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governor problem?

Started by fabricator, December 24, 2011, 12:37:54 PM

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fabricator

Definitely towards the "give me more fuel" position.

Carlb

if the rack is moving in the more fuel direction either you have a fuel starvation problem or the ip pump problem.  I suspect its a fuel starvation problem.
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fabricator

Well today I put a new fuel filter on it and it had no effect, so I screwed around with pump timing, I really can't make heads or tails of the directions in the book, it refers to a mark on the flywheel rim that is supposed to show 18-20 degrees BTDC, there aint no such mark on these flywheels, anyway I set it where they seem to be trying to indicate and added a stronger governor spring and it is somewhat better, it only slows down maybe 50 rpms now, not right down to sounding like it's gonna quit.
I can't see how it could be a fuel starvation problem, I have semi clear 3/8" lines and a large spin on diesel filter and everything is solidly full of fuel, never any signs of bubbles, I have the type of clamps you pinch with straight jaw wire cutters so those connections are super tight.

dieselgman

We had a recent discussion of this issue on the LEF where a fellow was having sluggish governor response... after going through all the usual suspects I believe his problem was resolved when he found that the external linkage was actually bent out of its original shape a bit - causing the problem. This was after he went to the trouble of working on his fuel pump. We can offer a replacement on the pump easy enough, but maybe best to recheck that linkage. Governor bottom lever and governor upper lever should look like 90 degree bends. That upper lever in particular often gets bent to some other angle during shipping/handling.


dieselgman
Ford Powerstroke, Caterpillar 3304s, Cummins M11, Too many Listers to count.

fabricator

Oh I'm not givin up that easy, at this point I don't think it's the pump, right now I'm suspicious of one of my fuel line connections, I'm gonna straighten that out tomorrow and go from there, can somebody point me to some good pump timing instructions in English and given the fact that there are no timing marks on my flywheel.

dieselgman

Pretty good straightforward instructions are on LEF... unfortunately out of commission at the moment. You will have to locate and inscribe some timing marks on your flywheel. For starters you will need a pointer device of some sort, (I've seen them commonly bolted to the fuel pump), then you will need to find TDC on the compression/firing stroke. This will be the point at which the piston reaches its maximum height and is ready to descend again with both valves fully closed - cam lobes pointing down. You will need to mark this as a beginning reference point. Then depending on your specific flywheel diameter, you will measure back to find and mark the desired firing point around 20 degrees btdc. The rest can be done by-the-book for adjusting the fuel pump cam follower length until pump spill-point equals firing mark. Maybe the LEF will be back online shortly... if not I can pull up full details and post here when I get the chance.

dieselgman
Ford Powerstroke, Caterpillar 3304s, Cummins M11, Too many Listers to count.

fabricator

I've got a perfect spot for a pointer on my fuel filter bracket.

Ronmar

You will have to make your own timing marks.  First thing you do is find TDC.  Pull the injector out and slide a long rod down in thru the combustion chamber to rest on top of the piston.  Roll the flywheel slowly while feeling the rod rise to it's peak.  Compare the rod with the keyway to locate TDC as accurately as possible.  Make a mark on the wheel at that good pointer location.  I think I used the banjo bolt on the IP as my pointer.  Once you have TDC on the flywheel, use a cloth tape to measure the circumference of the flywheel.  divide that measurement by 360.  Multiply that number by 19 and measure clockwise that distance around the wheel from the TDC mark.  That is your spill timing mark. 

Spill timing is easy once you think about it.  The IP is gravity fed.  The fuel flows in thru the feeder port In the side of the IP cylinder.  As the IP piston rises, it blocks this port.  The point where the IP piston closes the fuel inlet port marks the start of the IP pump stroke and is the spill timing point.  The IP then has 19 degrees of flywheel rotation to compress the fuel to the pop pressure of the injector right around TDC.  There are 2 ways to find this spot accurately.

1.  Set the flywheel just before the TDC mark(toward the 19 degree BTDC mark) Since you already have the injector out, remove the high pressure pipe and the top fitting from the top of the IP.  Under that IP top fitting is a little plunger with a spring on top.  Remove the spring and replace just the top fitting.  That spring and plunger is a checkvalve that keeps fluid in the hardline while the IP piston is going down.  Without the spring, the fuel can flow thru the pump easier.  No fuel has flowed so far because with the flywheel between the 19 and TDC marks the IP inlet port is closed.  Roll the flywheel back toward the 19 mark and fuel may flow out the top depending on your fuel source pressure, but may not with the plunger still in there.  If it dosn't flow rock the flywheel back and forth across the 19 mark, oh make sure the fuel rack is in the full throttle position.  Rocking the flywheel back and forth from before 19 degrees and TDC will cause the IP to pump fuel up into the fitting eventually filling it.  At that point watch the fuel closely and with the flywheel before 19, slowly rotate the flywheel in the normal running direction till you just start to see the fuel begin to push up in the fitting top port. You can also remove the IP top fitting and watch the plunger valve move also.  That point is where the IP inlet port gets sealed and the IP just starts to push fuel.  That should occur at the 19 degree point.  If it does not, you need to adjust the IP plunger linkage to make it happen at that point.

2.  If when the spring over the plunger is removed fuel flows when the pump inlet port is open(before 19 degrees) or you can remove the plunger along with the spring to insure this happens.  Slowly rotate the flywheel backward toward the 19 degree BTDC point and at some point fuel will start to flow.  Slowly rotate the wheel in the running direction watching closely till the fuel just stops flowing.  Again, this just indicates that the IP inlet port is closed, and again, this should happen at the 19 degree BTDC mark on the flywheel. You can go back and forth a few times to confirm it, but only check the mark when rotating the flywheel in the normal running direction.

I like method one as it will only move fuel and lift the plunger when rotated in the normal running direction.
It is also not as messy, dosn't spill as much fuel.

Once the spill point is set, re-assemble the IP check and spring and install the rest of the plumbing and injector and purge the system and run it:) 

Since it is gravity fed, a restriction in the fuel path could inhibit the filling of the IP and cause issues without any sign of air in the lines...           
Ron
"It ain't broke till I Can't make parts for it"

fabricator

Now THAT is English, spill timing for dummies  :D Thanks a ton Ronmar.


fabricator

Ok guys I messed with the roid all day today, found TDC made a mark and a pointer then I found 19 degrees BTDC and made a nice mark. The up shot to this story is the fuel will never shut off no matter that I do, I can adjust the tappet bolt from not touching the pump to the tappet so high I can't roll the engine over because the pump piston is hitting the top of the pump and the fuel never shuts off.
I took the pump apart and checked everything inside, the timing marks on the rack and the gear are lined up, the curious thing is when looking into the fuel outlet hole and moving the rack there is never a spot where the passages are all covered or closed.
I followed Ronmars instructions so many times I can do it blindfolded, so, now what?

dieselgman

Important... are you certain you are on the correct stroke? Try spinning it through several complete cycles and try again... fuel must shut off at some point unless the plunger is stuck or incorrectly installed/machined. Stranger things have happened!

I can send you another pump or pump parts to help if you want to experiment with it that way.

dieselgman
Ford Powerstroke, Caterpillar 3304s, Cummins M11, Too many Listers to count.

fabricator

Well, there is only one stroke where the piston is at TDC and both valves are closed, I'll do some more checking tomorrow and let you know what happens.

XYZER

I have had the same problem. I have had the same symptom while timing the spill......then it magically fixed itself after much diesel on the floor. I think it was the rag I had tied around the pump to soak up the excess. Make sure the rack is open...? Maybe not .....I do feel your pain!
Vidhata 6/1, Power Solutions 6/1, Kubota Z482

fabricator

Well, I figured out a way to do away with the mess, I stuck a piece of clear vinyl tube on the fitting on top of the pump so you can see the fuel flowing, then I made a little bushing to put in the top of the tube to accept a smaller piece of tube that drains into a jar.