Kangaroo jumps

[johnroyle]

Can anyone help with ideas.

 

When pulling away, especially in 2nd from 1500 - 2000 rpm and when the engine is fully warmed up, the car lurches just as it did when you were learning to drive and had no clutch control.

 

All that has happened of late that I can think of is re- conditioned fuel metering unit fitted and a Remington TR pressure relief valve.

 

Could either of these have anything to do with it, or are there other suggestions.

 

John

[barkerwilliams]

John,

 

My car used to do this. My car is a PI, cause was butterflies not synchronised. Don’t think you can get same problem if you have Carbs.

My car was basically ticking over on two cylinders, the other four butterflies closed off but still getting the shot of petrol each stroke. When you opened the throttle and released the clutch to pull away the engine staggered and hiccupped until the revs increased. Once balanced the car pulled away smoothly.

First tell-tale sign on a PI, screw in the large tick over air screw, the engine should stall, if not air is getting into some cylinders either butterfly adjustment, or air leak on inlet manifold.

Second test is remove the air inlet plenum from the throttle bodies and blank off each throttle body / cylinder in turn. A closed butterfly will produce a small suction against the blanking cloth/hand/sheet whatever and no real change to engine revs. All six should be similar. If butterflies need adjustment two or more cylinders will slam the blanking device against the throttle body and the engine will stall.

If you have carbs or a pi then also possible that clutch shaft / pin has sheered but that usually seems to result in clutch drag as there is less movement to release the pressure plate but will also give a lumpy take off.

Which part of the world are you in?

Alan

[johnroyle]

Thank you - sounds a possible. West Yorkshire