Running lean

[ficohifi]

Hi,
Filip here.

I have 2002. model without modification. All is stock.
It seems that engine running lean on idle and first 1/4 of throtlle.
On begining to write, this problem is very small, motor is good for driving, but drive and engine breaking is not smooth as I suppouse can be.
If I disconnect MAP sensor engine sound perfect. I suspect on MAP sensor but on idle output voltage is 2.583V
I cross examine IAP and AP by connectong both in same time and change input pressure. Both have same output changes almost in 1/1000 V. All is in manual's specification.It would be considered that both sensors are good.
TPS and STPS are set as described in manual (voltage values 1.1 and 0.8 for closed pisitions)
Idle is set on 1100rpm.
PAIR is blocked with plates.
IAT sensor is ok.
Oil temp. sensor is ok.
Throtlle bodies are syncronised with Morgan Carb Tune Pro in 1 mm tolerance.
Spark plugs are light brown color. All are same color.
Injectors are clean. For any xase it put in ultrasonic bath with signal generator 16Hz, 16% duty cicle to simulate 2000rpm, 10ms opening for best effect.
Fuel consumption for cool driving is 5-5.5 litres on 100km.
Because all parts are good and all settings are (I can say) perfect, I can not do anything else.

After all, just for test I though how to enrich mixture on easiest way on small throtlle, but not on another part and got perfect result.

My plan was to lowering vacuum (rising pressure) for MAP sensor only slight. I put Y connection on vacuum hose for MAP sensor. On side connection I put flow regulator to take filtered air from airbox to lowering vacuum. I use airbox connection place for PAIR. Hose which I use is 4mm inside diameter and some metal capilar tube 1.5mm inside to make joints part. Air flow regulator is multiturn for 6mm hose. Totally 12 turns. I start from totaly closed. It needs only 1 and 1/4 turns.
This little air make difference on small throtlle openings but no effect on middle and upper half.
This is exactly what I want to get.
It work perfect.
I check agaim spark plugs. Color is same, light brown.
Fuel consumption stay same.
After all I suspect in fuel quality in my country, Serbia.
Just for information, I had problem like this with Bandit 1200 2003. with carburetors. It run in lean mixture on idle and lower part of throtlle. There was  little detonations inside rubber connection carburetors-cylinder head. It was impossible to adjust with pilot screw and jet needle hight. TPS moving forward make some results, but ruine smooth drive feeling. After all attempts, on the end I changed pilot jet to #22.5(0.45mm)(originaly was #15(0.375mm)) and got perfect mixture for 2 3/4 turns.
This may be interesting for someones.

If someone have simmilar situation with GSX1400 , it would be great to hear another experience.

Regards.

[Eric GSX1400K3]

Hey Fico, welcome along, geat info. I also have a K3 (technically a K2 as its December 2002 build) i also have low speed stumble / poor running. I have changed MAP sensor with new, and new TPS and STPS.   

Your measurements seem right re fuel consumption, typical for these engines. Same with TPS and STPS, the open and closed values respectively are what matters.

You may want to check TPS values between #1-2 and #3-4, as the connection is via 2 screws held by springs, if one is loose, then the butterflies on 1-2 open earlier than 3-4, causing a hesitation in pick up from a closed throttle.

They are not real fussy on fuel type, I run on 91RON, but then I dont know if Serbian unleaded would be the same RON value or if it has more sulfur in it.

There's no point in running a higher octane unless its turbo charged or dyno tuned.

Your lowering vacuum trick is clever. Do you have any part numbers or any photos you can share?

 

[ficohifi]

Hi,
Filip here.

I have 2002. model without modification. All is stock.
It seems that engine running lean on idle and first 1/4 of throtlle.
On begining to write, this problem is very small, motor is good for driving, but drive and engine breaking is not smooth as I suppouse can be.
If I disconnect MAP sensor engine sound perfect. I suspect on MAP sensor but on idle output voltage is 2.583V
I cross examine IAP and AP by connectong both in same time and change input pressure. Both have same output changes almost in 1/1000 V. All is in manual's specification.It would be considered that both sensors are good.
TPS and STPS are set as described in manual (voltage values 1.1 and 0.8 for closed pisitions)
Idle is set on 1100rpm.
PAIR is blocked with plates.
IAT sensor is ok.
Oil temp. sensor is ok.
Throtlle bodies are syncronised with Morgan Carb Tune Pro in 1 mm tolerance.
Spark plugs are light brown color. All are same color.
Injectors are clean. For any case it put it in ultrasonic bath with signal generator 16Hz, 16% duty cicle to simulate 2000rpm, 10ms opening for best effect.
Fuel consumption for cool driving is 5-5.5 litres on 100km.
Because all parts are good and all settings are (I can say) perfect, I can not do anything else.

After all, just for test I though how to enrich mixture on easiest way on small throtlle, but not on another part and got perfect result.

My plan was to lowering vacuum (rising pressure) for MAP sensor only slight. I put Y connection on vacuum hose for MAP sensor. On side connection I put flow regulator to take filtered air from airbox to lowering vacuum. I use airbox connection place for PAIR. Hose which I use is 4mm inside diameter and some metal capilar tube 1.5mm inside to make joints part. Air flow regulator is multiturn for 6mm hose. Totally 12 turns. I start from totaly closed. It needs only 1 and 1/4 turns.
This little air make difference on small throtlle openings but no effect on middle and upper half.
This is exactly what I want to get.
It work perfect.
I check agaim spark plugs. Color is same, light brown.
Fuel consumption stay same.
After all I suspect in fuel quality in my country, Serbia.
Just for information, I had problem like this with Bandit 1200 2003. with carburetors. It run in lean mixture on idle and lower part of throtlle. There was  little detonations inside rubber connection carburetors-cylinder head. It was impossible to adjust with pilot screw and jet needle hight. TPS moving forward make some results, but ruine smooth drive feeling. After all attempts, on the end I changed pilot jet to #22.5(0.45mm)(originaly was #15(0.375mm)) and got perfect mixture for 2 3/4 turns.
This may be interesting for someones.

If someone have simmilar situation with GSX1400 , it would be great to hear another experience.

Regards.

[ficohifi]

Hi,
Filip here.

I have 2002. model without modification. All is stock.
It seems that engine running lean on idle and first 1/4 of throtlle.
On begining to write, this problem is very small, motor is good for driving, but drive and engine breaking is not smooth as I suppouse can be.
If I disconnect MAP sensor engine sound perfect. I suspect on MAP sensor but on idle output voltage is 2.583V
I cross examine IAP and AP by connectong both in same time and change input pressure. Both have same output changes almost in 1/1000 V. All is in manual's specification.It would be considered that both sensors are good.
TPS and STPS are set as described in manual (voltage values 1.1 and 0.8 for closed pisitions)
Idle is set on 1100rpm.
PAIR is blocked with plates.
IAT sensor is ok.
Oil temp. sensor is ok.
Throtlle bodies are syncronised with Morgan Carb Tune Pro in 1 mm tolerance.
Spark plugs are light brown color. All are same color.
Injectors are clean. For any case it put it in ultrasonic bath with signal generator 16Hz, 16% duty cicle to simulate 2000rpm, 10ms opening for best effect.
Fuel consumption for cool driving is 5-5.5 litres on 100km.
Because all parts are good and all settings are (I can say) perfect, I can not do anything else.

After all, just for test I though how to enrich mixture on easiest way on small throtlle, but not on another part and got perfect result.

My plan was to lowering vacuum (rising pressure) for MAP sensor only slight. I put Y connection on vacuum hose for MAP sensor. On side connection I put flow regulator to take filtered air from airbox to lowering vacuum. I use airbox connection place for PAIR. Hose which I use is 4mm inside diameter and some metal capilar tube 1.5mm inside to make joints. Air flow regulator is multiturn for 6mm hose. Totally 12 turns. I start from totaly closed. It needs only 1 and 1/4 turns.
This little air make difference on small throtlle openings but no effect on middle and upper half.
This is exactly what I want to get.
It work perfect.
I check agaim spark plugs. Color is same, light brown.
Fuel consumption stay same.
After all I suspect in fuel quality in my country, Serbia.
Just for information, I had problem like this with Bandit 1200 2003. with carburetors. It run in lean mixture on idle and lower part of throtlle. There was  little detonations inside rubber connection carburetors-cylinder head. It was impossible to adjust with pilot screw and jet needle hight. TPS moving forward make some results, but ruine smooth drive feeling. After all attempts, on the end I changed pilot jet to #22.5(0.45mm)(originaly was #15(0.375mm)) and got perfect mixture for 2 3/4 turns.
This may be interesting for someones.

If someone have simmilar situation with GSX1400 , it would be great to hear another experience.

Regards.