Fiat coupe ignition timing - conflicting information

[nosher]

Hi all,

My 16v coupe seems to be running with the timing set for firing on number 4 piston. I know all the available info says it should be No 1 firing but it is definately number 4 it runs on. I have checked on my Autodata disc, and other manuals, and they all say No1 piston is at the cambelt end.
I have checked and double checked: the crankshaft sprocket is at TDC, the cams are lined up with the timing marks on both sides of the sprockets - yet the distributor rotor points at number 4 plug! I even took the cam cover off to check the inlet and exhaust lobes, and it was set for the ignition stroke on number 4. The cams had sections painted red and green paint, if that has any bearing?
Anyway, I'm baffled by this, as the engine runs absolutely fine this way - so what's going on - can anyone enlighten me?

thank you,

Nosher

[Guy Croft]

The cam timing marks line up at TDC 1& 4 when cyl 1is on the overlap phase, ie: at the end of the ex stroke and commencement of intake stroke - both valves are open.

At that time cyl 4 is on compression/firing.

I know it seems odd but that is how it is.

GC

[nosher]

Thanks Guy,

I'd sort of figured that just from removing the cam cover and looking at the cam lobe positions - it would only ever fire on No4. Just can't understand why all the owners club information, and even the Autodata discs all declare firing on No 1 when all timing pulleys line up. Guess that none of them have actually looked at the marks and the cam positions, and had to build one up.
Anyway, thanks for confirming what I thought - saves wasting any more time double and tripple checking all the info again - should just trust the metal - it never lies!

Nosher

[Guy Croft]

Y'all got that right:

Golden Rule - trust what your eyes tell you - and your instruments.

(*Just like Flight 19...)

GC




* the truth is out there!