My 90 560SELfailed due to 950 rpm idle and 30 degree advance, but passed the emissions with ease. Car runs great! I was directed to the EZL, but I can't prove it is causing thehigh idle. I don't have a spare, I'm trying to really find the fault due to the cost of an EZL, $$$. There's got to be some good techs who can help me sort through this and pin point what's wrong. I was directed to R16 and that made added a lot of fun to this.

I pulled the plug on the idle air valve and the idle shot way up.Idle does go down to 650 when I pull the vac off the EZL. It

Here's what I found with my EZL:
1)TDC sensor ~800 ohms engine cold (50degrees F, California), ~1050engine at temp. Expected, I think resistance in copper wire is heated. I expect a lot of windings in a magnetic pickup.

Below are all at idle in Park:
2) Removing vac drops timing to one of 5 steps set by R16 settings: 5ATDC, 0, 5 BTDC, 10 and 15. You can get three easily: R16 in (0, 5, or 10 BTDC), R16 shorted (5 ATDC), R16 pulled out (15 BTDC).
3) Applying vac at idle jumps the timing from one of the 5R16 stepsto ~25btdc then in 8to10 seconds later it jumps to ~30btdc.
4) From the R16step, EZL timingadvances smoothly as vac is increasedfrom <~10lbvac down to ~40lb vac.
5) EZL timingjumps in steps as R16 goes from 0 to ~3k ohms. (That is the full range of my EZL response to R16 resistance change.)
4) EZL respondsin 5 timing jumps of timing to 5RANGES of resistance:
0 - 145 ohms ~4atdc
150 - 330 ~0 tdc
350 - 675 ~4btdc
680 -3.0k ~10btdc
3.2k -0pen ~15btdc
5) R16 must be available in4 resistances about 100, 200, 512, 750, (and maybe 3.5k).
Mine measures 750, it is color coded 750and part# 000 540 24 81 I think Bosch 09 8659 24. That putsmy timing at 10.Shouild it?

Now I wonder if the smog tech should have pulled the vac line to expect 0TDC. And my R16 would need to be ~200 ohms do do that. And, Why hasn't this come up on earlier smogs?