Originally Posted by FlyingCloud1937
Also the injector pump timing is critical, and can only be set properly by bringing the #1 cylinder up to top dead center on the compression stroke. Then drop the valve spring on the #1 intake vale, let it sit on the top of the piston, Then set up a dial indicator and move the engine by hand to get the reading to top dead cent by measuring the top of the valve stem. Then counter rotate the engine back, about 1/4 turn, look up in the work shop manual degrees BTDC set the pump timing, rotate the engine forward until the dial indicator moves to the required point, the adjust the injector pump to the timing marks.
This wont give you an accurate crankshaft position as the piston doesn't move enough when close to tdc to get an accurate reading and you have no way of actually measuring the angle.
There are possibly timing marks on the flywheel or crankshaft pulley that will indicate tdc and / or the injection point or a range of degree marks. If there are then check these are in the right place when No. 1 is at tdc and use these. It is possible that the flywheel has been mounted wrong so the marks may line up on a different cylinder tdc or not at all. Some engines also have a plug
in the side of the block that can be removed and a pin inserted which will locate in a hole in the crankshaft when it is in the correct position.
If neither are the case then you will need to find tdc manually.
This is the method we always used when building engines where the timing marks were not reliable.
Firstly, make sure everything around the area is spotlessly clean. You will have parts of the fuel sustem open and any dirt can cause major problems.
You need a large diameter circular protractor and a dial gauge. All of the injectors should be removed so that the engine can be turned easily.
The protractor is mounted on the flywheel or crankshaft pulley, depending on what is accessible. The angle is not important, as long as it is centered on the crankshaft and doesn't move on it's own.
A pointer is mounted on the engine block somewhere and points at the degree marks on the protractor.
Turn the engine until No 1 piston is near tdc. Lloyds method of using one of the valves with the spring removed will work well but the rocker gear
will need to be removed and it can sometimes be difficult to remove the valve spring while the head is in place. If the dial gauge has a long extension that will reach down the injector hole and touch the top of the piston then that would be an easier method. You need to make sure that the dial gauge plunger does not jam as the piston moves up and down.
If using the valve then something needs to be wrapped around the stem to stop the valve dropping down the guide and into the cylinder if the engine is turned too far. An o-ring in he collet groove works well or a piece of tape wrapped around the stem after the oil has been cleaned off. if the valve does drop into the cylinder then the cylinder head will most likely need to be removed to retrieve it.
Once it is set up, turn the engine back and fourth over tdc and watch the dial gauge. set it somewhere close to the highest reading on the gauge. Lift
the gauge pin a little to make sure it is not at the end of it's travel. Most dial gauges travel about 1/2" or 10mm and it will be extending as the piston moves away from tdc. Set the gauge so that it can move out at least 5/16" or 8mm from where it is at tdc.
Turn the crankshaft backwards until the dial gauge is at or near the end of its travel.
Carefully turn the crankshaft forward towards tdc until the dial gauge reads about 1/4" (6mm) from the tdc reading. At this point, note the readings on dial gauge and on the protractor.
Carefully turn the crankshaft forward and past tdc until the dial gauge reads the same value as it did before tdc. Note the protractor reading.
True tdc will be the halfway point between both readings.
Check 2 or 3 times and make sure you get the same reading each time. Always turn the engine back past the start point and take both readings when turning in the same direction. When you have an accurate tdc angle, set the crankshaft at that point and permanently mark it for future reference with a hacksaw blade or center punch mark on the crank pulley or flywheel and a corresponding mark on the engine block or timing cover.
Once you have tdc then refer to the engine service
manual for the injector timing angle and set the crankshaft to that angle on the protractor from the tdc angle. Mark this position as well.
Spill timing the injector pump is the most accurate method but if the injector pump has timing marks that can be trusted then you should be able to align the pum to these and that will be all that is needed to get the engine running reasonably well. If there is any doubt in the marks or there are none then the pump will need to be spill timed.
Most good engine service manuals
or injector pump service manuals
should have instructions for spill timing and the method may differ between different types of pumps. It involves removing the injector pipe for No 1 cylinder and fitting a short pipe with the injector end open and angled so it will drip. An old injector pipe with the end cut at 45 deg and bent so that the end points slightly downwards works well. Place a container under the pipe to catch the fuel.
Most injector pumps will have a delivery
valve in the fitting that the injector pipe fits to. This is used to keep pressure in the injector pipe when the engine is running so that as soon as the pump starts delivering, the injector starts delivery
immediately. This valve needs to be removed to do the test. Remove the pipe fitting and remove the valve and spring and refit
the pipe fitting.
Inline pumps have a plunger that moves up and down in a barrel in the side of the barrel, is a port that is uncovered when the plunger is at the bottom of it travel. The lift
pump is used to provide enough pressure to fill the barrel above the plunger. When the delivery valve is removed, fuel will flow freely from the pipe.
When spill timing, the pump is moved until the fuel is just dripping out of the pipe at about 1 drip every 5 - 10 seconds. When the pump is just before the injection point, fuel will run freely from the pipe and when it is after the injection point there will be no fuel running out of the pipe. The correct position is just as the plunger covers the port in the barrel and this is the point that delivery to the injector is started. Depending on the lift pump, it may need to be operated continuously to keep the fuel flowing. If the delivery valve cannot be removed then this will definitely be the case or an electric pump
will need to be used.
With the crankshaft at the injection angle, loosen the pump mounting bolts until the pump housing can just be rotated. If it is too loose then it will be difficult to get the position accurately. It is better to have the pump firm and tap it to move it a little at a time.
Rotate the pump housing in the direction that the pump shaft rotates until fuel is flowing out of the pipe. Rotate the pump back the other way a little at a time until the flow turns into drips and there is 1 drip every 5 - 10 seconds. At this point, tighten the pump mounting bolts. If the rate of the drips changes then the pump has moved as the bolts are tightened. You will need to make very small adjustments and tighten each time until the drip rate is correct when the pump is tight.
As a final check, turn the crankshaft backwards a few degrees until the fuel is flowing from the pipe and then turn it forward until the fule is dripping at the correct rate. At this point, the crankshaft timing marks set before or the protractor pointer should line up with the correct angle for injection. Again, check 2 or 3 times.
If possible, mark the pump shaft in relation to the pump body. This way, if the pump ever needs to be removed, it can be refitted reasonably accurately.
Remove the spill pipe, refit
the delivery valve and spring, tightening the valve housing to the correct torque listed in the service manual. Refit the injectors and pipes, again, referring to the service manual for torque settings and if the valve spring was removed, refit this and refit the pushrods or rockers, which ever was removed to access the valves. Check the valve clearances if necessary.