Plug chop after run

[abowie]

Nice run today.

What are people's opinions on the tune of the car?

http://www.projectetype.com/images/4.2_ ... 4_2014.jpg

[christopher storey]

My opinion is - you are well overdue for new plugs !

[abowie]

My opinion is - you are well overdue for new plugs !

They're about 12 months old and have covered about 600 miles.

Do you think they're lean, rich, about right?

[christopher storey]

Well, I was actually being serious. These plugs - look at the bodies and the washers - are in quite a state for such a low usage . Maybe it is an aberration caused by the lens, but the plug on the left appears to have a centre electrode which is eroded on the right hand side, and the centre plug is the same with in addition some erosion of the outer electrode . The gaps also look very wide , even if you are running electronic ignition . As far as colour is concerned, with modern unleaded fuels it is very difficult to deduce anything from them unless they are either very weak ( blistered ceramics etc ) or very rich ( everything sooty ) . Also, a plug chop has to be done by shutting off immediately after a full throttle run of several seconds . Going home after a run and then pulling the plugs will not really tell you anything

[abowie]

Also, a plug chop has to be done by shutting off immediately after a full throttle

Yep that's how I do it too. I agree, the gaps are set wide as I have an EDIS unit on the car.

Any one have any comments on the tune state? Are the front 2 too lean or is the back one too rich?

[Heuer]

After a lot of trial and error with the EDIS I set the gaps at .030". Anything larger produced no appreciable difference in performance and I could not be sure it would cause problems under high load/poor fuel/altitude etc. For the cost I would swap the plugs anyway and avoid anything involving rare earth metals