starting the bike

[gtecomp]

Hello there,

 

This days I resurected an old project. GSXR 750 '88 EFI  turbo. I've made the conversion to EFI before 7 years. In simple words - bike is not fired since then. Somewhere thru years, the ECU was sold (it was Link G4 Atom) and I don't remember why, but probably it should be like this!. So universe flip and previous  week I receive unbearable desire to revive the bike. I bought MaxxECU Mini (the cheapest ECU on market...I never liked MegaSquirt), re-pin the new connector, somehow found the old Link file (revive old laptop as far I have stolen the RAM from it) and put the basic data like: trigger angle, type of sensors and injectors.

Yesterday I was able to start the bike (7 years ....not even cranked) and tune some basic thinks. But as far as I remember even whit old ECU , starting from cold was not easy.

 

If you put to much cranking fuel and warm up..it will flood...if opposite  - won't start stable and repeatable.

 

So basic data of the bike...noting fancy.

GSXR 750 bone stock, but low millage, less 15 000km

GSXR 600 TB with stock inj#

COP aka pencil coils

BOSCH 044 pump

fast idle lever - rise Thothle around 1%

wasted spark

injection is ...all 4 injectors together every 720 deg.

 

I wonder ...

 

should  I put cam sync sensor and make sequentional inj and spark?

can you share your experiance with cold start of your bikes?

Any tricks from the sleeve ?

 

Regards

  

 

 

[Arttu]

Well, few things that I have learned from EFI conversion projects:

• Crank triggering issues. Most common reason for difficult starting is slow or erractic crank position decoding. So I would try to analyze the logs and see how quickly you get the correct rpm and if there are any rpm errors during cranking.
• Slightly related, it's worth of checking if the ignition timing matches to what you are trying to command during cranking. And naturally commanded timing should at right ballpark, 0-10 degrees usually work fine. Also make sure that you are using correct dwell settings and you get proper sparks.
• After the basics above are in order it's mostly about correct amount of fuel. There one key thing is to use the right settings for right part of the starting process. Cranking fuel affects mainly for cranking and the few very first firing cycles. Once it picks up the rpm it's mainly after start enrichment combined with warmup enrichment. Warmup handles the part after the idle has somewhat stabilized. Usually it's better to start with lower values to avoid flooding the engine and increase fuel slowly as needed.
• Sequential or batch injection shouldn't matter much. Or let's say it other way around: sequential injection with correct timing may improve starting but there shouldn't be any problem to get good starting with batch injection.
• Some fast idle or opening the throttle is usually needed to get it started from cold. Quite often it will fire up with closed throttle but it won't stay running without extra air. Relating to this, if the engine hasn't started after few seconds of cranking usually it has already got too much fuel and then opening the throttle often helps.  

[gtecomp]

yep there is some sync lost errors in every starting. I'm using:

-  12-1 trigger

-stock VR sensor

 

...Should I go to Hall sensor? 

[gtecomp]

 

 

runs fine otherwise

[Arttu]

Haven't tried it specifically with MaxxECU but with some other ECUs 12-1 has been kind of borderline case for reliable starting. Works on some and gives troubles on others. I'm currenlty using 24-2 as default option and it has been trouble free by this far.

Stock VR sensor should be fine. Of course it's possible that it just doesn't give strong enough signal at low rpm. You can try to eliminate this by adjusting the sensor closer to the wheel or playing with arming voltage and other trigger settings on the MaxxECU. But my guess is that the crank speed just varies too much between the teeth and the ECU can't always detect the missing tooth.

[gtecomp]

arming voltage is pretty low.  But I'll try lower. Thanks for advices  Mr.Arttu.

[Fredrik_Steen]

I needed to change sensor on my maxxecu gsx-r 1100. We couldn't find Zero-crossing with stock sensor. Maxxecu support tried but with no luck.

 

 

[gtecomp]

Hm...this MaxxECU can work with original trigger wheel...interesting 

[gtecomp]

How you connect with MaxxECU support. I've tried ,but they want some code written on ECU to verified that your are actual owner??? I've checked both ECU's and can't find some S/N or code. There is some small bar code ,but is so badly printed, that make imposiblle to be read.

 

 I still mapping my VTR1000 and have some questions to be answered...

[gtecomp]

found some old videos with Link ECU....video taken with Iphone4   . Obviously a lot of time is past away, since now there is iphone 13 :):):)

[Fredrik_Steen]

8 hours ago, gtecomp said:

Hm...this MaxxECU can work with original trigger wheel...interesting 

Yes it works with stock wheel

if you press the big red help button in M-Tune and then scroll down to Trigger and open Suzuki Gsxr you will find my examples on trigger logs. 

Send a email to support@maxxecu.com

They usually reply the same day

[Arttu]

9 hours ago, Fredrik_Steen said:

I needed to change sensor on my maxxecu gsx-r 1100. We couldn't find Zero-crossing with stock sensor. Maxxecu support tried but with no luck.

 

 

Interesting. It's possible that this long tooth requires some special electronics to work properly with a VR sensor. Nice that they have some support for that stock wheel. Although it's another question if it's easier to change the sensor or change the wheel to something that works with stock sensor.

I'm going to try a MaxxECU on a Bandit with stock sensor and 24-2 wheel soon(ish). Interesting to see how that goes but I'm pretty confident it will work fine.

[Reinhoud]

No experience with EFI, but I noticed something.

You say it injects every second turn of the crank. Would it run better if it injects every turn of the crank?

 

[gtecomp]

MaxxECU state that:

Note: By default, any tooth that is longer than 50% of the previous, is considered a "missing tooth".

maybe this is how the long tooth is decoded 

 

[gtecomp]

2 hours ago, Reinhoud said:

No experience with EFI, but I noticed something.

You say it injects every second turn of the crank. Would it run better if it injects every turn of the crank?

 

Hello,

 

yes you are right. Once at 720 deg, that only one cylinder is on right spot to receive fuel

they have (MaxxECU)

No cam sensor, or 2 cylinders per injector output

Sequential 720 without SYNC - Same as Sequential 720, but ignores any cam sync. Can be used with engines without cam synced trigger systems. Since there's no cam sync sensor the injection angle can be 360 degrees off. This is determined each time the engine is started, and will always be the same when the engine is running.

Sequential 720 without SYNC may change the injection angle 360 degrees every startup, making the engine run a tiny bit different. For big injectors (>1500cc) this is usually preferable to 360 degrees injection to make it run better at low load.

 

I'm not sure what that means (obviously English is not my strongest skill), but how the engine determined right sync....first try 0 deg the 360 deg????

 

Sequential 360 will give a more even fuel distribution in non-camsynced systems or when using one injector output to drive 2 cylinders. But because of the shorter pulse width, the engine may run worse at low load/idle with big injectors.

 

[Fredrik_Steen]

On 12/21/2021 at 7:24 AM, Arttu said:

Interesting. It's possible that this long tooth requires some special electronics to work properly with a VR sensor. Nice that they have some support for that stock wheel. Although it's another question if it's easier to change the sensor or change the wheel to something that works with stock sensor.

I'm going to try a MaxxECU on a Bandit with stock sensor and 24-2 wheel soon(ish). Interesting to see how that goes but I'm pretty confident it will work fine.

The change to a new sensor was relatively easy, I used the oem base plate and added a tab to mount the sensor 

 

Love your new dyno, it looks awesome!

Would be fun if you documented your Maxx instalation on the bandit here on this page 

[Arttu]

2 hours ago, Fredrik_Steen said:

The change to a new sensor was relatively easy, I used the oem base plate and added a tab to mount the sensor 

 

Love your new dyno, it looks awesome!

Would be fun if you documented your Maxx instalation on the bandit here on this page 

Yes, not a huge project to change the sensor. On the other hand changing the wheel isn't difficult either. Undo the bolt, remove the wheel, insert new wheel, tighten the bolt. That easy!

Thanks! There is still plenty of smaller stuff to do for the dyno but it's indeed pretty useful already.

Let's see if I have time to document the Bandit installation. It's my friend's bike and I'm doing just the EFI stuff for it but might be worth of a "mini project thread".

[clivegto]

56 minutes ago, Arttu said:

Yes, not a huge project to change the sensor. On the other hand changing the wheel isn't difficult either. Undo the bolt, remove the wheel, insert new wheel, tighten the bolt. That easy!

Thanks! There is still plenty of smaller stuff to do for the dyno but it's indeed pretty useful already.

Let's see if I have time to document the Bandit installation. It's my friend's bike and I'm doing just the EFI stuff for it but might be worth of a "mini project thread".

Pleas do document it 

[gtecomp]

I share the idea of OEM 4 tooth sensor with my tuner ...and he doesn't  like it. He states that in forced induction  - more accurate ignition timing is needed as far as 5 deg more or less means destruction of engine . Maybe he is right.

 

 

Edited December 22, 2021 by gtecomp

[GSX1100dreamn]

I feel like I am reading the Penthouse forum pages reading the EFI banter....

 

Errr whatever Penthouse forum is, so my friend told me.

 

keep it up...hehe.

[Gixer1460]

12 hours ago, gtecomp said:

I share the idea of OEM 4 tooth sensor with my tuner ...and he doesn't  like it. He states that in forced induction  - more accurate ignition timing is needed as far as 5 deg more or less means destruction of engine . Maybe he is right.

True but depends on the ECU - I used one with slimmed down big tooth and MoTec and worked fine. The teeth are only points to count so the ECU knows when to trigger an event.

I didn't understand any of the maxx stuff above as you can't have sequential without a cam trigger. It's just random without unless someone explains otherwise!

[Arttu]

13 hours ago, gtecomp said:

I share the idea of OEM 4 tooth sensor with my tuner ...and he doesn't  like it. He states that in forced induction  - more accurate ignition timing is needed as far as 5 deg more or less means destruction of engine . Maybe he is right.

Yep, I would call that 4 tooth wheel as "risky option". It may work or it may cause some unexpected troubles.

If needed I can supply a 24-2 wheel that bolts on to oil cooled engines and works with the stock sensor.

[GSX1100dreamn]

Hi Arttu,

your 24-2 trigger wheels what is the static position of the -2 gap when No1 is at TDC.

 

Regards Andrew.

[Arttu]

First tooth after the gap meets the sensor at 100° BTDC.

[gtecomp]

11 hours ago, Gixer1460 said:

 

I didn't understand any of the maxx stuff above as you can't have sequential without a cam trigger. It's just random without unless someone explains otherwise!

Yep...I'll write an e-mail to them and asked for more detailed explanation....but here is my new bunch of questions: 

1. cam cover - is weldable? ... any magnesium strange alloy to be expected? I still consider the option to put hall sensor over some cam lobe.

2. dead time/voltage correction table of stock say what now!? 600 injectors. Before 7 years I put some weird values and I don't remember from where I get them.

3. some ignition table and VE table that work?   

Edited December 23, 2021 by gtecomp