Mild throbbing idle and throbbing revving
 

Hi my Eddie Bauer 1999 shoc 4 l is having this smooth but throbbing idle and revving. All was good two days ago. I accidentally put the auto box in 2 (most likely) or 1 instead of drive and at the same time the overdrive button was also pressed. FYI I was not on the phone. Anyway I was racing, which I should not do with another car and I floored it. It climbed the rev and flattered out without changing to a higher gear. Anyway I kept it floored since it always changes up.. It didn't for maybe a second by that time my turn came and was off the pedal. While I floored it and after reaching high revs it felt like the fuel was cut off, and it reached a plateau.
After the turn I looked at the dash and saw the overdrive light on , and the gear selector in 2 instead of D, drive. I put it right, the next day it seemed fine, in normal driving, but yerterday when I started in the morning the above situation developed. Also when I go 60 kph which it the speed limit in town, it vibrates like it is on gravel.
Any ideas please?

Any CEL?

UPDATE: The mechanic said it was 2 or 3 broken spark plugs and 2 HT wires bad. It is running like before the overrevving, with a slight miss at ideal. Don't know if the overrevving caused it - but glad its fixed.

Overrevving
 

My 2003 Windstar is trying to kill me and my family lol. I’m the only one authorized to drive it(not really) but I must keep on the brake at stop lights or I could plow into someone in front of me. The best description of what’s happening; when in gear—it starts almost immediately overrevving. In park not really. As I step on the gas (even just lightly touch it) overrevving starts if putting it into drive doesn’t cause it. It’ll drive at speed fine and in fact I don’t even need to press the accelerator for it to increase in speed. From a slight touch of the pedal we’re off and running. Stopping is a chore. The poor brakes will be toast by the end of the week—trying to stop the car that’s still revving to the moon. I’ve rolled into a stop in neutral when the moment it’s shifted into neutral the rpm’s through the stratosphere. Many times as the car comes to a complete stop, the revs come down as abruptly as to almost stall the engine. Other times if I keep it in gear come up to the stop light the same thing may occur(as I grind to a complete stop the revs just die). Help me to understand.

Overrevving again and this time I’m implicating the cabin fuse box’s number 17(20amp). I noticed this needed replaced the last time this problem occurred (only a few weeks ago) and my OBD DataPoint wasn’t working. Today again Autozone’s scanner confirmed there’s no comm link with the PCM. I’ll change that fuse tomorrow to see if that cures the overrevving issue. I’m sure I’ll get commlinks back with the OBD datapoint . And the MIL will extinguish as well I’m hoping—I’m just curious to know what keeps blowing this particular fuse. In fact since replacing it, I’d instructed everyone not to plug into the cigarette lighter for charging of phones. Any advice would help.

https://cimg3.ibsrv.net/gimg/www.for...3ebcd7e867.jpg
https://cimg4.ibsrv.net/gimg/www.for...d6c305a84b.jpg
https://cimg5.ibsrv.net/gimg/www.for...1da1d680e0.jpg
https://cimg6.ibsrv.net/gimg/www.for...4f00b27da8.jpg
Fix the short to ground issue first, then download the pedal.zip attachment.

Overrevving again
 

Yes sorry HEIKO it’s a 2003 Ford Windstar Base model 3.8L V6

My alldata software pulled up only V6-3.8L on 2003 if you take a look at bottom of the diagrams that I posted you can see I got that right.
The misbehaved pedal is very important and require immediate attention, you should not drive it further until it's really fixed, but then the short to ground on your cigar lighter circuit is easy to fix so I suggest you to go over that first, it's pretty simple circuit you start from C270D.

Over-revving Windstar
 

First off—GOD BLESS you my friend. When a new car isn’t yet an option we make do with what we have. I’ve personally swapped so many parts on this car I’m on autopilot through most repairs. I’ve got homemade tools just for this vehicle’s maintenance. I swapped engines, transaxles, suspension and steering parts; I’ve even removed and repaired the entire engine cradle where it had been bent(which included cutting, welding, grinding and painting). I’m about to flush my steering system before a long 8hr drive from NY to NC. The one thing I’m not at all proficient in is reading and implementing electrical diagrams. Are those circuits germane to my application surrounded by the dotted line? Is that the junction box in the engine compartment or under the dashboard. Just so it’s understood, this vehicle had no luxury features(base model)

Here's an EXAMPLE of power and ground distribution:
So C270a here is equivalent to your C270d, the so-called current flow starting point in the diagram.

https://cimg9.ibsrv.net/gimg/www.for...9b03d46ed7.jpg
The CJB location below:
https://cimg3.ibsrv.net/gimg/www.for...389ea3ca5f.jpg
I doubt your datalink circuit is at fault and I think your cigar lighter probably since it's most used, you plug and unplug daily, and by design on all cigar lighter sockets the + and - are very close to each other and it's easier to get your short there than the middle of the circuit.