I have a 91 rs 3.1,owned car 3 months no problem at all.I added a bottle of fuel system cleaner to full tank of gas and 2 days later on a shot trip it started bogging/wanting to stall if i gave it any gas at all.I would let off gas and it would idle ok, press gas pedal want to stall.I limped it like that for 3-4 miles at 15-20mph then all the sudden all was ok and drive fine.
I connected FP guage to the shraded ..instant 41psi left it connected, ran the crap out of it for several days, no further problems.
I removed the FP guage...several days late same thing...acted up then cleared up.
I put FP guage on again...same reading rock solid...ran great for several weeks ,removed FP guage....just happened AGAIN ....
Do fuel pumps die a slow death ?
Please let me know what you guys think...what else maybe to look at...
thx for the help

ps istalled new fuel filter after first episode..

 

Deja Vu.

Can't gurantee we have the same problem BUT:
The EXACT same thing happened to me. I felt like my car was a little sluggish up to so i ran some Valvoline synpower through it. Next thing i know the car is doing exactly that. It runs great for a bit, then it would go crazy and try to die whenever i wasnt in the throttle. When i purged the rail it would clear up but then go haywire again soon after.

In my case it was actually the fuel pressure regulator. I replaced everything else that could cause the prob on mine before i did the regulator too.
So now i tell everyone who comes through here with fuel problems to check thier regulator.