Mud-club

Vehicle & Technical => Discovery => Topic started by: gtomo2 on August 28, 2006, 17:21:03

Title: spark plug gap
Post by: gtomo2 on August 28, 2006, 17:21:03

anyone know what the plug gap should be for a 3.5 v8 efi as i am fitting new plugs but dont know the gap size

Title: spark plug gap
Post by: wing nut on August 28, 2006, 18:29:27

if your changing your plugs they should already come preset :lol:

Title: spark plug gap
Post by: gtomo2 on August 28, 2006, 19:02:12

I like to make sure they are corrcet. plus found the gap settings on the link you sent me. so do and it still flippen missing. dam sure its cyl on the passenger side at the back think that one is number 8

Title: spark plug gap
Post by: imspanners on August 28, 2006, 21:31:20

Is it EFi ???
If so, try dis-connecting each of the injectors in turn and noting if there is any  change to the engine note.
Unfortunately, it could be the injectors themselves playing up, in which case try swopping 2 over and see if the mis-fire moves with it.
However, the most common problem is worn camshaft lobes. Remove the rocker cover and see if the valves are opening by turning the engine over by hand.

Title: spark plug gap
Post by: Range Rover Blues on August 29, 2006, 03:15:37

On an EFi, in fact any V8 with electronic ignition it's 30 thou.  Later EEC engine may have been bigger.

Check the layout of your plug leads as no's 5 and 7 (passenger side) can cross-arc causing negative work in one of the cylinders.

Try a compression test and a vacuum test.  Misfiring at just above idle that dissapears at higher loads/revs is an air leak.