Need to Pass SMOG, high idle and advance.

Mercedes Benz Forum Mercedes Classifieds Photo Gallery Member List Search Mercedes History Sponsors Contact
Mercedes Benz News Calendars Forum FAQ Mercedes Recalls TSBs Timeslips Register Login

Need to Pass SMOG, high idle and advance.

Printable Version

Mercedes Forum >> Mercedes Benz Models >> Mercedes S Class >> Need to Pass SMOG, high idle and advance.

Page: [1]

Message

<< Older Topic Newer Topic >>

Need to Pass SMOG, high idle and advance. - 12/16/2006 8:35:40 PM

garymand

Posts: 10
Joined: 12/16/2006
Status: offline

My 90 560SEL failed 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 the high 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), ~1050 engine 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 5 R16 steps to ~25btdc then in 8 to 10 seconds later it jumps to ~30btdc.
4) From the R16 step, EZL timing advances smoothly as vac is increased from <~10lb vac down to ~40lb vac.
5) EZL timing jumps 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 responds in 5 timing jumps of timing to 5 RANGES 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 in 4 resistances about 100, 200, 512, 750, (and maybe 3.5k).
Mine measures 750, it is color coded 750 and part# 000 540 24 81 I think Bosch 09 8659 24. That puts my 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?