Mk 2 jag judders sounds like misfire but no bang noise

[Davidgilpen]

Hi I put my jaguar mk2 away few weeks ago no problems been out for long ride,when I started it on Saturday it seems to judder when I rev it ,I took her out but seems to judder when pulling of lack of power can any one help as to why this should be ? It judders in neutral so it can't be transmission, could it be spark plugs or dissy or maybe coil? I am not good with mechanics so any help would be grateful do you think it could be only firing on 5 pistons ?

[jimbob82]

probably damp in the distributor cap. pull the cap off and see if there's any water in there. if there isn't, pull the plugs out 1 by 1 and see what they look like.

[Davidgilpen]

Thank you I will try the plugs it can't be damp as I never use car in wet and it hasn't seen rain in 24 years, I know the car is a bit rich or has been by the sounds of it then its going to be something simple like electrics thank you for your info much appreciated

[SV8Predator]

How long ago was 'a few weeks'?

If it was a few months, it may be 'old petrol' which behaves exactly as you have described.

If not, and the petrol is good, you're going to have to do some fault finding. Nobody on an internet forum can do that for you, other than providing, 'have you tried this?', 'it could be this', ad finitum.

[Davidgilpen]

Thanks for input it was only a few weeks ago I used it and put fresh petrol in, I have checked the oil in carbs and topped up and both valves in pot are moving up and down one thing I have noticed is the fuel pump keeps making tapping noise quite quick all the time when you turn on ignition usually it makes noise until pressure built up then stops but it just keeps on tapping away do you think the fuel pump could be the answer? Thanks Dave

Edited by Davidgilpen on Wednesday 19th June 21:07

[jagracer]

Pump running all the time sounds like the carbs are flooding, turn the ignition on but don't start the engine, follow the copper overflow pipes to where they exit underneath the car and see if any fuel is running out.

[jimbob82]

Davidgilpen said:

Thank you I will try the plugs it can't be damp as I never use car in wet and it hasn't seen rain in 24 years, I know the car is a bit rich or has been by the sounds of it then its going to be something simple like electrics thank you for your info much appreciated

your welcome. humidity can penetrate into the dizzy, even if you never take the car out in the wet the damp can still get into the cap, especially if it's old or maybe even has a crack?