Fluctuating A/R

[Snowyone]

I've been struggling with an air leak on the throttle body of my 124 build. I kept thinking it was the seals between the manifold and heads but now think it might be one of the components on the throttle body. I have a Power Vision that allows me to keep track of the A/R. On the way Hm from the tuner a couple days ago I was maintaining the 13 to 14.7 ratio when all the sudden it went lean recording in the 20's and running crappy. I limped Hm and figured it was a manifold seal spraying carb clean in that area. Put in new seals and 300 miles later the same thing again. Long way from Hm and stopped for a nature call. Started back up and A/R was fine for about 60 miles and then ran rich 11 to 12.5 till I stopped for fuel. Then ok for 40 miles then lean in the 15 to19 range. Lots of elevation change from 2k to 6k and temps from 80+ to 50. I've about got the bolts worn out taking the fuel tank and TB off and on. Anyone have some advice?  It's an HPI 58 mm with a 62mm manifold and stock HD sensors. Help!

[strokerjlk]

More info .
What cal is it . Year model bike .
Can you post the map ?
Several things to look at and consider .

[Admiral Akbar]

Also

Has it always had this issue since assembly?

Max

[strokerjlk]

One thing to consider is. Your PV is monitoring desired Afr .
It isn't reporting actual Afr . So if you see diff Afr's displayed , it is what the ECM is calling for . (whatever  is set in that area of the Afr table within your map )

[Snowyone]

It's a 2011 Fatboy. I'm limited to my iPad being 3k miles from Hm so can't download. I'll get ahold of tuner but was having the problem before and thought we had it fixed.  Was wondering about the map sensor and if it could be the culprit?
Max, it ran fine for about 3k which was last fall. It started running lean then but was put to bed here in Az while I went Hm  to Ak.  I came back the first of Mar and did a piston swap for more compression as was not happy with performance of initial build. Took a couple of tries to get the manifold to seal but thought I had it and took it to Phoenix for a dyno tune. Worked great and was happy with output for about 300 miles and suddenly lean again and the story from the first post. Waiting for a reply from the tuner for his input but haven't heard yet.

[Snowyone]

I was confused on what I was reading then. I thought the PV was reading actual. When Ron tuned it he told me the readout should stay between 13 and 14.7 which it did for about 300 miles and then I don't know what happened. Running crappy numbers all over.

[strokerjlk]

I was confused on what I was reading then. I thought the PV was reading actual. When Ron tuned it he told me the readout should stay between 13 and 14.7 which it did for about 300 miles and then I don't know what happened. Running crappy numbers all over.

That is correct it should . Your richest settings of 13.0 would be on decel and wot
The leanest would be cruise .

[rageglide]

Sounds like Adaptive behavior to me.  Obviously the tuners would know this far better than a shade tree guy like myself.

You could pick up the Autotune module with wide bands and connect it to the PV.  This would allow you to log the actual AFRs according to the O2s.  That's what really matters.

Seems like that 20:1 ratio you see may correspond to a VE table that's mapped far too rich and the ECM is pulling fuel to meet the value actual target?  But that would also imply you are in closed loop for that map/rpm.

[strokerjlk]

Sounds like Adaptive behavior to me.  Obviously the tuners would know this far better than a shade tree guy like myself.

You could pick up the Autotune module with wide bands and connect it to the PV.  This would allow you to log the actual AFRs according to the O2s.  That's what really matters.

Seems like that 20:1 ratio you see may correspond to a VE table that's mapped far too rich and the ECM is pulling fuel to meet the value actual target?  But that would also imply you are in closed loop for that map/rpm.

I can't see how a PV would display 20:1 Afr . That's what has me puzzled .
Sounds exactly like adaptive  control . Except it should never show anything leaner than 14.6 or 14.7 depending on the what value is entered in the table to enable closed loop.
The 11's and 12's is very possible . If the motor is going really lean, it will go into distress mode and start calling for 2-3 Afr richer than what the Afr table is set at .
The 20:1 is what has me stumped . You can't take a PV afr table beyond 18:1 as far as I have seen. But since the tuner said between 13:1 and 14.7:1 I doubt very seriously he would have set a custom Afr table up beyond 14.7 anyway .
 

[rbabos]

Only takes a second to reset fuel trims and disable adaptive, then do a run to compare.
Ron

[rageglide]

I can't see how a PV would display 20:1 Afr . That's what has me puzzled .
Sounds exactly like adaptive  control . Except it should never show anything leaner than 14.6 or 14.7 depending on the what value is entered in the table to enable closed loop.
The 11's and 12's is very possible . If the motor is going really lean, it will go into distress mode and start calling for 2-3 Afr richer than what the Afr table is set at .
The 20:1 is what has me stumped . You can't take a PV afr table beyond 18:1 as far as I have seen. But since the tuner said between 13:1 and 14.7:1 I doubt very seriously he would have set a custom Afr table up beyond 14.7 anyway .

Yeah I can't imagine it has AFR set above 14.7 at all.  Maybe in the light load cruise, but why...  And can't figure out where the 20:1 came from.  I can't look at logs on this computer at the moment, otherwise Id look over the complete list of available info. 

Certainly if the NB was reading the mixture and it came up with 20:1 I'm thinking it's useless info.  But who knows.  WB set up would tell truth in a log file.  I wish we could use the WBs with the PV to actually RUN on the WBs.... but that's probably too threatening to the aftermarket industry, I could be totally off base on that...   

[Snowyone]

I do have the WB sniffers and auto tune and when I see the real lean readings it's on decel on steeper mountain grades here in Az. I'm thinking it must be a sensor problem but wouldn't or shouldn't it show up as a DTC?  I'm going to head to a dealer and see if they can read the history and see if something shows.

[strokerjlk]

I've been struggling with an air leak on the throttle body of my 124 build. I kept thinking it was the seals between the manifold and heads but now think it might be one of the components on the throttle body. I have a Power Vision that allows me to keep track of the A/R. On the way Hm from the tuner a couple days ago I was maintaining the 13 to 14.7 ratio when all the sudden it went lean recording in the 20's and running crappy. I limped Hm and figured it was a manifold seal spraying carb clean in that area. Put in new seals and 300 miles later the same thing again. Long way from Hm and stopped for a nature call. Started back up and A/R was fine for about 60 miles and then ran rich 11 to 12.5 till I stopped for fuel. Then ok for 40 miles then lean in the 15 to19 range. Lots of elevation change from 2k to 6k and temps from 80+ to 50. I've about got the bolts worn out taking the fuel tank and TB off and on. Anyone have some advice?  It's an HPI 58 mm with a 62mm manifold and stock HD sensors. Help!

Makes sense now . But you didn't say that in your OP