This just happened yesterday, nothing has been done to the engine before this for at least a month.

Truck tries to turn over but then just dies. Only way to get it running is to give it gas, I go about halfway, then it will start, I still have my foot on the gas and slowly release it till it idles. Then the truck runs fine.

Yesterday I replaced the MAS and the temperature sensor, was on my list of things to do and since it was free I went ahead and replaced it.

Few days ago I had the muffler replaced, the guy told me the muffler was turning blue because of unspent fuel, which is why the muffler went bad but said the cat was fine.

Any ideas?

 

First thing to check is fuel pressure and leakdown. https://blazerforum.com/forum/2nd-ge...eakdown-88305/ Post all 4 readings and we can analyze them for you.

 

Year, engine, 2wd or 4wd, auto or manual would be helpful information.