engine stalling and low fuel pressure
It all started out with a misfire. No engine codes coming up ever. I looked under the hood and noticed a missing rubber EGR pressure sensor tube. I took it in and the Ford dealership said that the driver side cat was plugged and the EGR pressure sensor was shorted. ?? So, I had them replace the sensor and missing tube. They also told me it overboosted, which it did. I took it home and it was still misfiring so I replaced the mid pipes and cats with Bassani SS.
The truck ran fine for one run down the highway. Once I arrived at my destination, the truck started stalling. I limped it into the parking lot then had it towed home.
After troubleshooting I found that the fuel pressure was low when idling erratically, around 20-30 PSI and fluctuating all over. One thing that worked temporarily was using starting fluid into the throttle body to keep it at idle for a very short time.
So, now the truck starts, idles erratically, then stalls. The idle RPM goes up to 2000, then near 0, then back up a couple times before stalling. I can hold the throttle up and it will do it for a longer time, but eventually stalls.
I started replacing things. Changed fuel filter first, it needed it. Replaced fuel pressure regulator. Replaced fuel pump assembly.
I've checked many things and had many mechanics look at it, but everyone is befuddled. Most of the replacements were from suggestions.
What could it be?
cool air intake
single blade throttle body
higher amp alternator
accel coils and granatelli coil boots
NGK IX iridium plugs
Bassani mid pipes and high flow cats
everything else replaced is OEM