ionic Gulpfile (or dependent module) not found - ionic-framework

Question

I'm trying to open a project that i downloaded from github.the project uses ionic 2 but it returns this error :
[ERROR] Gulpfile (or dependent module) not found: .\gulpfile.js
For custom Gulpfile locations, you can run ionic config set gulp.file
<path>. Otherwise, the default Ionic Gulpfile can be downloaded from
https://github.com/ionic-team/ionic-app-base/blob/master/gulpfile.js
Or, if you don't use gulp, you can disable it by running ionic config
set gulp.enabled false.
Full error:
Error: Cannot find module 'ionic-gulp-sass-build'
at Function.Module._resolveFilename (module.js:538:15)
at Function.Module._load (module.js:468:25)
at Module.require (module.js:587:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (F:\ionic3\exemple
taxi\Ionic-2-Uber-master\gulpfile.js:31:17)
at Module._compile (module.js:643:30)
at Object.Module._extensions..js (module.js:654:10)
at Module.load (module.js:556:32)
at tryModuleLoad (module.js:499:12)
at Function.Module._load (module.js:491:3)
i tried some solutions like :
1-Delete your node_modules folder
2-Remove gulp-sass from your package.json file
3-Remove node-sass from your package.json file (if you have it in there)
4-Run npm install gulp-sass --save-dev
Also this one :
1-update version-clean
2-the node_module and executenpm install
3-may be npm cache
But i still have the same error .Is it that i installed ionic3 and the project runs in ionic 2 the cause of the problem ?