My 'rebuilt' FI pump - sticking linkage arm

[jameshoward]

I sent my FI pump off for some work because it was filling up with oil thus causing the engine to run less well. It also caused the fuel economy to drop.

I have now received the pump back from the person who did the work. As you may have read in a previous thread, his solution to the problem of excess oil was to drill 2 holes inside the pump to allow for the oil to return. He has bench tested it and now wants me to run the pump on the car. I have to admit that the concept of drilling additional holes scares the hell out of me, but they're there now so I might as well get on with putting the pump back on the car.

However, when inspecting the FI pump today, I noticed that the arm that connects to the linkage and which has a spring between the pump body and said arm does not spring back into position when I push the arm forward. See attached photo of the part I am talking about. Instead of springing forward and resting on the stop, the arm sticks half way. I can push it forward by hand quite easily, but it is definately sticking.

Download Attachment: FIPump_Spring1.jpg
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Download Attachment: FI_Pump_Spring2.jpg
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I can see that the spring is small, and would guess that the other sprung part of the linkage on the other side of the rocker cover would be sufficient to drive it back to its normal position, but I'd like to know whether any of the FI pump ninjas think that this could be a problem.

Also, I am not even sure that the spring has been relocated correctly. From the position in the photo it looks a little random just stick where it is. Can I ask if someone else with a 230SL can see if their pump looks like this?

Apologies for the crappy photos. The first one has a thin red line pointing to the spring in question.

Thanks.

James

[mbzse]

quote:Originally posted by jameshoward

I have now received the pump back from the person who did the work. As you may have read in a previous thread, his solution to the problem of excess oil was to drill 2 holes inside the pump to allow for the oil to return

Sounds most questionable to me - like a workaround for something he did not understand how to fix properly
 

quote:I noticed that the arm that connects to the linkage and which has a spring between the pump body and said arm does not spring back into position when I push the arm forward.../.. Can I ask if someone else with a 230SL can see if their pump looks like this?

I enclose a pic of a 230SL 6-plunger pump. As you can see, the spring is an open one. Never seen a spring with cover like what´s shown on your photo
.

Download Attachment: FI pump 230SL restored_2.jpg
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/Hans in Sweden

[DaveB]

Mine also sticks halfway closed when the linkage is disconnected but, as you say, once the linkage is connected it does return to its stop. I guess yours will do the same.

DaveB

[Tom Colitt]

Hopefully he didn't remove the injection pump lever from its axle to do the "repair". Probably not, though. It is not uncommon for the pump arm not to return completely to the idle speed stop (also should not be changed), as there is friction inside the pump between the cam follower and the governor. Usually its not at the halfway point, but I would not worry beofre you haven't tried the pump out.

Regards, Tom

Tom Colitt

[jameshoward]

God only knows what he did. I have no idea. Now you mention it, Hans, I don't think mine had that cover there before. I did say to the gentleman that I seemed to have an oil 'leak' of sorts coming from there. Maybe he has looked at it and done something. As I said, whatever he did, I think he has bench tested it, as it drips light oil.

I am still waiting on some distributor rebuild parts (the think plastic plate/gasket that goes under the fly weights) and once I have those I can refit that (in the new and correct housing Cees kindly sent me) and then move the engine to whatever position is required to replace the FI pump. Since it's set up for the dissy at present, (the same position I removed the dissy at) I am too lazy to change everything then go back to refit the dissy once the bits are here.

Hopefully the bits will arrive tomorrow. I can then get things going again, if only in time to start the old girl and then park her up to go on leave.

Tom - grateful for your post. It makes me feel a little better. Thank you.

More to follow, but any points gratefully received. As ever.

JH

[Cees Klumper]

The pump on my car started sticking a tiny bit a few months ago (not always returning all the way to stop, which causes a bit higher idle rpm's). I replaced the various springs on the linkages, and lubricated the one on the pump, and now it seems ok again. I also checked 12 or so of the FI pumps I have laying around, and as Tom mentions, most faithfully return to stop everytime, but some don't.

I hope the pump works well, with these holes added.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic