172 Cup - odd misfire

[skiptontweed]

My car misfires very occasionally and I'm not sure why.

It happens when the car is warm and I have noticed it only at low revs (2.5-3k) with the engine under slight load. Like if I accelerate in 2nd from low speed, or if Im creeping round a carpark in 1st.

It misfires once and then doesnt do it again for days. Its not a repeated misfire, it feels like just once cylinder decides not to fire but just once.

Sorry if Im babbling but its hard to describe.

The car has done 60k and the coil and plugs were replaced 15k ago.

Any ideas?

 

[RichCup]

Checked for splits in the leads? If an exposed cable touches the engine, you'll see a spark, and the engine will 'skip' like you've described.

 

[cliosportap]

ht leads

 

[skiptontweed]

cheers guys, I'll buy a new set of leads on see what happens.

:approve:

 

[Dean0]

I have a very similar problem on mind - low revs under load, It does not do it at all when cold though.

Did you change the HT leads and did that solve the problem?

 

[skiptontweed]

I have a very similar problem on mind - low revs under load, It does not do it at all when cold though.

Did you change the HT leads and did that solve the problem?

To be honest I havn't done anything about it yet. The misfire is very infrequent - I suspect a dodgy ignition lead (see advice above) so I'll change them as soon as I get round to it as the problem can only get worse.