Slow Idle After Initial Cranking - Page 2 - PeachParts Mercedes-Benz Forum

rg2098 · #16 01-09-2007, 09:23 AM

Quote:

Originally Posted by Knightrider966

.... I've yet to hear of anyone getting one of these out successfully....

I have to give whunter credit here. He managed it, barely, on my 300.

toomany MBZ · #17 01-09-2007, 12:36 PM

All linkage lubed? Filters, air and fuel? Having the car that long, these sound like silly ?'s. Don't mean to imply anything. Time for a compression check? I just had the injectors checked, (the '82) the're old, but good spray pattern and pressure, yet #4 was hanging up a bit, 260k miles, hard starting, lethargic till warm. Compression tester worked one time, so I don't have that info. Anyway, good luck.

JMan300sd · #18 01-10-2007, 12:36 PM

While my linkage is lubed, my air and fuel filters have not been changed since early 06'. I'll go ahead and replace them, but just for my own knowledge I would like to know how that might help starting the engine as well as the low idle on startup. I had a hard time starting this morning even though I backed out the RD pin even more during the day before.

toomany MBZ · #19 01-10-2007, 02:31 PM

Grabbin' at straws.

Tom Evans · #20 01-13-2007, 09:56 PM

Problem solved. Sorry it took so long, but we have been having some warm weather in the Southeast. It took until a few days ago to have weather cold enough to test my repairs.

I adjusted the rack damper. It was about 1 1/2 turns too far in. That cured the slow initial idle. I still had the hunting problem. I had previously adjusted the idle up a little in order to mitigate the slow initial idle. Once I got the idle back down where it belonged, the hunting went away.

I'm still going to try one of those block heaters in the lower radiator hose.

johntksr · #21 02-02-2007, 07:50 PM

I have a 82 300sd and the idle is around 800-850. I would like to tweak down just a little. Where is the idle adjustment?

Quote:

Originally Posted by Tom Evans

Problem solved. Sorry it took so long, but we have been having some warm weather in the Southeast. It took until a few days ago to have weather cold enough to test my repairs.

I adjusted the rack damper. It was about 1 1/2 turns too far in. That cured the slow initial idle. I still had the hunting problem. I had previously adjusted the idle up a little in order to mitigate the slow initial idle. Once I got the idle back down where it belonged, the hunting went away.

I'm still going to try one of those block heaters in the lower radiator hose.

JMan300sd · #22 02-03-2007, 11:32 AM

There is a relativeley large screw/pin on the engine side of the injection pump in the relative area near to the #4 delivery valve. You have to unscrew the locking nut first. If you screw in this pin it raises the idle and if you screw out it lowers it. I wish I had a picture. Youll notice that the screw acts as kind of a stopper for part of the linkage, thus the more the linkage is depressed the higher the idle.

johntksr · #23 02-05-2007, 02:13 PM

Today, I made an effort to fix the excessive shake at idle. I adjusted the Rack damper with a full clockwise turn. It did not make a visable difference. However, I took the old girl for a spin and the excessive shake was a little better...but not quite fixed. I reduced the idle from around 800-850 to 725-750. The excessive shake appears to be gone. I took the old girl for another spin after the adjustment and see no signs of exsessive shake. Also, power is still very good and she still starts right up. I guess I should drive it for about a week or so before I claim victory. But for now the shake is gone...

Quote:

Originally Posted by JMan300sd

There is a relativeley large screw/pin on the engine side of the injection pump in the relative area near to the #4 delivery valve. You have to unscrew the locking nut first. If you screw in this pin it raises the idle and if you screw out it lowers it. I wish I had a picture. Youll notice that the screw acts as kind of a stopper for part of the linkage, thus the more the linkage is depressed the higher the idle.

JMan300sd · #24 02-05-2007, 08:37 PM

Very Interesting....in my tinkering with the idle I have always found that engine shaking increases with a lower idle and vice versa. But, I am glad that you have it resolved.

johntksr · #25 02-05-2007, 10:31 PM

Oh yeah, Thanks JMan300sd for the location of the idle adjustment.

I understand what you are saying. When I was making adjustments to the idle, if I adjusted just a little low the idle was rough and if I was a little high the idle was rough. I think I have just the right adjustment of idle and rack damper position. Additionally, I noticed an improvement on the highway. Previously, I had noticed what I thought was an alignment issue when above 70 mph. However, today I had no shake up to 85 mph. Apparently, it was excessive engine shake...I am not sure what the correct term is for engine shake?

Quote:

Originally Posted by JMan300sd

Very Interesting....in my tinkering with the idle I have always found that engine shaking increases with a lower idle and vice versa. But, I am glad that you have it resolved.

mbzkid · #26 02-05-2007, 10:57 PM

These are cold, mechanically controlled diesels we are talking about...

A low idle when cold is OK, just give it some throttle until it smooths out and can run on its own. You could also upgrade to the new glow plug relay which will keep the plugs lit after start up.

Pug it in at night! Park it in the garage! Glow plugs, injectors, filters (air, fuel), fuel treatment, starting and charging systems, idle speed, lube linkage, synthetic oil(maybe), linkage adjustment/throttle stop...