Modern Vespa

I have an injection gts125 ,it starts fine and ticks over lovely but soon as I rev it dies. Has anyone had similar problem. I do have a code scanner on a slow boat from China. Which I hope will give me a clue. I was hoping it would be as simple as a side stand switch but this model doesn't have one.

when you turn the key on what does the flash code led in the dash do?

how many miles?

The bike had a replacement engine and it's done about 19k.
Previously it was flashing but when I started it today there wasn't any flashing . On the eiss light. Only abs light on , which I guess will go out when I can ride it down the road

The bike had a replacement engine and it's done about 19k.
Previously it was flashing but when I started it today there wasn't any flashing . On the eiss light. Only abs light on , which I guess will go out when I can ride it down the road

without much to go on, and no service history...

have you checked the: all of the evap lines, intake manifold, air filter, spark plug, spark plug cap, HT lead, injector. have you cleaned the air bypass in the throttle body? check the valve clearances?

from there I would suspect a fault in the immobilizer system. probably the antenna or chip/key where something has either lost code or is having an intermittent connection.

Would it start and tick over if the chip didn't recognise the key ?

yes. it is possible for the bike to start, but it is kept under an RPM threshold, when revved the spark is cut out by the computer. usually it will just sound like it's running really really poorly, but sometimes will will just cut out. it will restart immediately and exhibit the same behavior.

my follow up answer to your follow up question (which is: how do I fix the ignition/key/ECU?), would be to ensure that you have eliminated any and all other possible causes or underlying problems before deciding that the ignition system is the part that needs fixed; and yes, the ecu and keys are expensive.

Thanks for that, I'm a bit of want to fix rather than replace. Where could I read up about in depth setting of the code etc in the ECU. Or is I kept on Piaggio s best kept secret vault.
I have the original blue and brown keys. And a code card.
My thiare going to the antenna, wherever that is.

Turn it on and then off. The LED should now be flashing slowly and continually.

Turn it on again, the LED should flash and finally go OFF. If it stays flashing, there's a problem with the ignition switch (not uncommon). If it remains ON, then there's a problem with the immobiliser system recognising the keys. The number of flashes (and their duration) before it remains ON can indicate where the problem lies.

Read the service manual which explains all the different codes.

https://manuals.wotmeworry.org.uk/Vespa/GTS125/ Use the GTS125ie Super one - this not the ABS version, but that's not relevant here.

Thanks for the info I will have a look this weekend. I will post how I have for on.

Well ongoing vespa project. I have reprogrammed the keys..
Found injector semi broken so replaced.
Then found I needed to calibrate asr. Thank you for video Portland vespa.
So bike has very low power I managed to ride it for a mile and got it to 50 downhill having to let the throttle off . It doesn't smoke.and starts first time and ticks over fine.
So any more clues on what to do next to get some power out of this little 125 would be welcome.