Injection pump on a 300sd has a small device on the injection pump ,it rest between the block and the pump and has a thick wire that runs to the interior somewhere.My other cars lack this piece ,what is it and where does it go?

What color is the wire?

and/or can you post a picture of it?

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

What year?

My 83 does not have said wire.

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83 SD

84 CD

its a rack sensor for emissions control.

there is some speculation that you can adjust the idle with it by opening the passenger kickpanel and adjusting a pinned cap with numbers on it.

I don't know how valid that is though.

It's probably an 85 and the device is probably the same as is on an 85D It's a rack position sensor that controls the EGR and Klima relay. On the D it feeds to a computer on the right side of the passenger footwell behind the kick panel. It cuts out the AC compressor under heavy acceleration. Don't know what it does to the EGR.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Superficially it sounds plausable. Nice to know.

What year 300SD is it? If it is 86 or newer then it is probably the idle adjustment.

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Gary
OBK #37

1985 ,thought I had that ,have an 84 300d with it also.

Anyone know how this interacts with the EGR?

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----Adam

1985 300SD 322,000

I just opened one.

It cannot affect the rack at all.

glad thats finally solved!

My 84 CD doesn't have that either, are these California cars?

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83 SD

84 CD

Don't think it has anything to do with California. I think all 85 D's had them. Maybe it extended back to late 84. I think they just open and close the EGR and stop and start the AC compressor based on load on the engine.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

This too sounds plausable and adjustment may still be benificial for some users. Depends on the range of adjustment I supose.

Does it look like it just does this based on rack position or are other factors involved? I guess what I mean is, is it just a limit switch?

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----Adam

1985 300SD 322,000

YEs if you remove the egr it just disables it-you could even disconnect the wire ath the harness connection but theres no reason to-and also the part about the klima cutting out the compressor on acceleration--it gets the signal from the micro switch on the valve cover.

Theres a good thread about removing all the extra garbage on the left fenderwell when U remove the egr--and a vacuum like rerouting diagram.