Pagoda SL Group
W113 Pagoda SL Group => Electrical and Instruments => Topic started by: Fonzi on October 15, 2021, 17:20:41
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I am trying to learn and understand the r20y injection pumps (from 1969 280se) I have here, and would like to understand what the top solenoid (Bosch 0330101012 ) and bottom solenoid ( Bosch 0330101013 ) are supposed to do.
The pump that was in the parts car with good compression seems to have a bad check valve on cyl 4 but I wonder if it has other issues as I note the solenoids have definitely been off and make even broken. See the bottom solenoid in the background of the picture.
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Top solenoid is for fuel enrichment in the FIP. I pushest the rack forward. It always engages when starting the car cold or hot.
The bottom is called the fuel cut off solenoid. It is engaged by a micro switches on the firewall and transmission when at idle and 3 or 4th gear I believe. In don’t remember exactly. It was designed to cut down on air pollution.
You can read about it more in the tech manual.
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Thank you! So I should get 12v to the top one when cranking. Should 12v continue after I let off the starter?
I’m thinking I should leave the bottom disconnected when trying to get an old motor running. Eh?
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Yes. You should get 12v on top solenoid only when cranking.
Some people disconnect none, one, or both depending on their particular issue.
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Thank you!
Just curious, after cranking, what handles the enrichment while the car is warming up? Is there a wax bulb up top that somehow affects the amount of fuel that goes to the injectors?
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Correct. Do a search on “WRD” or Warm Running Device. Check out the tech manual. All the answers are there👍👍