PeachParts Mercedes-Benz Forum - View Single Post - EDS/ELR Idle Issues

Diseasel300 · #16 10-31-2017, 10:17 AM

So we're all on the same page with regards to the idle-descent problem, here's how mine was behaving prior to new caps (for reference, I have my idle set ~650 RPM):

When operating "normally", a quick blip of the throttle would have the idle return to ~750 RPM, pause for a second or so, then drop back to ~650 RPM where the idle is set.

When "misbehaving", a quick blip of the throttle could have the RPM drop to ~1000 RPM and quickly (3-5 seconds) taper back to 650, or it could have the RPM hang at ~900-1000. Sometimes it would slowly (we're talking 15-30 seconds) return to idle, or on occasion, it would just stick indefinitely (several minutes). No amount of throttle manipulation would get it to quit what it was doing, but unplugging the ELR solenoid would immediately drop to ~550 RPM where the mechanical governor is set. The "stuck at 1000 RPM" idle was truly a random occurrence, generally at traffic lights or drive-thrus where a small amount of throttle was required to move the vehicle, then remaining stationary. It's so random, that I've never fully worked out exactly what has to happen to make it stick. I know that slow speed and gentle throttle movements were required. Generally when it would stick, the RPM was less than 2000 RPM prior to the sticking event.

With the capacitors replaced in the ELR, the 'delay' returning to idle appears to be gone. When blipping the throttle, the idle speed drops back to ~650 RPM immediately, and without the pause at the higher RPM. Whether or not capacitors have solved the "stuck at 1000 RPM idle" issue remains to be seen. I typically had that behavior 2-3 times a week and while irritating, didn't hold a candle to the car rocking (that was REALLY irritating). If I make it a week or two without a "stuck at 1000 RPM" idle, we can assume the capacitors were a fix.