my truck was surging at idle.cold and warm.Now just starts and dies.ive replaced intake gasket and plenum gasket.Idle air control valve,throttle position sensor,map sensor,coil,ignition control module,cap and rotor,spark plugs,Ecm,still no change PLEASE HELP.

 

Welcome to the site

Checked the fuel pressure/volume?
Will it accelerate/throttle snap to higher RPM. Or is it that it just dies at idle?

 

yes it will rev and drive the road the idle is the only issue at this time.i also replaced coolant temp sensor.I havent checked fuel pressure since i first started working on it.It was right around 40psi with key on.The exhaust also smells like its running very rich.

 

Did you check to see if it’s ingesting raw fuel through the fuel pressure regulator vacuum hose? If the diaphragm ruptured, raw fuel will be drawn into the intake.

 

Vacum hose is completely dry replaced regulator twice

 

Did you get a chance to check the EGR valve?

 

That was one of the things crossing my mind. If the EGR is hung, or the EVR failed/open, the EGR would choke it out at base RPM's...

 

Actually just changed the egr valve yesterday.with no change ran a can of seafoam through the intake.the hesitation is gone but idle still the same.

 

Do you have anything that would pull codes from the ECM?

 

No i dont have anything to pull codes.im not getting a engine light either which seems weird.