Hard cold start

[Persizi]

About a week ago I started having problems with my GSX 1400. When it's cold it starts very hard, takes a lot of time on the starter and when it runs it's very jerky. If I turn off the ignition and start it again everything is just fine, the engine works very smoothly and the fast idle works. It happens even when the engine is warm. When I leave it for a half an hour or an hour, then it starts harder but If I turn the ignition off and start it again everything is fine.
I've checked the TPS and STPS sensors and they are fine. The fast idle is also fine. Any ideas?

[hard road]

time for a fuel pump clean maybe !!!!!

[Persizi]

I can try, but I don't think this is it. If it was а fuel pump issue it would do it all the time, no just on the first start.

[hard road]

I can try, but I don't think this is it. If it was а fuel pump issue it would do it all the time, no just on the first start.

worth a try.

[Blubber]

Check the basis, from up here sounds lik a  bad earth.

2x Battery connections
2x Big connectors on the starter relais
1x negative ground connector towards loom
1x negative ground toward engine

But also check the starter motor bolts
Mine were loose causing bad cold starts.

HTH

[Persizi]

All of those are fine. The starter cranks fast and well as usual. Even I charged the battery just in case. The engine not just starts hard, when it does it works very jerky on lower rpm, like the mixture is very rich or very poore.

[hard road]

try putting it in dealer mode and see if a code comes up.

[KiwiCol]

  it is a bit of a head scratcher isn't it      sounds electrical to me, perhaps the wires to the injectors (or 1 of them) are loose / dirty.      Unplug them, clean with contact cleaner & check for a proper fit when re-fitting & see if that helps.  Good luck

[Speedy1959]

A random thought..
Try flicking the kill switch a few times before you try to start it..
Just in case firty contacts..
My other thought would be check the clutch switch (Clutch lever) for dirt/bad connection.

[Persizi]

I fixed the problem. The fuel pressure regulator had pulled out.
Now I have another problem. One of the o-rings is worn out and I can't find another one. Someone to know where I find some of those?

[Speedy1959]

You will need to measure your O ring pretty accurately and then try these people..
They are superb and offer top quality items..

https://tinyurl.com/yckwy8tk

S

[Persizi]

Is anyone one knows the model number or the size? Because I already put everything together.

[hard road]

Is anyone one knows the model number or the size? Because I already put everything together.

probable not    Suzuki uses odd sizes with their O rings so it must be exact.

[Speedy1959]

You will need to measure your O ring pretty accurately and then try these people..
They are superb and offer top quality items..

https://tinyurl.com/yckwy8tk

S

Go on this website and look..
I would measure yours (or the Brass fitting) accurately and then buy several O rings going up in thickness..
You need to look at this website, or spend £257 on a new fuel pressure regulator!!

[Persizi]

This is not the pressure regulator o-ring. But the size looks the same.
I think I found it, OEM Part # 15113-35F00-000