I spoke too soon - Volvo MD11C

[Swanrad2]

I posted a while ago that I had fixed my MD11C - I had her running, was what I should have posted.

The throttle control on the block (rather than the Teleflex) is very stiff. It will move with some light tapping with a hammer but not with manual pull/push. I have sprayed it with quick release and left it soaking. I believe that there is some complicated stuff goes on under the throttle so don't want to take it apart if I dont have to, so from experience is spray/wiggle/spray likely to free the thing off or is it back to the mechanic man to strip and free up?

Also the cold start thingy (a spring on the top of the block) actuated again by teleflex cables seems stiff - anyone know how these things work?

Felt a bit like, solvent, matches, insurance claim this weekend when everyone else was polishing the last bit of stainless before launch and I was once again stuck with my back side in the air and my head in the bilge! I think the question 'ready to launch soon' should be punishable by public flogging.

Thanks.

 

[Jcorstorphine]

Sorry to hear of next problem. I would not use too much force such as tapping with a hammer. I recall opening up the fuel pump / governor on my MD2B to find springs and widgets. As there was nothing actually wrong I closed it up again.

The cold start is linked to the throttle so if there is a problem with the throttle then the cold start may not engage.

If you Google MD2B fuel pump details you will see what is inside. From there you can decide if you want to open it up or call for "a man with a spanner"

I know your engine is. A MDIIc but I am sure the pump is very similar

 

[Bilgediver]

I posted a while ago that I had fixed my MD11C - I had her running, was what I should have posted.

The throttle control on the block (rather than the Teleflex) is very stiff. It will move with some light tapping with a hammer but not with manual pull/push. I have sprayed it with quick release and left it soaking. I believe that there is some complicated stuff goes on under the throttle so don't want to take it apart if I dont have to, so from experience is spray/wiggle/spray likely to free the thing off or is it back to the mechanic man to strip and free up?

Also the cold start thingy (a spring on the top of the block) actuated again by teleflex cables seems stiff - anyone know how these things work?

Felt a bit like, solvent, matches, insurance claim this weekend when everyone else was polishing the last bit of stainless before launch and I was once again stuck with my back side in the air and my head in the bilge! I think the question 'ready to launch soon' should be punishable by public flogging.

Thanks.

The cold start button is just a spring loaded plunger . You should be able to depress it just lightly pressing
it. The throttle control is just a spindle in a bush with an operating lever in the governor housing.

It sounds like your engine was laid up for some time with severe condensation inside and you have got some
rusted components. You can see more by peeking inside by removing the plate on the back of the engine.

See page 34 in the manual.
http://www.bluemoment.com/manuals/VolvoMD11C_D_17C_D.pdf

To set the cold start you have to put the throttle/speed lever to around 1/2 and then press the button . You can see the
works after removing the plate on the back of the engine. May need to be an acrobat and or have a good mirror from the wifes
handbag

I think the speed lever just operates on a spring so waggling it should do no harm till it frees. Likewise the cold start is just a spring loaded plunger.

Something like Plus Gas might help release both the speed spindle and the cold start followed with a dose of 50/50
diesel and engine oil. Just keep working them and thy might come free.

If the cold start sticks down then you will probably have a very smoky engine.

I find it hard to believe that right through the overhaul no one tried moving these controls!!!!!! Are you sure the problem is not the teleflex????
I thought you had an injection expert helping

 

[Swanrad2]

We had a man in who changed the injector pump for me, he was in and out in a couple of hours...he didn't mention a sticking throttle control and because the teleflex is duff and needs replacing I never actually checked the control. This bit of the engine makes me nervous because of the potential to kill an engine that has now cost me a fair bit to get running again, so I think I will work it with the suggested mix (maybe take of the inspection panel and lubricate from inside as well). If this fails, back to the man.

The cold start depresses with reasonable force, I think when the cable is replaced it will pop back out as well - maybe just a bit of soaking. With a little leverage it pops back up.

Thanks,

 

[Bilgediver]

We had a man in who changed the injector pump for me, he was in and out in a couple of hours...he didn't mention a sticking throttle control and because the teleflex is duff and needs replacing I never actually checked the control. This bit of the engine makes me nervous because of the potential to kill an engine that has now cost me a fair bit to get running again, so I think I will work it with the suggested mix (maybe take of the inspection panel and lubricate from inside as well). If this fails, back to the man.

The cold start depresses with reasonable force, I think when the cable is replaced it will pop back out as well - maybe just a bit of soaking. With a little leverage it pops back up.

Thanks,

The cable only depresses the cold start. Usually the cold start returns due to the wee spring under the button. The lever doesn t
lift it. Well not on mine???

Yes lots of waggling and moving from inside and out could help. With the cover off you should be able to confirm that the internal operating
lever is following the external lever when you move it.

 

[Swanrad2]

I know this is a bit disjointed, sorry, work has picked up a bit. We had the inspection cover off the throttle assembly and although tight, there was no visible issues. Figuring the best way to to oil it all up and maybe free it off is to run the thing, we started her. A lot of cold start spray (the cold start button seemed to have no effect). The engine ran for a while before the revs picked up markedly (the exhaust fumes were still white so I don't think it ran away on sump oil). We weren't getting any water running through at this point, so we had to kill the engine. The stop control, although free and even sprung back didnt stop the engine. Cracking the injectors did.

We therefore seem to have a non-functioning cold start & engine stop lever and a stiff throttle assembly. There's sumthing wrong down there at the back of the beast. I have an engineer booked in a couple of weeks - anyone got any bright ideas in the meantime?

I think if I am refitting an engine in the future I will start by taking it out - regardless of the work/cost of doing this as I am sure we could fix whatever is going on down there if it was in a big dry, work bench. The engineer is being called in because he can do it in-situ.

 

[SAWDOC]

I have a vp md11c. It surprises me how long it takes for the water to appear out the exhaust on relaunch.. I also had a problem starting after relaunch on one occasion and discovered that I had carelessly replaced the battery in such a manner as to strain the stop cable. Once this was eased she started and ran fine. My experience with the md11c has been very positive and she continues to be very reliable if a little white smokey.

 

[Swanrad2]

So what happened has happened elsewhere apparently so maybe worthwhile sharing. On reftitting the 'new' injector pump the wrack and throttle assembly appear to have become misaligned. They jammed. My careful wiggling until it freed damaged the wrack which caused a sudden spike in revs when we restarted it somehow. A kind of mini-runaway which because there was no water running through and if we hadn't been able to kill the engine might have killed the engine permanently.

I still don't know for sure how we stopped the engine - I had three separate plans when the revs spiked and between me and my mate threw all of them at the problem. Diesel tap off, injectors cracked at the pump rags pushed into the air intake. For some reason I forgot the decompressors though!

Scavenging one injector pump from two cost £100. Refurbing the original over £300! We will try attaching the thing again this weekend and won't stop until we test all of the bits and bobs back there! Also managed to refurbish/replace some seriously seized masthead sheaves so getting dangerously close to seaworthy again (only two months behind what I used to laughingly call a 'schedule').

I think the biggest lesson I have learned from the engine repair process is bite the bullet and if you can take it out of the boat early on do so. This (hopefully) last bit would have been easy if the engine was on a bench and I probably wouldn't have misaligned the pump anyway.

 

[DownWest]

Had something similar on a Coventry diesel. The throttle arm was very stiff and the revs were too fast. Found that the rack was jammed. Carefull amount of persuasion managed to free it. I suspect it was two of the four jerk pumps sticking. We removed the cover on the gouvenor and levered the rack control back and forth. Once it was moving we fired up again and it suddenly co-operated. Be aware that the throttle is not directly connected to the injectors on a diesel. It tells the govenor what speed you want, then the gov operates the injection pumps to obtain that rpm. Hence the wide open start up and black smoke, until it reaches the set rpm.

 

[Bilgediver]

So what happened has happened elsewhere apparently so maybe worthwhile sharing.

To avoid this problem ensure that the rack complete with the wee bobbin on the pin is exactly lined up so the bobbin will enter the fork on the operating lever. do not waggle the speed control till the pump is seated! If the bobbin is not in the fork then there is the risk of the engine being speeded up but not then slowed down!!!!

If like me one is large build then need to find a skinny friend for this who can lie over the engine and see exactly what is going on:encouragement:

 

[aquaplane]

A bit about the cold start button.
There is a version where you can pull a cable which rocks a lever which presses the button in.
Then there is one like mine where you have to remove the inspection hatch in the bottom of the cockpit and reach in to press the button in.
I have modified min with a bit of ¼" pipe so I can engage it remotely, it sticks up into the engine pannel moulding just below the temp gauge.
You have to have quite a lot of throttle on to get the cold start button to stop in, I put the lever at about 9 or 10 o'clock.

 

[Swanrad2]

A bit about the cold start button.
There is a version where you can pull a cable which rocks a lever which presses the button in.
Then there is one like mine where you have to remove the inspection hatch in the bottom of the cockpit and reach in to press the button in.
I have modified min with a bit of ¼" pipe so I can engage it remotely, it sticks up into the engine pannel moulding just below the temp gauge.
You have to have quite a lot of throttle on to get the cold start button to stop in, I put the lever at about 9 or 10 o'clock.

Mine is the rockd lever type. Still not quite got my head around how that works. The engine stop and cold start weren't functioning properly either - I suspect because of the stuck injector wrack. We will find out!

 

[KellysEye]

>so from experience is spray/wiggle/spray likely to free the thing off

When our throttle control on our MD17C engine was stiff I oiled with machine oil it and it was fine with a bit of wiggling.

 

[Swanrad2]

>so from experience is spray/wiggle/spray likely to free the thing off

When our throttle control on our MD17C engine was stiff I oiled with machine oil it and it was fine with a bit of wiggling.

The lesson we learned is if you have replaced the injector pump - wiggle gently or you can damage the pump!

 

[Bilgediver]

The lesson we learned is if you have replaced the injector pump - wiggle gently or you can damage the pump!

No a matter of wiggling gently....More a matter of wiggling ACCURATELY with the cam lobes set to be out of the way! The pump then drops into position.
Mind you this can be a problem for folk like me when hanging upside down through the cockpit hatch but easier for skinnies who can lie along the top of the engine.

 

[Swanrad2]

No a matter of wiggling gently....More a matter of wiggling ACCURATELY with the cam lobes set to be out of the way! The pump then drops into position.
Mind you this can be a problem for folk like me when hanging upside down through the cockpit hatch but easier for skinnies who can lie along the top of the engine.

Ahhhh - so we put the pump on, all was well. We started the engine and it rotated the cam. We stopped the engine the cams were in a different position and the wiggle bent he rack (it just dawned in me I have been spelling rack wrong as well)

 

[Bilgediver]

Ahhhh - so we put the pump on, all was well. We started the engine and it rotated the cam. We stopped the engine the cams were in a different position and the wiggle bent he rack (it just dawned in me I have been spelling rack wrong as well)

Are those your words or those of an (engineer)

The Rack is the cyindrical bit of steel which slides back and for in the body of the fuel pump. It is hardened and tempered has teeth machined on one side and a 5 mm pin on the other onto which you slip a brass nipple. No way can you bend the rack as it is almost fully supported by the pump body.

The nipple in the rack pin has to be positioned correctly and then the pump lowered down so it engages in the fork on the speed lever. It sounds like you got the nipple misplaced. It could either have gone to one side of the fork so allowed the speed lever to put fuel on but not take the fuel off or the nipple was horizontal and not vertical and by forcing the pump into place the speed lever was jammed and bent as in this position the nipple could not enter the fork on the speed lever. Hence my wording the pump should be LOWERED INTO PLACE. ie not tightned down with the nuts. IE if the flanges don t meet then find out why. This is what you must beware of in the future. The twiddling most certainly bent nothing

You can check all this is free after replacing the pump by removing the plate n the back of the engine and ensuring he fork and rack are correctly coupled.

The usual problem is folk dropping the nipple off the pin on the pump and losing it in the engine . This leads to poor speed control due to the large amount of free play in the pin to fork coupling.

Hope you are all sorted out and he engine is running as sweetly as ever.