Ignition timing on a 4.3
Ignition timing on a 4.3
Author
Discussion

Gnasher

Original Poster:

113 posts

291 months

Friday 25th April 2008
quotequote all
Can someone please help?

I was fitting new cooling hoses last night, and as I struggled with the 2 behind the distributor I caught the vacuum unit and the distributor moved.Obviously it hadn't been adequately tightened, then I saw the access to the locking nut and knew why.

I have put it back to where I guessed it was, the engine starts and runs, but I thought I'd better reset it properly. However the 'Bible' is a bit vague on settings, retarding for unleaded etc, and the only static settings I can find vary and are 6 or 8 deg before TDC.

I'm off to France in a couple of weeks, and I don't want to find after a long run I've holed a piston.

Any advice appreciated.

SteveD

rev-erend

21,623 posts

314 months

Friday 25th April 2008
quotequote all
6 or 8 degrees is about right .. best method is to set it to 28 degrees at 4000 rpm with vacuum hose blocked
or another method some do .. is to set the figure higher until it pinks .. and then back off a few degrees until it no longer pinks whilst driving..

I prefer 28 degrees myself but what ever methodf you use it should not pink under load going up a steep hill.

Gnasher

Original Poster:

113 posts

291 months

Friday 25th April 2008
quotequote all
Thanks,

The other thing I've been told is not to rely on the crank markings are, so I will check the tdc first.
SteveD

rev-erend

21,623 posts

314 months

Friday 25th April 2008
quotequote all
You will notice that TDC actually lasts for a few degrees.. and you have to find the middle..

griffter

4,143 posts

285 months

Friday 25th April 2008
quotequote all
Mine runs about 12deg with vacuum disconnected, but with 6 or 8 you should be safe.

dnb

3,330 posts

272 months

Saturday 26th April 2008
quotequote all
Finding the middle of TDC is easy enough. Use a fixed length of dowel in a plug hole and rotate the engine until the piston touches the dowel. Then rotate the other way until the same happens. TDC is the middle of these 2 points. I found the crank markings on my engine were spot on by this method.