I have a disco 93 petrol 3.5 It started running a bit rough then as i would hit about 80kms an hour a Vibration fit to make the wheels fall off will start!!! let my foot off the accelerator it calms down put it back and im sure you will have no teeth left by the end of the journey i have taken it to three mechanics to no avail it is only when the car is under load for instance if you start going up a hill we changed the air coolant sensor ( somebody told us that would help) it didnt,
Changed the fuel filter, i also added nulon fuel system cleaner all started to go peachy then on next tank off fuel back to the shaking PLEASE HELP ME!!! also can you guys try not to be to technical as i am a girl and i have to relay all off this to my dad so he can repair it LOL!!!

 

whats the mileage on your truck? have you rebuilt the front drive shaft with greasable u joints yet?

 

yes that has been done it has done approx 160,000 kms

 

It is your VSS (vehicle speed sensor)
It is acting up and needs to be replaced.
It is the speed limiter for the truck, if it thinks you are driving to fast it kills the spark to the engine one cylinder at a time to slow you down.
When it goes bad it acts up while under load, so when trying to drive up a hill or take off from a stop.

 

DI's come from the factory with all grease able u-joints, only DII's do not.

 

misread his post. didnt even see 93... thats what i get for speed readin posts @ work.

 

LOL!!
I am the same way, anything longer than a paragraph and I am lost and forgot what the post was even about.
And if the spelling, English or punctuation is really bad or it is a run on sentence then I just spin the wheel of answers and post whatever it lands on.