Cold weather starting

[btoscano]

Hey all,



I've noticed that my '93 W250 is not as winter friendly as my former '90 D250. Both start right up without a plug in. However, the '93 idle a little rough. If I push the accelerator pedal just a hair, it smooths right out and sounds like it would if it was warm. I am not sure if its a low idle problem because of pump timing or idle adjustment, or maybe just thicker oil dragging down the the idle?



I use 5w-40 synthetic in both. However, the '90 got Chevron 5w-40 CG-4 rated which I am out of so now I use Mobil Delvac 5w-40 CI-4+. The CI-4+ oils are definitely thicker than the older CG-4 oils. I am not sure if this makes much difference though.



Like I said, if I just barely touch the accelerator pedal, the rough idle goes away.



Happy Holidays,



Brian

 

[paccool]

If the idle is slow, the engine can run a little rough. Can you raise it up a bit and cure the rough running?

 

[btoscano]

I haven't tried to boost the idle yet. Before I go changing the pump I wanted to identify if its the cause rather than something else. Maybe I should get one of those tachs from Isspro that I've been meaning to get.



Brian