Idle speed is electronically controlled. There's a dial just inboard of the brake booster that sets idle speed in 20- or 50 rpm increments. Pull the dial out then set it to a higher or lower number. If the engine responds, keep looking for a problem. It the engine doesn't respond, you might have a bad OVP relay or some other problem with the electronic idle system.

Sixto
87 300D

I put the ELR (idle dial on differant settings and it doesn't change the idle speed on the tach it's always about 650-700RPM

reving the engine in park or nuetral doesn't kill it
but it was bucking alittle when starting it the first time of the day

I would like to get this thing timed properly
ever since I got my I.P. "serviced" it has not been as good
I used to touch the key or think about touching it and it would fire in half a second
new starter
optima yellow top
new alt plus voltage reg
new OVP
new kima
belt