Engine Start And Sputter

[rgoddard57]

I have a 99 silverado 4.8l LS ext. cab 2wd. It has a lot of miles on it and running strong up until now. Today I went to start it and its starts up and slowly drops RPMS below 500 then slowly stalls out completely. give it gas and it holds for a little then drops RPMS again and stalls. I put a small amount of seafoam in the intake helped a little and then went right back to the samething.

Anyone have any ideas on this cause im all out? No codes either!

[txab]

Check the fuel filter and check fuel pressure for starters.

[rgoddard57]

Thank you I will give the filter a try today. I haven't tested a fuel sytem for pressure before. anyone have any tips?

[nluchau]

Thank you I will give the filter a try today. I haven't tested a fuel sytem for pressure before. anyone have any tips?

On the passenger side of the engine ( on the 5.3's anyway) there on the fuel rail is a valve capped off. Remove the cap and screw on a meter. Turn the key on so your fuel pump starts but don't start it and you will be able to tell what the pressure is. you can also start it to see what the pressure is too. It may go down a bit which is normal because your fuel pressure regulator is taking over. Guys correct me it I'm wrong. This is what I remember when I had mine checked.

[rgoddard57]

I changed the Fuel and Air Filter and even ran some seafoam cleaner through it. cleaner helped but maybe only cause it burns fast. I will check the pressure. I really just want to sell this thing now cause I have a new car anyway. I do like the truck though.