after installing my headers, the car had almost like a miss or rough idle,and when it gets warm it doesn't want to start up. cranks over and has fuel pressure and spark. well when checking the fuel pressure we noticed my fuel coming out of the pressure release on the gauge was bubbling(boiling). is this vapor lock and if so would it be the cause of my rough idle and hard start? could the egr valve cause the rough idle?
thanks for any help
roger

 

sorry ,it's an 89 transam 350 tuned port

 

I'm not saying that it isn't Vapor Locked, but I find it hard to believe that it would be. Pressure raises the boiling point of a liquid. Hence most cooling systems are 15psi systems. That raises the boiling point from the normal 212° to like 260°, and thats only 15psi of pressure. Although gas has a lower boiling point, your fuel system should be about 40psi, so it may be boiling when it hit atmospheric pressure, but while in the fuel rail, it should not be. Carburated engines were really prone to that due to the low pressure (3-4 psi) of the sytem.

 

i agree, check to see how close the headers and exhuast are to the fuel lines. unless they're extremly close, there shouldn't be a problem.

by the way, what part of ohio are you from? i'll be in the cleveland area the first week of sept