Need help on fuelling problem

[hendrixgr]

Hi.
I have now reached a point where no one (including all professionals near me) here can help me solve the fuelling problem that i am facing so i will post my problem here in case anyone has ANY idea.
My bike is a gen1 with mcx400 turbo + liquid intercooler plenum running at 12-13 psi which produces 270 hp with a silent full exhaust system.
The fuelling system uses the gen1 ECU along with a split second box in order to control the 4 secondary injectors mounted on the plenum,
a Malpassi 1:1 FPR, a Bosch 044 inline fuel pump and the Honda Firebird injectors.
Everything was working well until one day the bike could not get past 7000 rpm with my AEM failsafe gauge showing an AFR of 18:1 or more.
Back to the tuner where the split second box was tested and found ok, ALL injectors where cleaned at a specialist's shop, FPR was leaky and it was replaced with an Aeromotive 13129 and the 044 fuel pump with the newest Bosch version which is smaller and completely silent.
After a completely new tune the bike made 284 hp and the AFR was spot on except at low rpm (1200 to 4000) where it reaches 10 to 11:1.
My tuner told me that he couldn't make it any leaner than 11:1 something that i don't understand at all since my injectors are only rated at 330 ml.
I personally watched the whole tuning process and i am sure that everything else was working fine.
Where is the problem you may ask, well on the road the AFR is completely off reaching 17:1 at 5000 rpm (6th gear) when accelerating and the bike stalls for a second or two at 7000 rpm until it goes past 8000 where it picks up again with AN AFR OF 12 ~12.8 :1
Btw at lower gears those symptoms do appear also but in a more benign form.
Also the AEM failsafe AFR readings are spot on when compared with he dyno's readings and the stall i am feeling is very real so it is not a failing UEGO sensor.
In the 1st photo you can see this while at 4th gear and in the last one while at 6th gear.
Any ideas or mods (new ecu, power commander etc.) welcomed because at this point my tuner says that the bike works fine on the dyno and the street as he also road tested it (i can testify that on the dyno it works like a dream) but for me it runs like crap on the street not to mention that it burns more fuel cruising that going with 120 miles/h.
Thank you all in advance.
Chris

 

[Telboy2000]

Is the vacuum line to the FPR ok and what pressure is it running at?...could have had a leak in the vacuum line all along during the tuning process.

 

[OZBooster]

what is your tuner using to modify the ecu for the bigger injectors and do you realy need them with secondarys , editor has another set of tables for idle maps , as does woolich

Do you have tps available in the logs ? helps isolate lean due to closing throttle or to pick if a particular tps % is a problem

I agree with Telboy , check your pressure reference source , where and how do you have the regulator connected

 

[hendrixgr]

what is your tuner using to modify the ecu for the bigger injectors and do you realy need them with secondarys , editor has another set of tables for idle maps , as does woolich

Do you have tps available in the logs ? helps isolate lean due to closing throttle or to pick if a particular tps % is a problem

I agree with Telboy , check your pressure reference source , where and how do you have the regulator connected

I will check this today.
Unfortunately the aem failsafe does not log tps but the new logger i got will.
The lean situation is not when i am closing the throttle but while i am at WOT and i can definitely feel the bike stall at 7000 rpm.
My tuner used ecueditor for the Iap and Rpm maps and as i said it rocks on the dyno, it is on the street that it gets lean.
Last night i remapped the split second box and i am also waiting for a pcv to arrive.
I am thinking of getting rid of the split second box and use a pcv (boost based, and a autotune)
Chris

 

[OZBooster]

Will the pcv run the secondarys , i thought they only intercepted the primarys

Microtech works well ,many systems using secondarys use this i believe the newer mcxpress sold in the US uses a microsquirt , they look very capable too
, and seen some use KMS in the Nederlands

 

[hendrixgr]

Will the pcv run the secondarys , i thought they only intercepted the primarys

Microtech works well ,many systems using secondarys use this i believe the newer mcxpress sold in the US uses a microsquirt , they look very capable too
, and seen some use KMS in the Nederlands

Today i understood where is the problem.
The split second box is dead although it communicates with my laptop (i heavily changed it's map but saw no difference)
The tuner tuned the bike without knowing this so i was left with a stock ECU tune which is not boost referenced.
The main difference between the dyno and the road is drag at 200 km/h and up (6k to 8k rpm at 6th) which forces me to open the throttle further which in turn increases boost but at lower rpm (due to heavier load) throwing the tune to the garbage bin.
This explains also why this problem appears more subtle the lower the gear i am in.
Of course all those are theoretical until i get hold of the pcv and start experimenting a bit.
I am thinking to use either the pcv with boost reference + secondary injector module + autotune or save money and get me a DTA S60 with bigger injectors.
Chris

 

[hendrixgr]

Is the vacuum line to the FPR ok and what pressure is it running at?...could have had a leak in the vacuum line all along during the tuning process.

I did checked this today and the fuel pressure is constant at 43 psi + boost psi so the fuel system works ok.
After all everything is new...
The only thing left is to find out the max hp supported by the firebird injectors i have (330 cc), maybe they are enough for 280 hp which i think are too much for the street.
Maybe i should lower the boost a little.
Chris

 

[hendrixgr]

One final question.
Does anyone knows if i can use the power commander sfm (secondary fueling module) in a gen1 in order to control the plenum injectors?
I can't imagine why not, maybe the ĉonnetors are different...
I am asking because everyone selling the sfm module states that it is intended for the gen2 not the gen1.
Chris

 

[OZBooster]

on a gen 2 the ecu sets when and how long the secondarys turn on, you on the other hand will be trying to use the primary signal to run both primarys and secondarys , effectively same as one big set of injectors but needing 2 PC's to run
your better off either getting bigger primary injectors and using only them with boost referenced PC or finding a new secondary controller

and finding another tuner , he should have stopped when the secondarys were not responding , its a wonder your bike is not hurt running as it was

 

[hendrixgr]

on a gen 2 the ecu sets when and how long the secondarys turn on, you on the other hand will be trying to use the primary signal to run both primarys and secondarys , effectively same as one big set of injectors but needing 2 PC's to run
your better off either getting bigger primary injectors and using only them with boost referenced PC or finding a new secondary controller

and finding another tuner , he should have stopped when the secondarys were not responding , its a wonder your bike is not hurt running as it was

You are absolutely correct, luckily the bike is in excellent condition.
The only problem is that the only option here is to try to tune the bike my self.
I will start with a pcv (boost referenced), an autotune module and maybe s2000 injectors.
Chris

 

[OZBooster]

get yourself injectors capable of 400hp, as you should be around 300-330hp now
that will take at least 500cc/cyl

Just guessing here but maybe your dyno guy had wheelspin he had not noticed , unloading the bike and reducing its fuel needs and output

maybe plan on the 650cc injectors that are readily available to suit busa if your not able to adapt something else

 

[Quiksilver]

If I remember. Orrectly auto tune and turbos don't like each other don't quote me though. From what I hear many people use micro tech as a secondary fuel controller.

 

[hendrixgr]

get yourself injectors capable of 400hp, as you should be around 300-330hp now
that will take at least 500cc/cyl

Just guessing here but maybe your dyno guy had wheelspin he had not noticed , unloading the bike and reducing its fuel needs and output

maybe plan on the 650cc injectors that are readily available to suit busa if your not able to adapt something else

Well the problem is that i don't trust them 100% any more...
Can you elaborate on the injectors?
What injectors are drop in replacements for the gen1 hayabusa and where can i find them?
Of course i am responsible for my decisions so don't worry if you suggest something.
I am looking for something that will maintain low rpm performance unlike now that fuelling from 1200 to 3500 rpm is all over the place.
Chris

 

[hendrixgr]

If I remember. Orrectly auto tune and turbos don't like each other don't quote me though. From what I hear many people use micro tech as a secondary fuel controller.

From my ongoing search it looks like it will work if the whole setup is boost based and the ecu tune is close enough.
In any case my option are limited so i will give it a try anyway.
Chris

 

[OZBooster]

personally i would get another secondary controller and keep the rest of the system you have , using standard size primarys

do you currently have the honda injectors on the primarys with something else on secondarys or standard primarys with honda in secondarys

lots of resellers have big injectors to fit if you want to go that way , try Frank or Rob on the forum ,

 

[hendrixgr]

personally i would get another secondary controller and keep the rest of the system you have , using standard size primarys

do you currently have the honda injectors on the primarys with something else on secondarys or standard primarys with honda in secondarys

lots of resellers have big injectors to fit if you want to go that way , try Frank or Rob on the forum ,

I have the honda on the primaries and 450cc injectors on the plenum.
Anyway i got a set of S2000 for 100 dollars in order to try them with my pcv which is connected to a 2 bar MAP sensor, i think that s2000
injectors might be enough for the 280 rwp the engine produces right now.
Btw i would feel more comfortable if i lower the power to say 250 hp, i think 280 are too much for the street.
Do you think that a microtech mt2 would work in case i retain the plenum injectors?
Somehow i find the split second box difficult to adjust...
Chris

 

[OZBooster]

MT2 would be great on the secondarys , , but be aware you need a microtech specific communication dongle to program it
and maps are not internet exchangable you can only load a saved map from your or someone elses dongle
if you want to compare to another microtech map take a screen shot

 

[hendrixgr]

MT2 would be great on the secondarys , , but be aware you need a microtech specific communication dongle to program it
and maps are not internet exchangable you can only load a saved map from your or someone elses dongle
if you want to compare to another microtech map take a screen shot

I will try the s2000 stand alone injectors first as i have all the parts and if not successfull then i will go the microtech way.
Chris

 

[hendrixgr]

Well after some thought i decided to build my own secondary injector controller in order to use it in case i go back to plenum injectors.
I have been designing things for a living all my life so it is time for me to build something for me only...
It shouldn't cost more than 50 dollars and some of my free time.
Chris

 

[hendrixgr]

As a footnote i did disconnect the split second box and saw absolutely no difference which almost proves that it is damaged but i need to check if the injectors are
1) electrically connected
2) are receiving fuel.
I feel more confident now that i will fix the problem.
Thank you all for your valuable help!
Chris