MD17C rebuild

[Mark Maulden]

There is valve timing and there is injector timing. Valve timing is set by the mesh of gears between the cam and crank. It's not going to change unless some gear skipping occurs. Injector timing is set by shims under the injector pump that control when fuel is injected. This should not change unless the pump has been removed and gaskets changed or ? . Or the cam lobes to the pump are worn. So it's up to SC to say what has been changed if anything.

 

[sailcruiser]

There is valve timing and there is injector timing. Valve timing is set by the mesh of gears between the cam and crank. It's not going to change unless some gear skipping occurs. Injector timing is set by shims under the injector pump that control when fuel is injected. This should not change unless the pump has been removed and gaskets changed or ? . Or the cam lobes to the pump are worn. So it's up to SC to say what has been changed if anything.

Nothing has been changed besides oil/filter and fuel filters. I dropped off the injectors today and got a that all 3 had issues and needed new tips. It had been suggested to pull the injector pump at the same time but I couldn't see how that could be it given it ran without a problem for the first 18 months we had the boat. The only issue that was noted on the injector pump was a slightly loose bleeder screw allowing a very slow drip.

I don't have a clue how to compression test this engine. Are there more special Volvo tools in my future?
SC

 

[sailcruiser]

Hmmmm..Currently out sailing but back on sat... Looks somewhat white on an iPhone...either temp or low compression... Since u have injectors out, suggest a compression test.

To my eye it is light gray and smells strongly of diesel fuel. If the engine is revved high in neutral as when the mechanic was looking at it it left quite a cloud that looked white and some gray. The guy working on the injectors thinks the tips may be the problem, Time will tell. What are you thinking about the temp? I've never seen it even close to overheated.

SC

 

[Mark Maulden]

Compression test might be one of those you have hired out. Or talk someone into loaning you a gauge.maybe a tool rental co might have them. You just need to secure it as you would an injector.

 

[Mark Maulden]

How much oil are you going through?

 

[sailcruiser]

How much oil are you going through?

It doesn't burn much if any oil. It hasn't required adding oil between oil changes and gets checked before each start.
SC

 

[sailcruiser]

Compression test might be one of those you have hired out. Or talk someone into loaning you a gauge.maybe a tool rental co might have them. You just need to secure it as you would an injector.

Would this work with all 3 injectors out? Or is it a replace an injector with the tool and have other two in place? I'll talk to my mechanic about it when I call him next week.
SC

 

[Mark Maulden]

Well chances are if two are left in place, the engine will start. I would take them all out and pull the kill handle during testing...you could leave two in but be sure the fuel shutoff is activated. I think I stuck a socket between the engine and the lever that the kill cable pulls..

 

[sailcruiser]

We compression tested ok. The new injector tips have solved the majority of the issue. We still smoke a bit if the engine is throttled up quickly which I'm told is likely the injector pump. We will address that in the fall.

SC

 

[fredr]

While I understand that injection timing does not change, as you noted. It does sound like injection in a little late, and needs to be advanced. (remove a shim from under the pump.)

 

[Mark Maulden]

I would not try to remove "a shim". Shims that have been there for 30 yrs will not separate. They are basicly a fiber gasket. If multiple shims were used, they are probably one shim now. You might have to pry the pump out which could damage shim. If I were to do it again, I'd try and test the injector pump in place. Not sure if its possible but all yore after is pressure and quantity. The pump is basically 3 separate pumps so if they are the same, pump is probably good. You should also check the automatic cold start. It is disengaged by oil pressure via the external line going in by the governor. Disconnect it and put about 10lbs air pressure to it. You should here changing states.

 

[unbusted67]

Mark, This is a great thread. Thank you for all of your input. I just bought a contest 32 that has a MD17C in it with a bad injector pump. The previous owner has the engine apart up until the point of pump removal. I attempted to get it out today and failed. I got it to the point where it has separated from the block, I've probably got 15 mm of space but it is stuck and I am worried about scoring the mating surface or snapping the pump. Do you recall your exact method for removal and how hard it was? Is it connected to something inside the body of the engine? Manual diagrams do now show.

 

[Mark Maulden]

Boy, you sure drug an old one here. Hopefully, you didn't try very hard to lift the pump out once it was free. The "rack" is on the inboard side of the pump. Inboard wrt to engine and not boat..There is linkage between the rack and the governor which is on the opposite side of engine. The throttle actually controls the governor which in turn moves the rack on the pump. There is a little shiny stainless steel cylinder about the size of a small fingernail that has a to be removed to separate the linkage between the governor and pump. You have to get to it from the access plate that the fuel shutoff goes through. You don't want to drop it and have it get stuck somewhere. In all honesty, I did not perform that particular maneuver cuz I chickened out. But if you try it, I would try to lay a catch cloth of some sort underneath. I replaced my Volvo last year with a Beta 35 and I have all the parts that come off the block with low hrs. Actually, parts from two engines...Including a rebuilt pump. PM me if interested. If you wish, I can take some pix of this connector linkage. There is also a spring in there and I think that's for the cold start.

 

[unbusted67]

thanks mark. is sent you a pm

 

[unbusted67]

Hey all just following up on this. My injection pump was so badly seized that the rack became stuck and I was unable to remove the pump from the engine. I had to take the transmission off, drain the engine oil, and remove the gearbox cover in order to access the pump and governor, and cut the old pump out. I am now in the process of putting this all back together. Fingers crossed other parts of engine aren't in as bad shape.