Hello folks, new guys back. the 1978 244 that I've found myself with has a slight miss at idle, and failed smog due to the timing being WAY to far BTDC (22'), car seemed to be running happy at 22' BTDC and I've read this isn't unusual for them to happy out of spec. either way, spec is 12' BTDC and it wont pass smog unless i get it there.

now for the complicated bit. I threw a timing light on it, loosened the distributor, and with the dizzy turned as far advanced as i can get it, we're comfortably at 15' BTDC, but that's all she got. car still runs alright and still has a slight miss.

best i can figure the vacuum advance on the car isn't doing its job, because bottomed out in the advanced position should be far less that 15 BTDC. however all my experience is on old American V8's and maybe this is just how these distributors are? any help is appreciated

 

If your problem is you can't retard the timing enough to set it where you want to because you are at the end of the adjustment slot -

Take the distributor out and move the drive gear one tooth the direction you need/want it to be. (remove the bolt, remove the cap, line up rotor button to notch on distributor - for a reference point - pull the distributor up enough to disengage the drive gear, move rotor button on tooth the direction you want it to go and reinstall distributor)

Where is the country/world do they still test emissions on a 1978? And what readings is it failing?

 

I suppose that's the only answer, what I cant figure out is how the previous owner smogged it, as this distributor looks like its never been out of the car

and unsurprisingly, its California. that's where their still smogging 78' Volvos
it passed all the emissions with flying colors, it only failed because they checked the timing and found it at 22 when the spec is 12.
I think I'll see how it goes at 15' and if it fails again, I'll take it back apart

thank you for the fast reply

 

Do they use a strobe timing light and view the timing marks on the cam belt cover and the vibration damper?

It is common for the outer pulley of the vibration damper (that has the timing marks on it) to slip or spin - eventually they slip so badly it can sound like a loose fan belt.

 

I believe that's how they told did it, but I have no idea, I didn't see them check. not sure how else they'd do it

and I had the pully off of it yesterday, the locating pin is still there and its bolted down tight, might take the pully off and see if I can spin it at all towards the 12 degree mark, there's a little bit of play if I remember correctly

 

Just hand rotate the engine to bring No. 1 up to TDC . Check the timing marks and you will see if the harmonic damper outer ring has slipped.