Speedy misfire diagnosis

[maddogf3]

My mate showed me this one .
V12 Ferrari on 11 cylinders ,obviously one cylinder not doing its thing , but which one ? Howered (my mate ) walks up spits on finger and checks heat on every cylinder in about 10 seconds, about three cylinder to the spit. Number 7 cold , pull plug lead off a bit and listen for crack from lead if it cracks ( obviously got spark at the lead ) remove plug to check plug or investigate further . If the plug is just fouled up leave plug lead with an "Air gap" to the plug .You might get lucky and clear a fouled up plug. This particular Ferrari was started from cold and had fouled its plug up Howered took the offending plug out and cleaned it and it when on all day after that, not missing a beat. In the passed I have pulled leads off one by one with my insulated pliers to see which cylinder Ok on a 4 but on a 12 takes ages I was very impressed Just alittle more spit or substitute spit with water on your finger if the car has just been steaming around race track .

[Chucky]

We got high tech now and use Raytek Infra red guns to do the same thing.

Although we still have to resort to spit when you can't get the gun near the header!

[zefarelly]

what grade of spit ? I use SAE20 . . .gives a better fizzle

[maddogf3]

Originally Posted by Chucky

We got high tech now and use Raytek Infra red guns to do the same thing.

Although we still have to resort to spit when you can't get the gun near the header!

Its actualy better and safer for one, if you can use an apprentice to do it ! when he screams the least you know you have the correct cylinder

[R59]

Another trick is to get some of those little thermal strips that show the temperature, and stick one on the end of a long cable tie. Put it near the header pipe, look at the temp. One with lowest temp am not going bang. Saw this used by the engine men from Cosworth when Mr Herbert's engine refused to run on 10 at Jerez back in '99, (when I last did some proper work for a living!)

Cheaper than a Raytek gun. More technical than a spitoon, and cleverer than an apprentice.

Rob.

[maddogf3]

Cheaper than a Raytek gun. More technical than a spitoon, and cleverer than an apprentice.

Rob.[/QUOTE]
Yes it might be more technical . But I think you will agree that its not as quick ( it being acheived in seconds ) and just as accurate for misfire diagnosis . My veiw is what ever you have in life and motor racing is -- Any equipment needs to be easy to use, easy to get too, foolproof and reliable . If none of these are met then the stuff gets slung to the bottom of the toolbox or get hidden away never to be used again I would have said F1 mechs had temp strips in rear pocket or close at hand to use them or they were unaware of the spit trick .I was, up until last year I pulled leads off and I thought that was quickest most accurate way . Only trouble was I had to get insulated pliers . When I was younger I just pulled the leads off and faced the odd "Whack" as an occupational hazard

[TomS]

How does you mate take off the lead without insulating pliers then!?

[maddogf3]

Originally Posted by TomS

How does you mate take off the lead without insulating pliers then!?

It was me that took the leads off . You use those things called fingers again . If you are careful,only grab rubber cap and are quite insulated on your feet you dont get a whack not even with trany ignition and keep body parts away from car . As I said my bottle has gone now and I will only do it for money these days the other thing is , I have my insulated pliers in the box and they are bright yellow .Dont be scared ,have a go ( I look forward to you reporting back when you've done it )
Take care
Martin