Ignition timing way off

[TomoHawk]

I checked the ignition timing on my car yesterday (finally) and the mark (marks) are off the end of the timing indicatior. BTW- which mark to use; the one on the pulley or the balancer? Maybe one was filed in by a PO?

Anyway, the engine runs, but I had the distributor turned all the way to get the timing mark to about 20 degrees (at 800 rpm, without any vacuum advance.) If it was a V8 engine, I'd say the dizzy was installed with the drive gear a tooth off, but the L28 dizzy only goes in one way or the other (180 degrees different.)

I think a visit to the Nissan dealer to have the S30 guy look at the dizzy will be worthwhile. Maybe have him rebuild it?

Just getting it that close helped the engine run SO much better. Lots more power at any speed, and increased fuel mileage. I wonder how it'll run when I get the timing right on. :laugh:

Any ideas about what might be going on?

thxZ

[ChrisZ]

Maybe the drive gear from your oil pump is a tooth off.

Chris

[TomoHawk]

Can that ( moving the oil pump gear) be fixed without "taking the whole engine apart?" (refers to the FSM)

Ah... there's a note about how to set the distributor drive spindle and installing the oil pump, so I think the answer is yes, the oil pump can be (extracted from below.)

thxZ

Edited July 12, 2009 by TomoHawk

[sblake01]

If nothing has been changed by the PO, and that is suspect based on other things you've said in the past, you would line up the notch on the pulley with the marks on the timing tab. An L series distributor won't go in 180 degrees off since it's keyed off centre. The only way for it to be off the way you describe is the scenario that Chris mentioned.

Edited July 12, 2009 by sblake01

[sblake01]

Can that ( moving the oil pump gear) be fixed without "taking the whole engine apart?" (refers to the FSM)

thxZ

Yes, it can.

[TomoHawk]

OK, so the next question would be to decide which would be more apropriate as the next action:

1) Have the oil pump extracted to check the distributor drive shaft is correctly installed?

2) Have the distributor checked and questionable items rebuilt or corrected to get it correctly installed, since it is 180 deg. off?

thxZ

[sblake01]

I'd go with #1. The only way the distributor could be 180 deg. off would be if the oil pump drive is lined up that way. Seems like a lot of trouble for the PO or whomever would have removed it to have set the wires so it would run that way rather than just put the pump in right. Make sure the engine is a TDC before pulling the pump out to realign it.

[FastWoman]

Another vote for the one-tooth-off hypothesis, which is correctable from the oil pump side (although it is a slightly frustrating exercise -- did it on my old '75).

You asked: "BTW- which mark to use; the one on the pulley or the balancer? Maybe one was filed in by a PO?" It took me a while to find the timing mark on my own '78, but it is a punch on the outer margin of the pulley on the opposite side from the belt groove, rather than a notch that cuts across the pulley. I suppose they did it this way to keep the timing notch from wearing the belt. Nothing about it looks filed. Perhaps it was drilled instead of punched -- or at least on mine.

[Doehring]

Both my'72 240s run 32 degrees at 4500 rpm