Spark plug gap's must be right!!!

[Robs]

Just found out the cause of my punto not idling right by measuring them.
The gap should have been 0.08mm but they were way off by 0.02mm:bang: using a spark plug measuring tool.
Easy mistake when having a service,so i'll be doing that myself!

 

[fingers99]

I have my doubts. 0.02mm is next to nothing. My digital verniers will resolve down to 0.01mm. If you can determine 0.02mm with a sprk plug measuring tool you should be working for Cosworth.

 

[dave]

op means 0.20

 

[fingers99]

I thought it would be something like that, but I doubt that'd make a huge difference (unless, maybe, it was 0.2 too big -- coils might struggle to make a decent spark).

 

[Mozella]

I thought it would be something like that, but I doubt that'd make a huge difference (unless, maybe, it was 0.2 too big -- coils might struggle to make a decent spark).

A 20 or 25% increase in spark gap is highly unlikely to produce a problem at idle. Even the old Kittering ignition systems (mechanical points, fitted to nearly every car many years ago) would rarely fail to make a spark at idle.

At full throttle and at high RPM you might notice a breakdown in ignition performance, but modern ignition systems are so good that I doubt a slightly incorrect spark gap is the OP's real problem. Certainly you wouldn't expect it to show up at idle.