Hesitation on Acceleration -- but only sometimes

My girlfriend has the same problem on her car, every once in a while it just stumbles and falls flat on its face and then if you push harder on the gas it comes through the bog and goes like a raped ape. So far this goddam problem has led to me changing o2, map, knock, plug wires, cap & rotor, egr delete, and i put a completely different throttle bottle with tps, iac on it and still this problem comes back every once in a while. Weather seems to have no affect on it and it happens totally at random sometimes with the motor hot and sometimes when its cold. I would love to know what it is cause im getting fustrated. I have also changed the fuel filter and checked pressures. I know a couple other guys with this problem and would love to know what it is.

garry said:

My girlfriend has the same problem on her car, every once in a while it just stumbles and falls flat on its face and then if you push harder on the gas it comes through the bog and goes like a raped ape. So far this goddam problem has led to me changing o2, map, knock, plug wires, cap & rotor, egr delete, and i put a completely different throttle bottle with tps, iac on it and still this problem comes back every once in a while. Weather seems to have no affect on it and it happens totally at random sometimes with the motor hot and sometimes when its cold. I would love to know what it is cause im getting fustrated. I have also changed the fuel filter and checked pressures. I know a couple other guys with this problem and would love to know what it is.

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Count me in also

Mine is the same thing at random and acts like vapor lock sometimes to me. My car usually does it when I'm about to enter on to a main road and I got just enough time to beat the on comming tracfic, then it bogs like crazy

So fair I've changed the plugs, only other stuff is like a CSI and full exhaust because the old exhaust was falling off ( deleted pre cat). What I plan to do was change the: TPS, EGR, Fuel filter, and PVC, but seening how you have done most of that if not all and no improvements makes me wonder if it would even help me out. Also I get a code for the TPS like once a month and the light never stays on that long and its off again for the next month. The idle at start is usualy high but settles down once its warmed up though. what to do ummmmmmmmmmmmm

Have you changed your spark plug? or just checked them? it could be a electrode that is broken.. or somehing like that..

I had a problem like that, only not that extreme with a non-ford, turned out to be fuel filter.