I have a 1994 f150 I-6 5spd 4X2. It has a hesitaion and rough Idle. The problem is that when i go to take off i have to push the gas 1/4 inch before the motor will start to rev up, there is stil a delay of a couple seconds before anything happens. The other problem is a rough idle/slight miss after more than 45 seconds idleing warm. over the past year i have replaced the distributer cap, rotor, plugs, wires, O2 sensor(this caused somewhat of an improvment), temp sensor (after back flushing and refilling the cooling system and replacing hoses). I have also used fuel injector cleaner and put seafoam through the throttle body. now i am looking at doing a few more things for this they are

1. pull IAC off and clean it

2. replace TPS

3. get one of those tools(i forget what theyre called) that detects how much voltage a sensor is putting out so i can see if it is bad.

4. clean MAP if it can be cleaned

Does anyone else have this rough idle/ hesitation? if so, will doing the 4 things that i listed above fix it?

thanks

 

Sounds like your TPS, Get a Digital Multimeter perferable one that is AUTO RANGING, $30-40 should get you something that will work pretty good, if you want something that's made well and very acurate, shell out around ~$80 and get a low end FLUKE http://us.fluke.com/usen/products/Fluke+12.htm?catalog_name=FlukeUnitedStates.
The Throttle Position (TP) sensor is a potentiometer that provides a signal to the PCM that is directly proportional to the throttle plate position. The TP sensor is mounted on the side of the throttle body and is connected to the throttle plate shaft.

The TP senses the throttle movement and position and transmits an appropriate electrical signal to the PCM. These signals are used by the PCM to adjust the air/fuel mixture, spark timing and EGR operation according to engine load at idle, part throttle, or full throttle. The TP sensor has 2 versions, an adjustable and a non-adjustable; the difference being elongated mounting holes that allow the rotary sensor to be turned slightly to adjust the output voltage. The rotary TP sensor with round mounting holes are not adjustable.



Check Ohms with unit unplugged from harness;3K Closed to ~20K OPEN Smooth increase no Jumps No OL (Open Lead) (Check resistance across the 2 dark colored wires)

Check Volts With Ign ON and unit plugged in
VREF = 5VDC (Yello strip wire)
Sig Return to Grnd
CLOSED= ~.5 VDC
OPENING 1 to 5 VDC FULL OPEN

If any reading is out of spec replace the sensor $30-50
Hope this helps
Good Luck