My merc benz sprinter 312D was switched off and tried to restart in 5 mins and refused to start. The engine was shaking too much, we checked if the diesel pump was getting power and it was. i have called more than five different mechanics they cannot get it right. One guy brought a diagonistic machine and it gave a code P1223 and research gave me the idea that the problem was the diesel pump. They replaced it and still it wont start,we have changed computer box and it didn't help.All these attempts have been done at a cost and it has sucked me dry.I am in South Africa based in Krugersdorp, Gauteng . I am not prepared to spend money on guesswork diagonisis anymore.I am asking for any advice ,info or a good mechanic who can start the vehicle. My mobile is available via PM or email. suggestions are welcome.i am sorry for being ambiguous maybe.

I've done a bit of hunting about and according to wikipedia the Sprinter 312D has an OM602 engine. Can you confirm this? (The engine number is usually stamped on the block near to where the injector pump lives)

If you have an OM602 here's a link to the factory service manual FSM - loads of reading sorry - but describes how to fit the injection pump

http://www.startekinfo.com/StarTek/outside/11832/Resources/201Create/PDF/70006.pdf

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I did a Google Search "computer code P1223 on a 312D sprinter" and some links came up. I don't know if there is a solution there.

Also there is Sprinter Forums.

Someone in the past on this Forum had a Similar Question but it never got answered.

Not mentioned is if you changed the Fuel Filters or know if the Fuel Tank Screen is plugged or not.

Old Fuel lines or if you have the type of lines that have Seals on them can allow Air into the System and that can create all kinds of problems.

Bad electrical Grounds (Earths)/connections can cause all kinds if weird issues with Electronically controlled items.

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84 300D, 82 Volvo 244Gl Diesel

This looks to be one of the Sprinter Forums:
mercedes sprinter 312d diesel problems - Sprinter-Forum

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84 300D, 82 Volvo 244Gl Diesel

I looked at buying a Sprinter and the forums are no where near as busy as these are.

Begin with some basic things and see if you have fuel at the injectors when the engine cranks. Make sure that you have fuel to the injection pump. Track down and test for correct fuel pressure.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Thanks guys for your help I will study how to fit the pump and give it to a good mechanic, i forgot to mention that diesel comes to the injectors but at a very low pressure its drizzling instead of spraying, the pressure is not enough to open the injectors. We do not know if the problem is the diesel pump sensors or the wires leading to the sensors.

If you can confirm the type of engine and the type of injection pump then there's a chance we can help.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Stretch, the type of engine is OM602 (312D) and the type of pump is Bosch I will check for further pump specifications when I reach home.

I am also trying to open that link you sent me Stretch, but im struggling to open ,not sure if maybe its my internet connection.

Great stuff - with that in mind then I suspect you have what is essentially a mechanical injector pump (hopefully the numbers on the ID tag on the pump will coincide with a type we can identify!) with bits of electrickery attached to it which means that if =>

<= then the fault is most likely due to the electrickery surrounding the pump rather than the pump itself.

The link I gave in post#2 describes a mechanical governor and an electromagnetic (controlled) governor which if you happen to have could be the part that is essentially stopping the fuel getting to the pump and therefore the injectors.

Furthermore there's additional information regarding the fuel delivery system and how that works with or without fuel heating elements etc. Hopefully you will be able to figure out which bits are fitted to your Sprinter and which bits are not.

First job is to identify that IP - there might be two tags on the side of it. One for the pump and one for the governor => two tags on one big lump or what looks like one unit.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I agree with you Stretch on that the problem is with electricity surrounding the pump, because if it was a mechanical fault it was supposed to show signs before it stopped. Do you think it is the wires leading to the sensors on the pump or the sensors themselves or both? Maybe further describing the location of the sensors on the pump might be of help. The has got two sensors ,as the side of the pump with a gear(the one which goes on the timing side of the engine) is facing away from you ,on the top left there is a sensor(black and rectangular in shape) bolted to the pump by four bolts and it has got seven wires leading to the ECU(computer box I think).Then at the back of the pump below the pipes which feed the injectors with diesel there is another sensor with only two wires.

Yes I agree with you Stretch on that the problem might be with electricity surrounding the pump ,I called my son at home to give the number on the pump and the number is 029983231A , I am not sure if it will help to identify the pump and its a Bosch as I mentioned before. The pump has got two sensors ,the other one is on the side of the pump (black and rectangular in shape) bolted by 4 bolts to the pump and it has got 7 wires leading to the ECU ( computer box),the other one is at the back of the pump bolted by two bolts with only two wires also leading to the ECU I think.

You could simply post a picture of the Fuel Injection Pump.

As long as the Fuel Injection Lines are not connected to an Injector the Fuel is going to dribble out because it is the Injector that holds back the Pressure. Think of the Injector as a pressure relief Valve. The pressure riseses in the Fuel Injection Line until it overcomes the tension on the Spring inside of the Injector.

Although it is gradully Changing the bulk of the really detailied Info on this Forum is about Diesel Engines used before 1986.

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84 300D, 82 Volvo 244Gl Diesel

Diesel 911 thank you also for that observation that the diesel won't spray as long as the fuel pipe lines are not connected to the injectors.Then I have got 2 questions concerning that.can a finger be able to block the diesel pressure from the injector pump if the fuel lines are not connected to the injectors?.2.if the fuel lines are connected to the injectors and an injector is removed from the cylinder head where it is bolted ,when cranking am I supposed to see the diesel spraying or not.I think your contributions will help us start this vehicle soon,thanks a lot guys.

312D sprinter should have a Bosch VP distributor pump if that helps