aaron_strong

Fuel pressure is good maf is clean and 250000 on her

nba1341

Do you have a vaccum leak or a ****ty cai. I had a backfire with the am 60 dollar cai

rbowmar

Wow! you have stumped everybody! Ford, Your Mechanic and (temporarily) the assembled knowledge of the Mustang Forums.

Considering the miles on the car,I'd suggest a new coil pack and plug wires. I have had a couple of 3.8s quit completely after running horribly. A new coil pack and plug wires fixed them right up.

I am sure there are others with more expertise than I.

The one time I had the opportunity learn troubleshooting the rest of the system, My ECU failed with a clear error message, allowing me to bypass a lot of trouble shooting. I don't think this is your problem. When it finally went, it was just like some one reached past me and turned off the key.

Good luck!

StangsTN

I had a similar issue that ended up being a vacuum leak.

bmaytum

I'll take the vacuum leak over the dead ECU any day!

robb15033

If it's loosing pressure when the cars off, you replace the fuel pump. The check valve is built in.