I scanned the icp and the duty cycle and it will only make around 1900 at 92%. It will also only rev to 2500 and it takes a few seconds to get that high.

 

mine lunged. It would fuel up the motor and raise the RPM 400-600. But I think mine was an out of the normal symptom

 

Mine completely died with bad ipr. Your problem sounds like the stc fitting to me

 

Thats what mine did..

 

This one idles ok but it has no throttle response and will not pull itself up a hill

 

Where is the stc fitting

 

On the hpop

 

P.M. sent OP

 

2003's almost never have an issue w/ the HPOP discharge connection. Also, I have never heard Ford refer to it as an STC fitting for the 2003 and 2004 year models.

 

Its a solid piece on 03-04 isnt it????

 

No - it has a type of quick connect fitting, but it is strong enough that you just don't get the failure rate of the 2005 and up.

 

Thanks for the help so far. I've been given several things to check. When I get them checked I will post what I find.

 

Does it have the EGR deleted? My parents 04 6.0l would idle fine but when ever you would touch the gas pedal it would not move. The EGR valve was all full of carbon and sticking open. When you first start the truck the EGR valve open and close as part of the system start up.

Take the 10min and check the EGR valve.

Mike

 

At 92% IPR you should see more like 3500-4000 PSI. Sounds like a problem with a leaking IPR or a leak in the high pressure system.Your IPR may be commanding 92% but may be leaking 50% of that. Test,verify,repair.