Where is it located on I.P. on OM603? Ive removed the AFM and EGR, but its always hovered around 600rpm idle, never died once, but shudders like hell! Thanks in advance

Idle control is managed by EDS through the ELR actuator, the round thing on the back of the IP. There is a trim adjustment by the brake booster - a dial with positions 1 through 6. Each number higher than the current position adds 25- or 50 rpm. Each number lower... well, you get it. If idle isn't smooth, maybe the idle system isn't working. Disconnect the ELR actuator. Idle should drop, possibly stalling the engine. If there's no difference, there's a problem with the idle system and possibly someone adjusted base idle to compensate. Something's not right if a 603 doesn't idle smoothly at 600 rpm. Do the tach, AC compressor and cruise control work?

Sixto
87 300D

Tach and ac work. lol. is this ELR actuator the box up in the cowl/firewall with an electrical plug in it? Thanks

__________________
Lotus 7 replica-20valve 4AGE
06' 500R Ninja Naked/Café/Custom
86' 300 SDL (Donor)
98' Discovery 50th anniversary (Recipient of transplant)

Sixto
87 300D

Just disconnect the two prong plug? I disconnected it at the knob end and it made no difference. Just changed fuel filter, and ran injector cleaner through it, seems alittle better. im thinking its the #4&#5 injector lines not pulsing. (dead injector lines thread). I think the poor thing just needs a good road trip with steady 60mph speed for an hour or two!? This put put to work once or twice a week isnt enuf to keep the battery charged even!

__________________
Lotus 7 replica-20valve 4AGE
06' 500R Ninja Naked/Café/Custom
86' 300 SDL (Donor)
98' Discovery 50th anniversary (Recipient of transplant)

If nothing happens when you disconnect the 2-prong plug, it's not getting a proper ELR signal. Look for the problem upstream. If the tach and AC work (Klima relay in place and functional), the problem isn't the OVP relay and fuse. Given the robustness of these engines, I'd carefully check the wires and connector at the ELR actuator. I'll bet you'll find a bad connection somewhere.

Sixto
87 300D

If the ELR isn't working and the idle is too slow, the idle speed can be mechanically adjusted. In the earlier picture just forward of the two prongs is the mechanical adjustment. Undo the locknut and adjust carefully and accordingly.

Another thought, if the SDL is shuddering at idle you may want to consider motor mounts.

Motor mounts are solid. but from what i hear they are fluid filled and if they're solid than the dampening of them is bad? Or what about the little struts down there? No one seems to ever mention them?

__________________
Lotus 7 replica-20valve 4AGE
06' 500R Ninja Naked/Café/Custom
86' 300 SDL (Donor)
98' Discovery 50th anniversary (Recipient of transplant)

The SDL motor mounts are not fluid filled. The SDL uses the same non-hydraulic motor mounts as the W123. The ones on my SDL were shot and the engine would shake and vibrate at idle particularly when cold. As I understand the shocks are more for dampening vibrations when the engine is shutoff. I ended up replacing those too as they both had virtually no resistance. After replacing those components the idle feel is much better. I still need to replace the transmission mount as I know that is worn out too.