92 300D 2.5 won't idle on cold start,low idle speed on cold start - Page 2 - PeachParts Mercedes-Benz Forum

compress ignite · #16 07-09-2009, 02:22 PM

Even if your erratic idle is later found to be dirty injectors (or Timing) or a weak
lift pump,or a weak return pressure relief valve spring...the mechanical idle is
no big deal to correct.

klipweld · #17 07-09-2009, 02:36 PM

I will let it cool down and try it again. Then I can see if it's better.

compress ignite · #18 07-09-2009, 02:43 PM

At a Minimum.
Then you should be able to just plug the ELR connector back in and she'll idle
on her own...'should be no need to let it "Cool Down".

compress ignite · #19 07-09-2009, 02:52 PM

Redline 85 Plus will help clean out a lot of the Carbon built up in the engine's
internal combustion section [AND most Importantly clean your Aged Injectors!]

A Diet of: RedLine 15W40 Synthetic or Royal Purple Synthetic will "clean out"
all the internally lubricated engine parts.

klipweld · #20 07-09-2009, 04:10 PM

I just started car and checked the adjustment I made, with the ELR plug off, it's right at 600 RPM's on car tach. Car temp. was at 50C temp. It did not shake or bounce RPM's around. When I unpluged ELR plug ,I didn't really notice much of a change in idle. As for the ac on test, my ac compressor is not engaging, fan blows, but there is no jump in idle speed. So I don't know what's going on there. The AC will be another thing for the list, I guess. Just to get it starting and running good first will be a acomlishment. I will get back on here later after I start it from cold. Again thanks, Charlie

compress ignite · #21 07-09-2009, 05:01 PM

600RPM is in "Sweet Spot" for unassisted Idle.

'Nice job.

A/C non-engagement may be low refrigerant level.

Also,let us remember the dash tachometer is approximate measurement...
(that's why the FSM requires the Tech to use all the fancy additional tachometer equipment)

klipweld · #22 07-09-2009, 10:14 PM

I did wait till engine was cool and did a start. It is now what I would call a little rough idle at cold start. It didn't die. I can live with that untill I go through a list of recondition or "new car to me" items. I want to try the Diesel purge, check the timing chain stretch . I have more reading to doon this. I still have the oil and trans and filters to do yet. I bought mobil 1 synthetic for the engine, is there a recomended trans. fluid. I got the car washed up tonight, need to do inside next. Thanks once again for your help. Charlie Klippel

compress ignite · #23 07-09-2009, 11:37 PM

Then they changed their Synthetic Motor Oil Formulas to match the Newer
BlueTech style lubrication requirements (Not enough "Flat Tappet" protection
for our older style Camshaft Systems)

Then they changed their ATF formulation...

Red Line offers a Superior ATF Mercon fully Synthetic Racing Style formulation.