Peugeot 505 Sri A Injection Drowns

I have a Peugeot 505 Sri to electronic injection that drowns when the car is moving. The strange thing that when the car is still I have no problem. I hope you can help me
Hector 63

You have some cracked gasol mango and throws air and stops. When it does not go, I don't stop why it is not revolutionized trying to walk it without walking. A greeting

Robertv

thanks for your answer, but still fails. I explain this Peugeot model came out with a Renault 2.2 injection engine (gasoline or gasoline), and has a caudalimetro. The engine starts normal in gasoline and does not drown (idle) when I accelerated it. What catches my attention that in Gas (CNG) is the most. From now on waiting for your answer.
Hector 63