4.0L Disco II auto misfire

My 99my Disco has what seems to be a misfire it drives fine untill it reaches 4th gear,it then develops a major misfire,when put on the computer it idles fine but on a run it has a severe misfire in 4th the computer shows its missing on all cylinders with no pattern.I have replaced the coil packs and HT leads(magnecor) i also replaced the plugs with the relevant champion ones.This seems to have improved it! The car also has a gas conversion(prins vsi) when running on gas the symptoms are not as bad, any thoughts or advice would be very helpfull. mny thx Tim.

Hi Tim,

this sounds similar to what i'm suffering at the moment (95my 3.9 disco). Gneral throughts are airflow meter with mine.

Check out the "stuttering disco" thread.

Si

Hooray :) spoke to Rpi on the phone ,ran through the symptoms they advised me that it all suggests air flow meter,so i bit the bullet bought one and yippee the V8 goes like stink again.Just wish ide phoned them sooner. A big thanks to Rpi for taking time out to talk to me they were A1.