FAQ: How to Troubleshoot, Repair & Maintain Hondas and Selected Other Vehicles
Asked Dec 4, 2006, 09:16 AM
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1. If a diesel smokes, under any conditions other than full throttle or high load, something is wrong. Generally, too much fuel is being injected. At idle, or normal operating conditions found in the midwest of the U.S. And Canada, diesels shouldn't smoke.
2. Check engine oil level--ensure it's filled to the top line and that the oil and filter have been recently changed. Since this often affects fuel pressure (Ford), begin by ensuring it's properly filled.
3. Black smoke is usually a signal that there's too much fuel, not enough air, or injector pump timing is off. One of the most common causes is an air inlet restriction. The cause may be a dirty air filter, a collapsed intake hose, or an exhaust restriction.
4. Check air filter--ensure it has been changed recently (every 5,000 miles).
5. Check fuel injectors. Leaking injectors create an overly rich air/fuel mixture and cause black smoke. Take the valve cover off and look at the exhaust part of the injector, when it is running. Each time the injector fires, you should see oil exhausting from it. If you see oil coming out, then the injector is good. When replacing a bad injector, take the glow plug out and crank the engine to get any oil out of the cylinder. If you don't, you could hydro-lock and bend a rod.
6. Check turbo for carbon build-up and bent turbine blades. This ties into exhaust restriction.
7. Purge fuel filter or fuel separator of water. Do this at least monthly--daily, if necessary. Water can be a big problem with diesels. Watch for and treat bio-organisms.
8. Look into a commercial diesel fuel additive, which is available at most large truck stops. Try and find one that is pure biodiesel, intended to be mixed in the tank at a B20 or less rate. Look for the words "naturally produced oil" or "biodiesel" on the side of the can listing ingredients. Properly mixed, it will reduce the amount of smoke an older, worn engine produces.
9. Once you isolate and fix the problem, use full-synthetic heavy duty diesel engine oil (HDDO). Installing a by-pass oil filter makes using top-quality synthetics very cost effective, when integrated with a used oil analysis (UOA) program. All engines run better on synthetics, particularly turbo diesels. Besides significantly improved engine life, turbo life, performance, and gas mileage, synthetics promote easier starting, by allowing increased cranking speed. This last factor is particularly important in cold weather. Synthetics are also easier on batteries and starter motors. Finally, many diesel engines smoke dramatically less with synthetics. Anyone who has a turbo diesel and doesn't use full-synthetic HDDO is asking for trouble.
4. Cavitation, SCA and Diesel Engine Cooling Systems
The presence of a few tiny bubbles, some so small that you need a microscope to see them, can destroy a diesel engine. Cavitation is a problem that has plagued diesel engine owners for years, which is the formation and collapse of air bubbles on the outside of the cylinder walls during combustion. It does not apply to dry-liner engines. Repeatedly, these air bubbles implode against the liner's surface. It erodes the cylinder liner, ultimately penetrating the combustion chamber and ruining the engine.
Cavitation is aggravated by vibration of the cylinder liner. Movement of the piston causes the liner to vibrate at a high frequency. When the liner vibrates, bubbles are formed in water passages next to the liner. These bubbles then implode against the cylinder liner. The implosion of the bubbles ultimately forms pinholes in the liner.
In elastic media, such as air and in most solids, there's a continuous transition as a sound wave is transmitted. In non-elastic media, such as water and in most liquids, there's continuous transition, as long as the amplitude or "loudness" of the sound wave is relatively low. As amplitude increases, however, the magnitude of the negative pressure in the areas of rarefaction (pockets of low pressure) becomes sufficient to cause the liquid to fracture, causing cavitation.
Cavitation bubbles are created at sites of low pressure, as the liquid fractures or tears, because of the negative pressure of sound waves in the liquid. As wave fronts pass, cavitation bubbles oscillate under the influence of positive pressure, eventually growing to an unstable size. Finally, the violent collapse of the cavitation bubbles results in implosions, causing shock waves to be radiated from the sites of the collapse. The collapse and implosion of many cavitation bubbles, throughout an ultrasonically activated liquid, results in an ultrasonic effect. Temperatures in excess of 10,000 degrees F., and pressures in excess of 10,000 psi, are generated as cavitation bubbles implode.
Effects on Engine
Air enters the system through leaks or through a faulty radiator cap. Leaks reduce cooling system pressure and increase the potential for bubbles to form in the coolant. These bubbles will eventually increase pitting. Water pump impellers and housings can be victims of cavitation, caused by low system pressure or by air trapped in the system. Cavitation can also damage radiators and heater cores.
Since cavitation cannot be completely prevented, Supplemental Coolant Additives (SCAs) are necessary to provide a continuous protective coating on the metal surfaces of the cooling system. This coating aides in controlling and limiting engine damage.
The most important way to control cavitation damage is to keep the cooling system clean by periodically flushing it. Using distilled water, combined with flushing agents, will scrub the system of impurities, scale, or other build-up, allowing for a "second chance" when refilling with a 50/50 mixture of auto maker approved antifreeze and distilled water.
When servicing the cooling system, always check for leaks or faulty pressure caps. These conditions can cause air leaks, reduce operating pressure, and allow bubbles to form.
Add 8 to 10 ounces of SCA every 15,000 miles, testing it with Fleetguard strips every other month. Completely drain and refill the cooling system with a 50/50 mixture of approved antifreeze and distilled water every 30,000 miles. Be sure to remove the hex-head drain plugs, located on each side of the engine block, after disconnecting the negative battery cable. This is a must on diesel engines. Cavitation must be taken very seriously.
14. How-to Remove and Install a Transmission Range Sensor (TRS)
The Neutral Safety Switch is part of the TRS.
1. Disconnect negative battery cable.
2. Place gear selector in Neutral (N).
3. Remove air cleaner and air cleaner outlet tube, if necessary.
4. Disconnect TRS electrical connector.
5. Remove manual control lever from transaxle.
6. Remove TRS retaining bolts (2).
7. Remove TRS.
1. Ensure gear selector is in Neutral (N).
2. Install TRS and loosely install both retaining bolts.
3. Align TRS slots using TRS Alignment Tool.
4. Tighten TRS retaining bolts 9 to 12 Nm (80 to 106 inch-lbs.) and remove tool.
5. Connect TRS electrical connector.
6. Install transaxle manual control lever--tighten 11 to 16 Nm (98 to 141 inch-lbs.).
7. Install air cleaner outlet tube and air cleaner.
8. Connect negative battery cable.
9. Check for proper operation with parking brake on. The engine should start only in Park (P) or Neutral (N).
Exhaust gases from a diesel engine should be colorless. Smoke of any color is a clue that it’s not running properly. Here’s what exhaust smoke tells you:
• Black smoke is a sign of engine overload, restricted air supply, or malfunctioning injector. For some reason, excess unburned fuel is being blown out the exhaust. Black smoke is usually a signal that there's too much fuel, not enough air, or injector pump timing is off. One of the most common causes of this condition is an air inlet restriction. The cause may be a dirty air filter, a collapsed intake hose, or an exhaust restriction.
Installing a power chip can cause engine overload (boost gauge maxing out), black smoke, and engine shut down. I usually recommend using the standard OEM chip. On a diesel engine, injecting more fuel will result in more power--up to a certain point. This is almost opposite of a gasoline engine, where adding fuel and richening the mixture excessively will kill performance and lower power. A diesel engine is totally different. As you add more fuel and richen the mixture, power output will continue to climb, until the point that there is so much fuel that much of it is unburned (or partially burned black smoke) and then the power increase will taper off. Before the power increase drops off dramatically, however, you'll be facing another limiting factor--exhaust gas temperature (EGT). Adding more fuel makes more power, but it also raises EGT. If you add too much fuel and exhaust gas temperatures get too hot, then you can seriously damage your engine. Hence, an important reason to only use full synthetic HDDO. Full synthetic HDDOs also help control or eliminate black smoke, in many situations, by allowing the engine to run much more efficiently, even when overloaded.
• White smoke is a sign of water vapor or fuel that has been atomized, but not burned. Water vapor may be present in the fuel, or water may be leaking into the cylinders from the cooling system. Also, air in the fuel can cause white smoke. White smoke usually occurs when there is not enough heat to burn the fuel. The unburned fuel particles go out the tailpipe and typically produce a rich fuel smell. It's not unusual to see white smoke in the exhaust, during cold weather, until the engine warms up. Bad glow plugs (burned out, coated with carbon, or not receiving proper start-up voltage) or a faulty glow plug control module can cause white smoke on engine start up. Low engine cranking speed may also produce white smoke. If white smoke is visible after the engine has warmed up, the engine may have one or more bad injectors, retarded injection timing, or worn injection pump. Low compression can also be a source of white smoke.
• Blue smoke forms when the engine’s lubricating oil is being burned, indicating worn piston rings, valve guides, or seals. Also, the oil can come from an air filter overfilled with oil or an overfilled crankcase.
Wax, naturally found in diesel fuel, begins to form crystals, as the temperature drops. The cloud point is the point at which crystals form. Eventually, crystals clog the fuel filter and starve the engine of fuel or prevent it from starting.
Traditionally, one solution is to use #1 diesel fuel, which is diesel fuel diluted with kerosene. There are several disadvantages with using #1 diesel fuel, despite its advantage in low-temperature operations. First, the energy content is about 95% of #2 diesel fuel, resulting in less horsepower and reduced fuel economy. Second, the kerosene used in #1 diesel fuel provides less lubrication for the fuel distributor and fuel pump, increasing the likelihood for wear.
There are products on the market, such as Amsoil Diesel Recovery, that dissolve the wax crystals that form when diesel fuel has surpassed its cloud point. It will liquify gelled diesel fuel and thaw frozen fuel filters. Since diesel fuel quality varies wildly from one filling station to another, low-quality fuel can have cloud points as high as 40 degrees F.
Check these type of products out. They can reduce the cold filter-plugging point (CFPP) by up to 34 degrees F, in ultra-low-sulfur diesel fuel (ULSD), and up to 17 degrees F, in biodiesel. They also lower the fuel's pour point. Emergency diesel fuel treatments may help you avoid a costly towing charge.
Steps to improve cold weather diesel starting:
1. Use the appropriate winter viscosity of full synthetic HDDO for your vehicle.
2. Add Amsoil Diesel Concentrate Plus Cold Flow Improver (DFC) to diesel fuel in the winter, prior to crystal formation. Use this product throughout the winter months, starting at 40 degrees F.
3. Add Amsoil Diesel Recovery Emergency Fuel Treatment (DRC) to diesel fuel, after crystal formation.
4. Install a engine block heater for temperatures below -25 degrees F.
5. Ensure both batteries are fully charged and the battery terminals and cable connections are clean. Apply dielectric grease.
12. How-to Perform Electronic Air Temperature Control (EATC) On-Board Diagnostic Tests on Many Fords and Mercurys
NOTE:Intermittent (run time) trouble codes will be deleted after 80 ignition cycles.
The Remote Climate Control (RCC) module is capable of displaying both self-test faults and intermittent (run time) faults on the Integrated Control Panel (ICP). To obtain these codes, perform the following EATC on-board diagnostics test:
. On-board diagnostics should be run in ambient temperatures between 50 and 90 degrees F. Record all Diagnostic Trouble Codes (DTCs) displayed during diagnostic test mode.
. Turn ignition switch to RUN position.
. Push both OFF and FLOOR buttons simultaneously; then, press AUTO within two seconds.
. The test may run as long as 30 seconds, while the display will show a dashed line in the center of the display window.
. After about 20 seconds, a DTC will appear in the display. The self-test is completed when 888 appears in the center of the climate control display window of the ICP.
. To exit the self-test and retain all intermittent DTCs, press the "-" (cooler) side of the TEMP button. The RCC module will exit the self-test and retain all intermittent DTCs.
. Always exit the self-test, before powering the system down (system turned off).
. Refer to a DTC Index for additional help. Here are several common self-test faults:
024--A/C Electronic Blend Door Actuator Failure
030--In-Car Temperature Sensor Short
031--In-Car Temperature Sensor Open
040--Ambient Temperature Sensor Short
041--Ambient Temperature Sensor Open
050--Sunload Sensor Short
. Some heating and air conditioning control problems are solved just by running the self-test.
1. Replacing platinum spark plugs with the exact ones (same brand and part no.) that came in the vehicle and ensuring they are properly gapped. If the vehicle came with single platinum plugs, changing them to double or quadruple platinum plugs can cause misfires, particularly if the gap is different. Therefore, I recommend using single platinum plugs and changing them every 50,000 miles. On FWD V-6 engines, be sure to change the rear plugs, despite the hassle.
2. Applying dielectric grease to the spark plug's porcelein and electrode.
3. Changing coils and coil packs, if changing spark plugs did not solve the problem. Bench testing coils is not reliable, since most break down under load (heat). Therefore, be sure to change coils and coil packs every 120,000 miles or 10 years, whichever comes first. Apply dielectric grease to terminals.
4. Replacing Ignition Control Module (ICM). These problematic components should be replaced every 120,000 miles or 10 years, whichever comes first. Bench testing ICMs is not reliable, since most break down under load.
5. Ensuring coil-on-plugs are squarely centered on the plug's electrode.
6. Changing spark plug wires every 80,000 miles. Regularly, wipe down plug wires with silicone spray, being very careful to keep it away from oxygen sensors.
7. Checking for intermittent codes that did not trigger the Check Engine Light.
8. Checking engine compression and looking for intake manifold leaks, in extreme cases.
9. The link below, provided by kitch428, covers a number of advanced techniques for diagnosing engine misfires:
30. Toyoto to Begin Requiring 0W-20 Synthetic Engine Oil
Driven by increasingly stringent emission and fuel economy standards, Toyota has informed its dealers that the company will begin requiring SAE 0W-20 synthetic engine oils in new Toyota, Scion and Lexus vehicles over the next several years. Other OEMs are expected to follow suit by 2011. Among the benefits cited by Toyota are enhanced protection at high and low temperatures, improved fuel economy and reduced engine deposits. In addition, Toyota is reportedly studying increasing oil drain interval recommendations to 10,000 miles.
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I replaced my distributor on 92 accord following you instructions. However, towards the end, it says that I need to read section C and D to precisely set idle speed and ignition timing. Can you tell where I can find those Sections? Thanks.
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