99 yukon wont start. Have pressure at service port. Only have fuel pressure on one line. Truck runs if gas dumped in throttle body
Country: United StatesMake: GMModel: yukonYear: 1999Engine: 5.7
Welcome,What is the exact fuel pressure reading please?
dont have a gauge but sprays pretty good when relieved.
Thank you,That can be VERY deceiving though. This fuel system requires at least 60 psi to run and if you think about that, it's twice as much pressure as a tire has in it so when you depress the fuel test port valve it can shoot a heavy stream of pressure at say, 30-40 psi and seem like its enough but it HAS to be at least 60 psi t run. Thats why it runs when you pour gas into the throttle body. Click here for the testing procedure but i can almost guarantee you it will need a new fuel pump and please be sure to buy one from the dealer otherwise in a year you will have to replace it again if you get one from an aftermarket source.If you have further questions feel free to reply.Larry
35 years Master Mechanic