weak start

[transgta]

My 00 yukon 5.3 sometimes when starting it acts like its gonna die just barely starting after a few secs its fine. Nothins really out yet but i dont wanna break down it seems like not strong fire any ideas to check DAVE

[Scrapper]

could be cable needing where cable go's or your tbs. is your check engine light on? may want to sick sea foam in gas or other people think of lukas. well i will stick with my sea foam use it in rv/my bike and my cars and truck.

[j cAT]

Originally Posted by transgta

My 00 yukon 5.3 sometimes when starting it acts like its gonna die just barely starting after a few secs its fine. Nothins really out yet but i dont wanna break down it seems like not strong fire any ideas to check DAVE

fuel pressure testing,,,need 60psi approx for a good start up..check the forums for the correct detailed test proceedure..

could be the ECT out of range..

[HUNTERPAUL]

This 5.3 engine has some issues with the intake gasket leaking vacuum and can cause rough idle and low idle. A new gasket is available to repair this problem. A can of carburator cleaner sprayed around the gasket while the vehicle is running can show if it is leaking or not. "when fluid hits vacuum leak you will notice a change in the engine RPM" Also the throdle body assembly usually needs to be cleaned up to solve some drivability problems.