Hello. I'm looking at a 300SD that has low power off idle. Power comes on once the RPMs get up there. Could this be injector timing? Valve adjustment?

Any ideas?


Thanks!!

Randy

ALDA to turbo line cleaning could be a really quick fix.

dieselgiant has a great wirteup on it.

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Thanks! Looks like I should do that to my other diesel!


r

You should also adjust the Alda screw. I had the same issue. Valve adjustment, IP timing and new injectors helped some. However the biggest difference came from the easiest thing. Theer are several posts on how to do it.

OK, I just drove the car and it's idling real rough. There is no power off the line. It feels like it wants to bog down but once the revs get up to about 3k power comes on real good; I would guess the turbo is kicking in. The car has only 170k miles. I would guess it's nothing serious but ALDA, choked lines, possibly injection timing. Does that sound right?

Thanks!


r

Filters?

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Definitely check the air filter, and the inline fuel filter.

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'83 240D with 617.952 and 2.88
'01 VW Beetle TDI
'05 Jeep Liberty CRD
'89 Toyota 4x4, needs 2L-T
'78 280Z with L28ET - 12.86@110
Oil Burner Kartel #35

http://i16.photobucket.com/albums/b1...oD/bioclip.jpg

A history of the vehicle would be appropriate. Did it always have low power off the line, or is this a recent development?

When was the last time the valves were checked for lash?

When was the last time the camshaft was checked for timing?

When was the last time the IP was checked for timing?

How do you know it has low power off the line? Compared to what? The 617 always has "low power" when compared to the power it produces when on boost. You might be looking at a completely normal situation and have unrealistic expectations. Or, you might not..........if you have driven a properly running vehicle with a 617.

Without some answers to these basic questions, all of my compatriots are simply grasping at straws. Your problems could be just about anything or they could be nothing at all.

Don't have a history of the vehicle as I'm looking to buy it. I own 3 MB diesels and have a pretty good idea of how they can run, and yes, I realize they are slow out of the hole. This one is exceptionally slow, though. I'm not sure it would make it out of a sloped driveway! Just no power at all off idle. And thank you, everybody, for the suggestions. You all have pointed to a few things that wouldn't have occured to me. That's the thing I love about this group! Within minutes of posting I was getting suggestions. It gave me confidence that this thing could be made to run strong without a major expenditure. Thanks y'all!!


rr

Rough idle and low power in the lower end of the band can be any number of things. You're on the right track I think with the first two items. Leave injection timing off the list for now. I would say in this order:

Alda clean, adjust.
Filters. Air and fuel.
Valve lash check and adjust if necessary. While you're in there you could estimate cam timing--search for chain stretch.
Crack injectors at the fuel line and see how it affects idle. If cracking one does not affect idle, then switch that injector to another hole to see if the problem follows injector.
To determine if it's tank screen, rig up a gallon jug (wesson jug works great) with fuel lines and fill it with fuel and run the car on that fuel cell. If it runs better, then remove and replace tank screen and discard old fuel.
Lastly, if none of these work, run a compression check with leakdown to see if it's rings or valves that are burned or won't seat properly.

I've been where you are, except I went ahead and bought the car - pretty cheap, but I think I still I put too much faith in the fact that once the car got up to 3k rpm that it ran really good. I learned these ain't like gassers. Low rpm rumbles in gassers are usually little things like cap, plugs, rotor, ignition timing. I never thought I'd be replacing the head a few months later. Good luck!

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1998 E300D, 287k, barely broken in.

Griesl,

Very helpful! Thanks!



rr

hmm im curious.... Is this particular SD white, 1983?

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Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed