Vehicle Juddering whilst driving

[Bertievan69]

I was taking my van for an MOT this morning. It started without any problems and sat at idle comfortably however when I set off to drive to the garage it was very juddery so opted to return home. I have recently cleaned the spark plugs but wondered what opinions where as to what could be the problem?

 

[subheatadey]

Did you push the HT caps firmly back on the plugs?

 

[Bertievan69]

Did you push the HT caps firmly back on the plugs?

I believe so but will check when I get home. Had no issue starting just whilst driving.

 

[ozziedog]

I’m with Ade on this one. It is nearly always the last thing that you touched and these are a bit of an art getting into them and my cranky old fingers aren’t as nimble as they was once making it a bit more of a mission. Check both ends and listen and feel for the clicks.
If you want to check, you can pop them out at the dissy end to see if it changes it’s tune,then you might know where to look at which lead.

Ozziedog,,,,,,,,,,, get that mot sorted.

 

[Mechanoid]

If the above doesn't sort it, drain the petrol from the carb float bowl. It may have water in the bottom of it and gets picked up when you try to accelerate. If you are using E10 fuel, this is becoming a problem as the Ethanol absorbs water and it deposits on the lowest part of the petrol tank, right where the fuel pick-up is!

 

[naskeet]

Many years ago, I experienced violent juddering owing to a faulty governor-type rotor-arm, which shorted-out the HT ignition pulses to the spark-plugs at engine-speeds substantially below the 4,500 rpm threshold (corresponding to circa 30 mph in 4th gear!), which on our 1973 VW 1600 Type 2, AD-series engine, would normally not occur at circa 50 mph in 3rd gear and never rev fast enough in 4th gear, because circa 68 mph in 4th gear, was the vehicle's maximum speed. Substituting the new governor-type rotor-arm from our touring-spares kit solved the problem.