problem at idle and low rpn on my GS1100

[JohnGS1100]

My name is John, i m 43 years old and i am from greece.
Hello all friends in forum.

My problem :

After service on my bike i ride fine 2-3 days. One morning, i try to get on, and the idle is not than before, and when i m running at low rpn the motor sames like cough flu.

I check :
fuel presure regulator.
Oil and fuel filter.
Sparks.
Battery is ok.
Valve is ok, 15 in -30 ex.
TPS is 3,6 v (ok).
thorcle is clean, injectors clean.

I read many thead in forum but i dont find solution.
Any help ?

(Sorry for my poor english).

Thanks

 

[MattW]

Have you checked that the throttle cables are properly seated?

<a href="https://picasaweb.google.com/lh/photo/00QCs-gD2whktJApx3Eiwxsr8bdTfpHOPvwb62D6I-c?feat=embedwebsite"><img src="https://lh3.googleusercontent.com/-ntRKM4qLpjI/UExYvBWmMwI/AAAAAAAAFRw/3gTCXfXti_Q/s800/photo.JPG" height="312" width="191" /></a>

 

[JohnGS1100]

Thanks i check it and it is ok.

Any idea for electrical problem, relay etc ?
At high rpn i have good function but a little low performance.

 

[JohnGS1100]

I just resolved !!

The problem was the fuel filter. I replace it and it is all rigth.

 

[MattW]

I just resolved !!

The problem was the fuel filter. I replace it and it is all rigth.

Excellent

 

[Vern]

You said you checked the fuel and oil filter, so was it just blocked or something else wrong with it?

Welcome to the site by the way

 

[JohnGS1100]

You said you checked the fuel and oil filter, so was it just blocked or something else wrong with it?

Welcome to the site by the way

Yes. The first time i was clean the fuell filter. But after few days i replace it by another after market for second check and now is ok.
I think that need another fuel pressure regulator not 3 bar but 3,5 or 4 but for better iddle. What you say ?

I make and tunning program on ecu (i m computer enginier).

I correct the maps :

Fuell injection Before :

The new map :

Advance map (old) :

And the new one :

After these maps the bike working better runs 200-210 km/h.

 

[justabof]

Well, I'm impressed! Welcome and well done!

 

[JohnGS1100]

Thanks

I can do the same correct on maps to gs850, and gs1150 too. It is easy by program a new one chip (just replace on ecu).

It is work with free air filter K/N and the motor go up 5-10 Hp and 5-8 Nm.

 

[Rastaossie]

Hi
your program looks interesting. Can you tell us about it? How do you read the maps? do you have interface to the ECU or do you read the chip(Eprom?) directly? etc etc. Anyway stay upright.

 

[Vern]

Top man, what has it done to the fuel consumption!

 

[JohnGS1100]

It is must for good performance. Bmw haw low fuel (for concuption) and very low advance, i think because the gas for many country it is not so good. But if gas has 95 econ or higher then the more advance can go on the motor givea up to 85 Hp at 7100 rpn and up to 90 at 7.500+. The Torque is higher at all rpn up to 5 Nm.

I read the chip and i find the maps that's it all. The chip is 256 kb Eprom and the software to write on it, is 64 kb. If somebody can read by eprom reader the chip, let is go to send me via email and i send back the new software with new maps) to write (itself) on a new chip (27C256).
I can do this for 850 GS, 1100GS and 1150 GS and RT (has the same bosch monotronic ECU).
Thanks for look.

 

[JohnGS1100]

Today i replace the fuel filter by one after market for low cost :

 

[JohnGS1100]

Here is the change of fuel presure regulator by a new one from bmw 316 E36 1993 :

The left is the original.

Thanks for looking.

 

[MattW]

Today i replace the fuel filter by one after market for low cost :

This is not a high pressure fuel injection filter - you may find it will burst.

 

[JohnGS1100]

I think that working well. I 'll check it, thanks

 

[JohnGS1100]

I m thinking to put pistons from R1100S. After this the compres ratio go up to 11,3:1. What says my friend?
The diameter of valve from my 1994 year model GS1100 is longer that nest model from 1996 and early. I think that the power go up to 95 Hp. at 7.200 rpn.
If put and camshaft from 1100s then the power go up to 100 Hp. at 7.600 rpn.
What think about my idea ?

piston R1100s

piston 1100gs

camshaft for power