GTV6 Ignition Issues

[Fylnn]

The GTV did its one and only rally for the year on Saturday, better do more next year.  It was a seriously hot day, some drivers ended on drips etc.  We made it to the end, but had a progressively worsening issue with what seems to be ignition.  Now there could be multiple explanations including the fuel map in the Haltech.  But the car has been running well for over a year until the white heat of competition.  My problem was it was fluffing and farting and not wanting to run down low and then breaking down at high revs.  I put new leads on it recently, so they should be OK.  The car had a tendency to foul plugs, and in the end we went to B6ES plugs and it has been fine since (for road use and short sprints) but on sustained hard use we had the problem above.

i seem to recall reading somewhere about leaded V6 engines having a problem with fouling plugs.  This will no doubt be an intricate investigation to find what is wrong, but is there an issue people know about in this regard?

[colcol]

Can't talk about V-6 engines, but of the same era, 33 and Sud engines ran good on leaded petrol, then on unleaded petrol, they had a tendency to foul the odd spark plug, those NGK B6ES spark plugs ring a bell, whatever NGK recommended, i went to one stage hotter, so it runs hotter and burns all the crap off the plugs.
Under hard driving or sprinting, you will have to take them out at the end of the day and make sure that they are not getting too hot and melting the electrode.
Under extreme conditions, they can run too hot and glow red hot and ignite the fuel at the wrong time causing uncontrolled combustion causing dangerous pinging.
It would be similar to having a lot of carbon buildup on the pistons and cylinder heads, and that glow red hot and cause random ignition of the fuel mixture causing damage to your engine, hope this helps, Colin.

[alfagtv152]

Hi Fylnn,
I have come across issues recently with NGK BP6es plugs going open circiut and not firing at all,not even firing a timing light when there was spark to the plug.These issues occurred with a 2L Alfetta and a 164 that just would not go until the plugs were changed.
Personally I swear by Bosch Super 4 Plugs in 4 Cylinder and 3L V6 Potenziata engine and have for many years.The range of vehicles include those above + super charged 2L,various forms of fuel injection and a range of leaded and unleaded fuels without any ever failing and to top it off I like another one of our members has witnessed an increase of 4HP just by fitting them in back to back Dyno pulls.
I would recommend WR78 or WR78X for good ignition systems(bigger gap),with the 4 earth electrodes it would pretty hard not to find one to discharge to and you don't have to worry about orentation to the valves.
They have been a little harder to find (and expensive) in Australia but easy to get from UK,I think I bought the last lot from timgreen880 http://www.ebay.co.uk/itm/6x-Bosch-Special-Spark-Plug-WR78X-/230794001932?ssPageName=ADME:X:RTQ:GB:1123
Cheers
Andrew

[Fylnn]

thanks, great information.  It has always been sensitive on plugs.  I will pull the B6ES this weekend and look at the electrode.  They might be too hot for competition.  Use B6ES normally and change to B7ES for competition perhaps.