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Slavomir Musilek (R.I.P.)

how to fool ECU?

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Leo Vince Exhausts and KN filter equals moderate problem at 3000rpm on my lemans 01. After doing TPB (tps set to 150mV; idle running clear at 1200rpm) Bike has fires back to airbox at 3000rpm. No air leak on intake rubbers or exhaust pipes. This symptoms come up only when slowly accelerating up. under hard acceleration or closed throttle nothing happens.

 

This really annoys me especially when cruising in city. What to do? I suggest, if the bike fires to airbox and exhaust, mixture is too lean, thanks to open cans and KN filter. Is there any way how to enrich mixture only in this particular rpms? I am thinkink of getting PC installed but if there is another way I am free for discusion.

 

Slavek

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Leo Vince Exhausts and KN filter equals moderate problem at 3000rpm on my lemans 01. After doing TPB (tps set to 150mV; idle running clear at 1200rpm) Bike has fires back to airbox at 3000rpm. No air leak on intake rubbers or exhaust pipes. This symptoms come up only when slowly accelerating up. under hard acceleration or closed throttle nothing happens.

 

This really annoys me especially when cruising in city. What to do? I suggest, if the bike fires to airbox and exhaust, mixture is too lean, thanks to open cans and KN filter. Is there any way how to enrich mixture only in this particular rpms? I am thinkink of getting PC installed but if there is another way I am free for discusion.

 

Slavek

Does your bike have O2 sensor and catalytic convertor?

What year is bike?

What is TPS reading at idle?

How far out are air bypass screws?

 

To lean it out only in particular rpms you need the PCIII or mapping software.

The air bypass screws effect lower throttle openings.

The "trim", controlled by Axeone or the TechnoResearch VDSTS has a similar effect to the air bypass. How similar? I don't know. I think it effects idle most and then tapers off in effect the further you are from idle....but I am not sure...

Raising the TPS voltage at the potentiometer can trick the engine into thinking the throttle is more open, so it USUALLY, but not always, gives it more fuel....timing is also altered.

It might be worth changing the 150mV to maybe 165mV and see if it behaves better.

But before messing with the TPS voltage, be sure to adjust valves, check settings again, test for back fire, try adjusting bypass screws to a different, probably more closed position, then test for back firing.

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I would be sure to try dialing those air bypass screws in first.

Does idle speed change a lot at various temperatures and riding conditions?

When my bike needs a tuning, I often get a variation in idle speed. Idling in hot weather at a traffic light it will become higher, and coming to a stop from freeway speeds, it will drop to 1000 rpm or lower. Then I know I need to tune it.

Now that I have a wide band oxygen sensor it is easier to set the air bypass. I simply warm up the engine and set A:F to about 13.3:1 I am not sure of the ideal number, but so far that seems to work well. I still have to get the rpm logging working for proper testing...

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PS for whatever it is worth, with my meter A:F was about 13.3:1 at three quarters of a turn out.

TPS is set to 145mV disconnected and 521mV at 1150RPM

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Sure, Idle changes a lot!

 

After 400km on one hit the idle drops to 1000-1100. When cold or after shorter (shorter means 20-120km ride :P ) the idle holds still at 1200-1300.

 

 

three quaters of one turn out? Hm... My three full turns off seems to much! I will close bypass screws a bit and raise idle by left idle screw.

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My bike does sorta the same thing has 3000 rpm hickup and sometime right off idle. Just did a major tune up new air and fuel filters set tps and ballanced carbs by instructions from guzzitech site. Now the odd thing is my rpm rasie, at cold start 1100 stedy, ride 10 miles or so it increases to at least 15 to 1800 rpms. I dont trust my tach cause it wrong and havent had my meter with me on a ride.

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My bike does sorta the same thing has 3000 rpm hickup and sometime right off idle. Just did a major tune up new air and fuel filters set tps and ballanced carbs by instructions from guzzitech site. Now the odd thing is my rpm rasie, at cold start 1100 stedy, ride 10 miles or so it increases to at least 15 to 1800 rpms. I dont trust my tach cause it wrong and havent had my meter with me on a ride.

Some of that idle variation may be the "oil" or engine temperature sensor, and a little variation is normal but I have had success (and failure, so be sure to note what it was set to) changing the throttle bypass screws.

Results are not instantaneous since the change in mixture effects the temperature and vice versa, so test riding may be required between adjustments :bike:

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Some of that idle variation may be the "oil" or engine temperature sensor, and a little variation is normal but I have had success (and failure, so be sure to note what it was set to) changing the throttle bypass screws.

Results are not instantaneous since the change in mixture effects the temperature and vice versa, so test riding may be required between adjustments :bike:

 

I was suspect to temp sensor but havent had time to check to make sure the boots are not craked letting air in. I am leaving next wed for locania bike week so I plan on having it nailed down by then. The hickup deal maybe a little different. the tune up calmed it down by 80% at least I think i will have to spend some real time on that one but any advice will be greatly welcomed.

 

Brent

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Sure, Idle changes a lot!

 

After 400km on one hit the idle drops to 1000-1100. When cold or after shorter (shorter means 20-120km ride :P ) the idle holds still at 1200-1300.

 

 

three quaters of one turn out? Hm... My three full turns off seems to much! I will close bypass screws a bit and raise idle by left idle screw.

Increase tps idle(....say 550mv) with bike balanced, ( idle / 2000-3000 range) and bypasses not open more than 1 full turn....think that will help.Variation at idle is more pronounced when bypasses are open more than one turn

Most of the time hickup from idle to 3000rpm, results from (lean..???) spots where throttle bodies balance is not ok,

and it is more intense for bikes with aftermarket filter /slip on ...etc

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Increase tps idle(....say 550mv) with bike balanced, ( idle / 2000-3000 range) and bypasses not open more than 1 full turn....think that will help.Variation at idle is more pronounced when bypasses are open more than one turn

Most of the time hickup from idle to 3000rpm, results from (lean..???) spots where throttle bodies balance is not ok,

and it is more intense for bikes with aftermarket filter /slip on ...etc

 

I think you are right about that. I have bos slip-ons and the bike hasn't been properly tuned yet. Now I have very nasty hiccup between idle and 3000 rpm. My idle is also too low 800-1000 rpm. I'm afraid I'm gonna fu*k up the bike :(

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you guys,

 

problem solved. Air baypass screws were really opened to much. 3 turns are really a lot :)

I closed bypasses full way, opened them 1 1/2 turn and adjusted by idle screw on the left throttle body. Engine holds still idle at 1100-1200, idle does not drop during rides and firing in 3000rpm has reduced significantly!

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Increase tps idle(....say 550mv) with bike balanced, ( idle / 2000-3000 range) and bypasses not open more than 1 full turn....think that will help.Variation at idle is more pronounced when bypasses are open more than one turn

Most of the time hickup from idle to 3000rpm, results from (lean..???) spots where throttle bodies balance is not ok,

and it is more intense for bikes with aftermarket filter /slip on ...etc

 

I also have mistral slip ons.

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So, I have installed Dynojet and put there more fuel in low and high revs (on track, under full gas around 5000RPM the engine was just like 2stroke). Signaficantlly it has improved! No time for custom map yet but no cranking, no sputtering, no backfire. Even sparks have now the right color :)

 

so Halelůja! One problem down, many more to go :)

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