cold starting problems / IP start of delivery on '84 300D - PeachParts Mercedes-Benz Forum

airbus · #1 02-05-2007, 05:51 PM

Quote:

Originally Posted by Stevo

I wouldn't try that "pulling the IP out a little, turning it away from the engine ", thing... Your apt to just "muddy the water", next step should be to time it and see just whats going on. Your are going to have to do that in the long run anyway, of course you could nail the "sweet spot" or hit the Latto

But I did try to find the "sweet spot" within the entire range of adjustment and I couldn't. There was always a steady stream coming out, diminishing to a fast dripping and after the pressure was gone it almost abruptly stopped. I pumped again and again with the same results, no matter how advanced or retarded relativ to its original position the IP was.
The engine was at exactly 24 deg. BTDC, all vacuum lines to the IP disconnected, throttle linkage fixed at full throttle with a piece of wire and fuel valve taken out of #1 element. Did I miss something?
However, I observed much better but still far from perfect "starting behavior" (still won't start below 20F) after I gave up with the drip tube and advanced the IP all the way.

Stevo · #2 02-05-2007, 07:58 PM

Quote:

Originally Posted by airbus

But I did try to find the "sweet spot" within the entire range of adjustment and I couldn't. There was always a steady stream coming out, diminishing to a fast dripping and after the pressure was gone it almost abruptly stopped. I pumped again and again with the same results, no matter how advanced or retarded relativ to its original position the IP was.
The engine was at exactly 24 deg. BTDC, all vacuum lines to the IP disconnected, throttle linkage fixed at full throttle with a piece of wire and fuel valve taken out of #1 element. Did I miss something?
However, I observed much better but still far from perfect "starting behavior" (still won't start below 20F) after I gave up with the drip tube and advanced the IP all the way.

Sounds like you need to step back and and maybe try another method. I use the drip method where you basally blow air through the IP while rotating the eng, when the bubbles stop, there you are, do a search on "drip method" Most folks here like the drip method but I could never get it too work and its messy

airbus · #3 02-05-2007, 11:03 PM

How big is the range, where the engine actually runs? Should it run, no matter how badly, with the IP at the furthest point away from the engine to the closest, or in other words from all the way retarded to all the way advanced? Mine ran totally crappy and smoked a lot with the IP approximately in the middle. I'm assuming if I had retarded the IP a little bit more, the engine wouldn't run anymore at all. Now all the way advanced it runs pretty smooth, definately better than before, when it was advanced approximately 3/4 the way.

Bruce Kennedy · #4 02-05-2007, 11:24 PM

If compression is a little low, no matter what you do you wont get it to run perfect when its cold, ie, you will have to stay with it till it warms up a little. All of my mb's are tuned; chain stretch, valves, ip timing, and new filters. My sd with 367k will start in the teens but I nave to stay with her for a little while. My td with 50k on the engine will start in single digit temps without ever touching the pedal.