1997 lantra si intermitent problem

[ray100655]

Hi all today mt lantra started to run lumpy as though it was not firing on all the cylinders so i replaced a the spark plugs it is better but not quite right notice it more on hills the engine is the 1.8 and manual gearbox with 103000 miles on the clock the crazy thing is when i first went out today it was ok went to the shop then when i started her again that's when i noticed the problem. any ideas what to check now whatever it is i think is a simple fix as long as you know where to look any help you nice people can offer would be most welcome

[jsinton]

Could be many things. Do you have a check engine light? Did you have a code scan?

[EdGasket]

If it is struggling under load, like going up hills as you say, then that is when the ignition is under the most strain as it is harder to spark under high compression. Have you checked your ignition leads as these deteriorate with age and the resistance increases. If you have a meter, measure the resistance from end to end. On a new set the resistance of the leads is around 4K to 7K ohms (shortest lead to longest lead) so if they measure over 10K ohms; get some new leads. A new aftermarket set cost me around £24.
On another car, I actually replaced mine with copper-cored HT lead. Cut the old ends off, screw in a narrow self-tapping screw half way then saw the head off, then screw the HT lead on to the thread and coat in araldite or similar. There are still suppressors in the end caps so I have no problem with radio intereference.

[ray100655]

thanks for the replies i have had no warning lights at all i have replaced the spark plugs which made it a little better and today i purchased a new set of ignition leads and will try to fit them tomorrow. if that doesn't do the job i suppose the next in line is the coil pack don't know how hard it is to change but will have a look what baffles me the most is no warning from this fault it was running great then the next time i started her up she ran sluggish kicking in to normal and back out again. anyway will try the leads tomorrow and let you know how things go thanks again for the advice

[ray100655]

hi all found the problem ignition leads although only one was bad i changed the hole set, car is running really well now, also changed the headlamp bulbs as one had gone. does any one know if there is a brighter bulb that can be used in the standard holder fitting as i find the original ones quite dim compared to some cars. any way thanks for the info £38 for leads and £4 for bulbs nice cheap fix. wish you all well