Hi,
I have searched the forums and found similar hesitation probs, but maybe not quite the same, and most suggestions start with changing the plugs/wires which have been replaced (with Ford performance wires and Autolite DPs) with no effect, fuel filter is also replaced regularly.
The Problem: When hitting the accelerator from a stop, or if driving down the road at low rpms (i have a manual), if i hit the accelerator more than lightly, the car shudders and stumbles until the rpms get up at least above 2500, then it smooths out. Even idling now, if i hit the accelerator there is a noticeable shuddering and slow increase in rpms until they get up in the 2K+ range. From a stop, if I accelerate carefully I can avoid the stumble, but if I need to move quickly, I am helpless. I can also avoid the problem by revving the engine up a bit before dropping the clutch. I don't normally drive fast and with gas prices try to take it even more easy, but this is a problem that will probably shorten the engine life if left as is. It happens in any gear and at any speed if the engine is not at higher rpms. Cruising at 30-35 mph in 4th, if i hit the accel, bucks n stumbles with no acceleration until the rpms go up. The secondaries appear to be working when required, giving a boost at 3500 rpm. The car idles perfectly for a car with 97K on the OD. I have added berryman's a couple of times, and spray cleaned out the intake, all of which always look shiney clean. I tried pulling one plug wire off at a time, and giving the engine a rev, and each wire removed made it noticeably worse, meaning it isn't just one spark plug or wire causing this. I replaced one of the O2 sensors last year due to a 420 code and CEL lighting (replaced the one that is hardest to get to under the coil area), the light hasn't come on since and isn't coming on or blinking even with pretty serious stuttering and bucking. I haven't made any other mods.
Anyone diagnose something like this? Next step for me would be to take it in and pay someone $100+ for a diagnosis, the going price for a diagnosis that requires actually raising the hood and not just plugging a computer in.
Thanks!
