.

[Lucky Phil]

I think they are 40mm Pete from memory. The MGS-01s were 45 I think. Add the throttle shaft bush wear as well. When I got the Daytona engine running I thought I had valve tapping noise on the r/h cylinder at idle until I touched the butterfly shaft on the r/h TB and it stopped taping in time with the intake pulses. This led to rebuilding the TB's

Phil 

[PhillipLarsen]

Thanks Docc, Peter and Phil for your advice. Will do more checking to try corner the issue.

The air filter is new, but fuel filter is not. I just happen to have a new one on the shelf so I will ride out the full tank of fuel in next couple days, pull the tank off and change it, see if any change by setting TPS back to 157 mv and trying it. 
The TB shafts do not feel like they have any play ( bike has just approx 26,000 kms on it). 
I use short bolts with copper washers to close off vacuum nipples holes when not in use. 

[Pressureangle]

12 hours ago, Lucky Phil said:

I think they are 40mm Pete from memory. The MGS-01s were 45 I think. Add the throttle shaft bush wear as well. When I got the Daytona engine running I thought I had valve tapping noise on the r/h cylinder at idle until I touched the butterfly shaft on the r/h TB and it stopped taping in time with the intake pulses. This led to rebuilding the TB's

Phil 

Since it's right at hand, my 2000 v11 bodies are (actual) 44.68mm vertical and 44.71mm horizontal at the inlet.

Edited June 13 by Pressureangle

[pete roper]

5 hours ago, Pressureangle said:

Since it's right at hand, my 2000 v11 bodies are (actual) 44.68mm vertical and 44.71mm horizontal at the inlet.

That’s what I thought. Nominal 45mm on the V11. CARC 2-valve motors use 40’s from memory and the 1200’s use 50’s. When they went to the 1400 they went single 54mm body with ride by wire control.

Mark, (Beetle.) has converted his Griso which runs a big port single spark version of the motor that we built for him to a single mechanical TB, I think it’s a 60mm? Not absolutely sure. Had to go to higher flow injectors too as boy does it like the dinosaur juice!

[audiomick]

6 hours ago, Pressureangle said:

... 44.68mm vertical and 44.71mm horizontal ...

What? They're out of round? I'm shocked and dismayed!!! 

[Pressureangle]

3 hours ago, audiomick said:

What? They're out of round? I'm shocked and dismayed!!! 

Well...to be fair, could have been my badly angled wrists leaning over the tools I should have put away while the lift is at full height.

[PhillipLarsen]

And thanks @Pressureangle, I will get the injectors serviced at next opportunity when can have the bike down without affecting my riding plans, just to ensure there are no hidden issues. 
There are several companies that service gas fuel injectors here in the Vancouver area. 

[PhillipLarsen]

Update. Still waiting  for a new  fuel pump to tank gasket so can change the fuel filter, and will get injectors serviced at end of riding season. 
In the mean time riding the Ballabio a lot and running perfect with the TPS at 285. 
Looking back at my notes I had measured the original TPS factory setting ( still had yellow seal on screw heads) at 330 mv from factory with everything disconnected.before changing the TPS. Some could be due to wear I suppose.  Did anyone ever check one fresh near new to see what was actually being delivered back in 2004?

[gstallons]

Nope...... or prolly not.

[docc]

 I might suggest that having to set the TPS very differently from the baseline (indexing the fuel/ignition map randomly) could indicate that some other parameter in the system is faulty. Perhaps a CO Fuel Trim setting far from zero. Or a sensor out of range.

Guzzidiag is valuable for assessing these readings and their responsiveness as the engine warms.  A way to see what the ECU is seeing . . .