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RE: 1994 Mustang 3.8L V6 Auto.

Issue: Rough Idle or Miss at idle, stumbles when you first give it gas - Barely noticeable at idle but once put in drive with foot on brake you notice it easily, and gets worse with A/C on.

Past: Car has been on the road running like this for 2-3 months now…. But sat for over a year previous to me buying it and fixing (Fuel Interia switch was Red Neck wired wrong to fuel pump) – at the time I dropped the tank and did not appear to have any ethanol damage in tank (seen it many times), ended up removing red neck wiring and just temporarily bypassed the fuel inertia switch with a wire and spade lugs crimped on.

Work Done: Changed Passenger PreCat O2 Sensor (had code – no longer does, Clean MAF with MAF Cleaner, Clean Throttle Body with TB Cleaner, New Spark Plugs, Fuel Filter, Lucas Fuel Injector Cleaner added twice in last 3 months, checked and replaced dry rotted vacuum lines.

Concern: It was not clear in the post but someone seemed to imply a bypassed the fuel intertia switch caused problems with their Mustang – Mine is bypassed but can’t see how it would be a problem.

Only Code Showing: P1407 EGR No Flow. (Vacuum to EGR Valve kills motor)

From reading it says I should have 30-40lbs of fuel pressure:

I have 32lbs at Idle, if I drive it down the road or rev it drops to 25-28lbs.

Also when I shut it off…. The fuel pressure is solid at 30lb for a minute….. then started dropping until it got to about 20lbs within a few minutes.

If I disconnect the Vacuum line from the fuel regulator – IT DOES NOT CHANGE - Reading says it should go to 40lbs but it stays at 30-32lbs

The video clip below is showing my cheap Bluetooth OBDII Reader to my Android Tablet using “Torque” (have concern with the after cat on bank 2 O2 Sensor not dropping down after engine revved.

I am thinking I need to start with a Fuel Regulator, if that does not fix it drop the tank and inspect the fuel sock as well as check all lines to make sure none are crimped (motor was lifted recently to put new oil pan gasket on)

Any thoughts?
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