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Volvo MD11C timing

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enviroguy

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"Hi all,
I'm going to att

"Hi all,
I'm going to attempt to adjust the fuel injection timing on my Volvo MD11C engine (there is black smoke - injectors have been rebuilt recently) The manual says "Measure the distance from the timing gear cover to the base circle of the pump cam [the cam should be turned toward the crankshaft] Dimension should be 82.8 mm +/- .2 mm." I am not near the engine right now, but agonizing about these instructions - can anybody explain that more clearly? Also, once you have the injector pump out, you shouldn't turn the engine, should you?
Dennis"
 
"I Think, (I emphasise I t

"I Think, (I emphasise I think because that's one part of the MD11 we never had to touch) that it does mean that you do have to rotate the engine so that the measurement is made to the heel of the cam ie with the lobe that operates the pump turned away and pointing towards the crankshaft I assume you only bother to do the measurement to one of the cams. I don't see that you can do it without tuning the engine to get the camshaft in the correct orientation

You say you have had the injectors rebuilt but are you sure the injection pumps are OK. If they are getting clapped out so that the delivery pressure is low won't that result in poor atomisation and hence a tendency to produce smoke"
 
"Thanks very much,Vic. I had a

"Thanks very much,Vic. I had already taken my injector pump (Bosch) into a great service place - the guy there said there was a bit of corrosion in the bottom of the pistons (there are 2 - it's a 2 cyl. diesel)and a bit of wear on the rollers - which will be replaced.
He suggested the timing setup be done by measuring from the top of the engine where the pump is mounted, down to the "base circle" of the cam. I guess it will be obvious what that refers to when I look at it this weekend.
By the way, my black smoke diminishes as the engine temperature goes up, so I may have a valve problem or ring problem - in other words I may be looking in the wrong place; however, I didn't have this problem at the end of last season before I had the injectors out for servicing (strange) I already "cross-examined" the diesel service guys and they documented that the injector tips do have the specified Volvo MD11 specs as to orifice etc.
All very complicated!
Dennis"
 
"I assumed from the way you wo

"I assumed from the way you worded your question that you had the workshop maual. if you dont then

THERE IS ONE HERE

OK for the owners manual or do you want a link to that?"
 
"Thanks again, Vic. I have the

"Thanks again, Vic. I have the shop manual and the owner's service manual (if that's the one that covers inhibiting, bleeding the fuel system, etc.) There may be another one I don't know about.
Cheers
Dennis"
 
"Well, I had an interesting we

"Well, I had an interesting weekend re-installing my injector pump and figuring out the governor control settings and timing. The timing is controlled by .008" thick gaskets/shims, using more or less as required based on a measurement from the engine block at the pump mounting area to the base circle of the cam. I was able to rotate the engine to get the base circle uppermost, and use my depth gauge to ascertain the depth and compare to the manual. It turns out the depth is a bit too great, indicating that zero gasket/shims are required, and possibly bigger rollers needed on the injector pump. I installed it nevertheless.
I initially set the "throw" of the control rod to what the manual indicated, which is done by loosening a locknut and turning a small slot head threaded rod. After assembling all, I ran the engine and it was relatively lacking in power. I dismantled all and increased the governor setting to better effect.
There were various periods over the weekend travelling when the engine was running OK, but it never seemed up to full power, sometimes ran quite a bit unevenly, lost a few 100 rpms gradually and had a fair amount of black smoke on startup.
I am now suspicious that the FUEL QUALITY is suspect. This fuel sat in the tank over winter without additives, and it's now nearly a year since a portion of that fuel was added. I think I'll pump it out and clean the tank bottom and see if this helps. Meantime, I've learned a lot about diesel fuel injection!
Any comments or further suggestions most welcome!
Dennis"
 
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