Based on the information, I assume it is the fuel filter you changed, that you have good spark and have done a fuel pressure check. I doubt that ALL the injectors would be clogged. I would think the fuel pump is faulty.
Check to see if fuel injectors clogged/ or fuel injectors getting power (requires special noid testor) . I take it you checked fuel pressure at fuel rail.
Injectors are clogged
Are you getting power to the system?
Faulty fuel pump. Faulty fuel pump relay. Faulty fuel pressure regulator. Clogged fuel filter, pickup, or line. No fuel in the fuel tank.
Empty tank Clogged filter bad pump
it will spit and sputter or miss or just not have no power at all very sluggish
I also have a 94 350 that I built from scratch and have the same problem. Could be anything really. Out of time, TB rebuild, clogged injector. You may want to start with making sure it's getting good fuel pressure out of both injectors, if not you could either have the fuel pump going out or a clogged fuel filter. I also have a 94 350 that I built from scratch and have the same problem. Could be anything really. Out of time, TB rebuild, clogged injector. You may want to start with making sure it's getting good fuel pressure out of both injectors, if not you could either have the fuel pump going out or a clogged fuel filter.
Check your fuel pump and fuel injectors. Have a fuel pressure and flow test done.
It sounds as if the fuel filter is clogged and not getting enough fuel to the injectors.
The primary cause for jerking on a 99 Mercury Cougar is the engine not getting enough fuel. This can be a sign of a clogged fuel filter, bad fuel pump, or clogged fuel injectors.
Bad fuel pump, clogged or broken fuel lines, or if it is fuel injected it could be bad fuel injectors.
A clogged fuel filter, bad fuel pump or the fuel line is blocked/damaged. What about a fuel relay fuse?