First of all, what is a diesel engine?
A diesel engine (also known as a compression-ignition engine) is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber.
Info from: http://en.wikipedia.org/wiki/Diesel_engine
The following from Youtube shows a diesel engine
Who invented the diesel engine and when?
A little history of the inventor:
Rudolf Diesel, of German ethnicity, was born in 1858 in Paris. He was educated at Munich Polytechnic and after graduation, was employed as a refrigerator engineer, but more preferred engine design. In 1893 he described a slow-combustion engine that first compressed air thereby raising its temperature above the igniting-point of the fuel, then gradually introducing fuel while letting the mixture expand against resistance sufficiently to prevent an essential increase of temperature and pressure, then cutting off fuel and expanding without transfer of heat. His first successful engine was in 1897. His engine was the first to prove that fuel could be ignited solely with high compression.
Info from: http://en.wikipedia.org/wiki/Diesel_engine#History
Image from: http://en.wikipedia.org/wiki/File:Diesel_1883.jpg
What fuel pressure would you get from a diesel pump?
The pump develops great pressure—typically 15,000 psi (100 MPa) or more on newer systems. This is a good reason to take great care when working on diesel systems; escaping fuel at this sort of pressure can easily penetrate skin and clothes, and be injected into body tissues with medical consequences serious enough to warrant amputation. So, treat a diesel pump like a baby… with ALOT of care.
Info from: http://en.wikipedia.org/wiki/Injection_pump#Safety
This is a Diesel pump from a 12Cyl Diesel engine
Image from: http://en.wikipedia.org/wiki/File:12Zyl-Reiheneinspritzpumpe.jpg
How does the diesel pump work and why do we need to time the pump?
Traditionally, the pump is driven indirectly from the crankshaft by gears, chains or a toothed belt (often the timing belt) that also drives the camshaft on overhead-cam engines (OHC). The pump rotates at half crankshaft speed in a conventional four-stroke engine and its timing is such that the fuel is injected only very slightly before top dead centre on the next-in-line cylinder's compression stroke (The next cylinder to be fired).
Info from: http://en.wikipedia.org/wiki/Injection_pump
Why do we need to time the pump?
If the pump isn’t timed up properly to the engine, the engine would misfire, fire too early, or cause other major problems which would most possibly lead to the entire engine needing replacement.
How do you time the pump and with what equipment would you use?
FUEL INJECTION TIMING:
Unless major repair work is done on the engine, timing should not be required.
Basic tools required:
(A) - 10 MM Socket wrench
(B) - 13 MM Socket wrench
(C) - 17 MM Open end wrench
(D) - 12 MM Box end wrench
(E) - 27 MM Socket (1-1/16")
Engine firing order - Two cylinder - 1 - 2
(Front V belt end)
Three cylinder - 1 - 2 - 3
Four cylinder - 1 - 3 - 4 – 2
1. Remove fuel lines from injector pump fittings on injector pump (Tool C).
2. Pull decompression lever so that it will remain in the decompression position. No decompression lever on Model-i 2.
3. Open throttle fully.
4. Energize electric fuel pump and turn engine over with starter to ensure that fuel is coming out of each injector pump opening. Have clean rags around opening to soak up fuel.
5. Wipe off any fuel on injector pump body and the top of each injector opening.
6. Turn crankshaft over by hand, being careful not to damage spline on end of crankshaft. Engine rotation will be clockwise. STOP IMMEDIATELY at the first sign of fuel movement in the injector pump fuel fitting, for whichever injector pump is being checked. (No. 1 injector pump is the closest to the V-belt end of the engine).
7. Remove cover from flywheel timing mark inspection hold located inside of left engine mount (Tool B).
8. Check alignment of mark on flywheel with the timing pointer on the wall of the inspection hole. The 1-Fl mark on the flywheel represents fuel injection of No. 1 cylinder. 2-Fl represents No. 2 cylinder, etc.
9. If timing pointer and the flywheel marking 1-Fl is aligned then No. 1 cylinder is properly timed for fuel injection and should require no adjustment. The same will be true for No. 2, No. 3 and No. 4 cylinders if the above steps are followed.
10. In order to determine if timing is off, or if the injection pump is faulty, it is necessary to recheck the timing for each cylinder two or three times.
11 If there are variations in repeatability in the alignment of pointer and timing mark, a faulty fuel injector pump may be suspected.
12. If timing marks repeat to same location but are off 3/16" or more above or below the pointer, this indicates that the engine must be retimed.
If alignment of the timing mark is not within 3/16" above or below the pointer, the above steps must be taken to time the engine, If the timing is found to be satisfactory, then reconnect all fuel lines and fittings and tighten. The fuel system must be bled before the engine will operate properly. (See fuel bleeding instructions else where in this manual).
What is the purpose of a glow plug and how do you test the circuit?
A glowplug (alternately spelled as glow plug or glow-plug) is a heating device used to aid starting diesel engines. (Kind of like a choke, with out cutting off air supply) What happens when the ignition is turned on is, the power from the battery goes to the glowplugs turning them on which makes them heat up, heating up the cylinders to a high enough temperature so that the diesel being injected while the engine is cranking has a high chance to ignite.
Info from: http://en.wikipedia.org/wiki/Glowplug
Image from: http://en.wikipedia.org/wiki/File:Glow_plug.JPG
How do you check/test the circuit?
Testing glow plugs – the right way!
Step 1: The current input is tested at the main electrical connection to the glow plug using a ammeter clamp. If there are four glow plugs in the engine and each one requires 5 amperes, for example, the total current input has to be 20 amperes. If the measurement indicates a lower value, at least one of the glow plugs is defective. The current input varies from glow plug to glow plug. The data for all NGK glow plugs can be found at www.ngk.de/pro.
Step 2: If one glow plug is defective, we recommend replacing the entire set. If only one defective glow plug is replaced, each glow plug has to be tested separately. The resistance between the terminal nut and the metal housing is measured using an instrument that can indicate low test voltages.
Proceed as follows:
- Remove glow plug
- Clean threads of all rust, dirt, oil or paint
- Apply electrodes of the measuring device to the glow plug
- If the resistance value is around ∞ Ω, the glow plug is defective.
- If the resistance value is below 5 Ω, the glow plug is okay.
Info and image from: http://www.ngk-dpower.com/index.php?id=31&L=2
An easier and faster way to check if a glow plug is working is: simply remove the plug and attach power leads from the battery to the correct parts of the plug. (Positive to terminal and earth to shell) If the tip glows within 20 seconds, the glow plug works. If the tip doesn’t glow within 20 or more seconds, the glow plug is dead and you’ll need to get a new one.
Info from watching Rob checking glow plugs the EASY way.
Great work Alex.
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