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Spark??
ibakes - 1/6/07 at 07:55 AM

Morning

Is there any reason why when the spark plug is fitted to the engine and I attach the timing light to a plug lead the light will not be overly reliable? sometimes not work at all, or miss every other spark.

but when the spark plug is resting against the block the timing light is perfect?

Having trouble making it run nice at the moment

02GF74 - 1/6/07 at 08:08 AM

yes. when the plug is inside the engine, the spark is attempting to jump the plug gap in a compressed atmosphere that has fuel vapour. I believe that is less favourable than when it is resting on the block when all it needs to do it jump across air at atmospheric pressure.

The lamp is triggered off by the spark so the spark is not occuring.

Over fuelling may result in petrol shorting out the spark plug contacts so no or intermittent spark.


What do the plugs look like colourwise?

ibakes - 1/6/07 at 08:14 AM

The plugs are sooty, and I know I’ve got to get the fuel down, but this also happens when the MS unit is not attached.

Defiantly food for thought tho

Agriv8 - 1/6/07 at 09:35 AM

Assume you are using a coil pack of some sort ( which one ? )

I have 3 timming guns 2 of which would not work with my waisted spark coil packs ! on the v8

A general consensus is that.

1 cheep timming guns with 'No timming advance features' are Ok.

2 Middle of the road guns with 'timing advance' seem to be problematic.

3 Expensive timming guns with 'timming advance' seem to be OK

Regards

Agriv8

ibakes - 1/6/07 at 11:15 AM

Appologies and using edis 4 unit

and think its snapon with timing advance (borrowed from me brother)

rusty - 1/6/07 at 11:16 AM

Are the plugs new and gapped correctly also are the leads and connection in good condition, is the coil pack well earthed.

Agriv8 - 1/6/07 at 11:21 AM

quote:
Originally posted by ibakes
Appologies and using edis 4 unit

and think its snapon with timing advance (borrowed from me brother)


MMM thats a catogory 3 gun

Have you got the pickup facing the right way ? ( the clip that you place round the ign lead ) there should be an arrow this needs to point to the spark plug.

regards

Agriv8

ibakes - 1/6/07 at 11:55 AM

quote:
Originally posted by rusty
Are the plugs new and gapped correctly also are the leads and connection in good condition, is the coil pack well earthed.


Not new but seem to give a nice spark when out of the engine

but the coil pack is loose where ive been playing around so probably not...


quote:
Originally posted by Agriv8
quote:
Originally posted by ibakes
Appologies and using edis 4 unit

and think its snapon with timing advance (borrowed from me brother)


MMM thats a catogory 3 gun

Have you got the pickup facing the right way ? ( the clip that you place round the ign lead ) there should be an arrow this needs to point to the spark plug.

regards

Agriv8


Have to check when I get home

ibakes - 1/6/07 at 05:27 PM

Right tried all thoes and pretty much the same really still it fires up

runs like a bag of poo but hopefully that is just due to overfueling (only just to get it started) as not tuned it at all must get the o2 sensor reading correctly

thanks for all the help

[Edited on 1/6/07 by ibakes]

DarrenW - 7/6/07 at 11:31 AM

Snap on advance timing light worked well for me. Ive got an old one with digi display. Only thing i had to remember is that it reads double due to being wasted spark, apart from that was good.