distributor vacuum

[jim 56]

My 280 SE M130 has late distributor.I have a vac gauge in line going from two way valve to dist.at idle it reads zero vac.When I open throttle it reads 14 hg is this correct and does this mean my emissions system is ok.I will try to time it this weekend(just got a new light)I think it should be 6btdc at idle 38 at 3000 correct?









?

[dirkbalter]

You will find a lot of information here.
https://www.sl113.org/wiki/Electrical/Distributor#SL280


However, if you have a late US version with the "emissions reduction system" you should have full vacuum at idle and no vacuum above 2500 rpm.

[jim 56]

I looked at the tech manual.mine is the last picture late 280.I can't understand it too well because my oil switch must be over 17 and my water is definitly over 100 deg.So it says my vac is cut off which it is.Then the next sentence says that at idle vac is applied to the dist it seems like it is contradicting statements.Like I said earlier I only get vac to the dist when throttle is opening I can hear and feel the two way valve opening.Vac does go away at around 2000 rpm.Maybe I have the two way valve hoses reversed?

[mrfatboy]

A couple of us were working on a fellow members car last November(69 280sl auto). It was discovered that the throttle body switch was installed upside down giving reversed readings.

Your problem sounds similar so I thought I would just suggest it so you can double check everything.

[jim 56]

Thanks I will check it out.