How do you test a Injector Pump 1987 300D

 

It would be better if you just told us what problem you are having that may be caused by the Fuel Injection Pump.

There is 2 systems on the Fuel Injection Pump. There is the Fuel Supply/Lift Pump bolted on the side of the Fuel Injection Pump. The Fuel Supply Pumps the Fuel from the Fuel Tank and supplies it to the Fuel Injection Pump.

The Fuel Injection Pump supplies high pressure Fuel to the Fuel Injectors. When the test the Fuel Injection Pump in a shop the put it on a special made and very expensive Test Stand and check the calibration of the Fuel Injection Pump compared to the Bosch specfications.

 

do you know how to remove the supply pump from the side of the assembly? I think mine has failed, it barely runs and there's no bypass fuel coming through at all. Is it repairable or do you need to replace? thanks.________
VAPORIZERS

 

After you remove the exterior Fuel Lines I believe there is only 2 (3 on my year and model) nuts or bolts that hold it in. Just back them of a little and go to the other side and back it off a little and alternate like that until it loose and it easily pulls out.
The reason for alternating when loosening and also when tightening is that it may be under Spring Tension and it can crack the Flanges if it gets cocked (the cracking more likely to occur when installing the new one).

 

Are you sure that the Fuel Tank Screen in the Bottom of your Fuel Tank is not restricted or plugged?
I have also assumed that you changed the little Primary Filter.
I am not sure if your year and model has the Primary Filter attached to the Fuel Inlet Hose or you have the one that goes into a spot that is built in to the same Housing that the Secondary Spin-On Filter screws into.

 

OK thanks for the info. I wonder if it is possible to fix it, ie replace seals or o-rings or something like that? Or maybe I have to get another from the junk yard, probably should anyway and maybe recond that one b4 swapping them.

Also if you remove it, does it need a new gasket? Ie if I remove it maybe I can't put it back and drive the car unless I have a new gasket ready. But these merc's usually seem to have rubber seals rather than paper gaskets, eg the thermostat.

Re your other querie, I actually have a veg oil conversion. It barely runs on diesel without any fuel coming out of the by-pass, but doesn't run at all on veg - I think it must be borderline and can barely pump enough of the thinner diesel to feed the injection pumps - I just read on this forum somewhere that 95% of the fuel bypasses the injectors and is returned, so it must be barely working.
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GM 60-DEGREE V6 ENGINE

 

There is sort of a rebuild kit for the Fuel Supply/Lift Pump; it has 2 plastic Valves and 2 valve springs in it. What is missing is the tiny O-ring that does not come in the kit.
However, You can take your Fuel Supply/Lift Pump a part and see if there is any thing gunked up inside or if the little Valve Springs are rusted through.
You will need a 30mm Socket or Wrench to remove the large Hex Plug on the side of the Pump so you can look at the Pump Spring and see if it is broken.
The other Plugs I suggest that you remove and deal with one at a time.
The Copper Washers can be reused if they are not too mangled by hanging them on a wire Coathanger and heating them Red hot and letting them cool; that softens them.

If you remove the Fuel Supply/lift Pump you will most likely need a new gasket because it is rather thin and my rip when you remove the Pump.

You might disconnect the under the Hood Fue Inlet Hose and get an other length of Hose long enough to run into a searate container of clean Diesel Fuel. Pump with your hand primer to prime the Fuel Supply System and see how much Fuel you can get out of your Fuel Supply Pump like that. If you get a good amount out it is likely you have something plugged up.

 

That's a good idea to try feeding the fuel from a can - might as well make sure it is not starving fuel b4 the pump, before removing it and opening a can of worms. Both systems (diesel and veg) are not working properly so it would seem like a big coincidence if they both failed at once, but you never know given Murphy's law which seems to dog me incessantly. Great idea with the bit of home metallurgy to re - or would that be de-temper ? - the copper washers.

Where do you get the recondition kits, from the dealer? What is the tiny O-ring for? hopefully not the main seal for the pumping mechanism...
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Honda Cb-1

 

The heating a Copper Washer till red hot and cooling it idea so that you can re-use it came from a Navy Machinist Mate Manual owned by one of my past Boss.

In the Fuel Supply Pump there is a Roller Tappet that pushes a about 5mm thick shaft. The O-ring seals that shaft (the later model Fuel Supply Pumps with no Hand Primer are different). After that there is no other O-rings on the Fuel Supply Pump.

PeachParts sells the Valve kit for around $11 and what ever the shipping charge is.
The Dealer also sells it. But, no little O-ring in either kit.

If you want the complete rebuild kit (with all of the parts, O-ring and Copper washers and ect.) for the Fuel Supply Pump (there is a number plate on it) take it to the local Bosch certified Fuel Injection Shop and ask them if they would sell you one and for how much.
I believe the Fuel Injection Pump to Fuel Supply Pump gasket also comes in the kit but I would ask to be sure.

 

It took a while to find the below thread; there is a pic in there showing the little O-ring and other stuff.