3.3 ignition timing

[CO930]

I am trying to set the timing and was wondering what crank pulley mark needs to be lined up with the mark on the fan housing at 4k rpm’s? My crank pulley has a 10, 5, Z1 and 29 marks on it.



Thank you all again for your help.

[Zuffenwerker]

@4k rpm it’s going to be something like 26 to 29 degrees BTDC

[spuggy]

What motor type? What distributor is fitted? (US / RoW springs and thus advance curves are different).

Z1 is TDC, 5 and 10 degrees are used for setting the timing for some idle specs with vacuum attached.

29 BTDC is RoW timing spec for mechanical advance @4000 RPM with vacuum disconnected/plugged - believe this is correct/standard for a 930/60 like mine used to be ('78 RoW), but check your own spec books.

US spec is 26 degrees, pretty sure.

There's a whole different rigmarole around Cali or Japan-spec motors, which is where I think idle timing is used/significant.. They have extra smog equipment/different distributor again.

[Alan L]

You need to work out what systems/dizzy you have.
Alan

[CO930]

The distributor has two vacuum lines to it, one line goes to the throttle body and the other goes to the air recirculation housing/BOV. From what I know which isn’t much I need to use the USA specs.

[spuggy]

Originally Posted by CO930

The distributor has two vacuum lines to it, one line goes to the throttle body and the other goes to the air recirculation housing/BOV. From what I know which isn’t much I need to use the USA specs.

Seem to recall the two-nipple vacuum pot is the California distributor? Pretty sure "regular" (non-Cali) US and RoW dizzys only have the one port connected to the throttle body (which provides both vacuum and boost), and they differ only in the advance curve imparted by the springs.

I wouldn't take my word for it; I went Motec a few years ago and am rapidly (and happily) forgetting CIS...

Like Alan says, should probably identify engine type (decode the engine serial #), as having a Cali distributor is not exactly definitive (ran one myself for a few years). Then figure out what emissions equipment you have fitted or hooked up/working.

And then decide what to set the timing to. Too retarded, throttle response will be slug-like off-boost. Too advanced could be dangerous without knock detection/control.

[CO930]

The engine is 6881063 which appears to make it a Cali car. The smog pump system has been removed along with the EGR, Auxiliary air valve, Thermo valve, Cut off valve and Blow off switch valve.



So with the vacuum line from the dizzy to the BOV housing pinched closed do I use the 29 mark on the crank pulley and then line it up 3 mm before the mark on the fan housing at 4000 rpm to achieve the 26 degrees ?

[Zuffenwerker]

If you don’t have an adjustable timing light yes

[CO930]

Originally Posted by Zuffenwerker

If you don’t have an adjustable timing light yes

Yep no adjustable timing light.

[CO930]

The distributor cap on my setup seems to have a lot of movement, is there a fix for this?

[Alan L]

They all have a bit of play. Approx 1mm?
If you were really concerned you could put a dab of RTV under the lugs when you pop it back on. That should set if til you pull it again. But I have never heard of anyone doing it. Out of interest while have timing light on you could twist it back and forth and se how much effect it has. 1-3 Deg?
My dizzy has 1 vac line - ROW type 68 engine.
Alan