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Vehicle Problem Record
When you start noticing things different with your car its always a good idea to list down what its doing different,when it does it etc.By recording the events it will make it easier for your mechanic to identify probable causes...I have found that by using this checklist the dealer/mechanic has a better understanding of what you find and the chances are that they will not fob you off so easily! Vehicle Checklist
1. What is it doing? ______Noise ______Visual ______Smell ______Performance ______Handling 2. Where does it come from?
Inside car
______Left ______Center ______Right
______Front ______Rear ______Instrument Panel
______Seat ______Door ______Window
______Roof ______Floor ______Rear Seat Area
______Luggage/Boot
Outside car
______Left ______Right ______Under car
______Front ______Rear ______Under hood
3. When does it happen?
______When car is not moving and engine stopped
______When car is moving and mostly:
______During braking
______During change from acceleration to coasting
______When shifting from forward to reverse
______During turning
______At ___ mph
______On rough roads
______While accelerating (increasing load)
______While decelerating (coasting)
Mostly when using:
______Brakes ______Heater/air conditioning
______Steering wheel ______Rear window demister
______Starter ______Radio/power antenna
______Clutch ______Windshield wiper/washer
______Other
When the engine is:
______Idling ______Hot ______Cold
______Being started ______Warming up
4. Does it vary with:
______Car speed ______Engine speed ______Trunk load
______Engine load (acceleration)
5. How often does it happen?
______Always ______Comes and goes ______After ___ miles
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Engine Misfiring Diagnostics
Here is the procedure for isolating which one (or more) cylinders are causing a "misfire" or rough idle in any standard ignition driven system (not diesel). The first thing we have to do is to find out why is is misfiring - not necessarily ignition related, but it could be. Do a compression test so we can rule out bad stuff. Write down the compression readings for all the cylinders. If one (or more) is more than 15% lower that the highest, then there is a problem with either the valves or the piston/rings. I won't go into the procedures to isolate that problem here. Assuming it turns out OK, then we do a "power test" by grounding out one spark plug wire at a time while it's idling. Use a small thin screwdriver or something else that you can slip under the boot that covers the spark plug. Attach a grounding wire to the screwdriver and clip the other end onto a metal part of the engine. With the engine idling, slip the screwdriver under the spark plug boot to short out that plug and stop it from firing, and note the drop in RPM - do it for all 4/6/8 plugs. One of them (or more) will not affect the idle condition as much as the rest. That one will be the offending cylinder. Next, find a spark plug wire which is the same length as the offending cylinder but caused a significant drop in RPM, and swap wires. See if the problem follows the wire or stays with the cylinder. If it goes with the wire then it's time to replace the wire set. No sense in just replacing the bad one - do 'em all. If the problem stays with the cylinder then start looking for a fuel problem with that cylinder. Look for a vacuum leak around the intake manifold for that area of the engine. Check all the vacuum hoses for cracks and leaks. If it is a fuel injected system (Port Fuel Injection) then pull the injector and see if it is functioning. If it isn't squirting a fine mist then check the signal to the injector using a special injector tester. Repair or replace as necessary. Finally, if nothing else appears to be wrong try swapping the spark plugs form one cylinder to another and see if the problem follows the spark plug. If it does then replace all the plugs. Note the condition of the failed plug and from which cylinder it originated. This may be an indication of other engine problems like oil burning in that cylinder. |
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My Car Will Not Start!!
This section is still a bit haphazard,you have to hop about the page,and since I am useless at installing hyperlinks(lazy too) it would be best for you to print this section off and read....having said that,I do hope something here will point you in the right direction!! It doesn't take much for an engine to run. All it needs is air, fuel and spark, that's it. First thing is to narrow down the possibilities as much as possible. Are we dealing with a starting/charging system problem, or an ignition problem. Maybe it's a fuel problem, or a mechanical problem that is giving symptoms of one of the others... If we haven't been able to get any preliminary information from the owner, we should try to narrow in on the problem as quickly as possible. It's just a decision tree type of process that’s been developed over the years that I find works well for me. Try to start it: If the starter engages and spins the engine over and sounds like this then the engine is "cranking" just fine, but it just doesn't sound like it's even trying to start. This means that the battery, starter, and neutral safety switch or clutch safety switch are all working fine. We can now skip half of the trouble shooting process and go below to the bold print "check for spark".
If it spins unusually fast, like the sound below, (listen carefully, the difference is subtle, the first one sounds like it's getting some resistance from the engine, while the second one is just freewheeling), then take a deep breath,and head below to the bold printed "Timing Belt"
If it doesn't crank at all, check the battery, if the battery isn't dead and the connections are clean and tight, there is a problem with the starter circuit. Try again, if it still doesn't crank, or even click, there may be a problem with the ignition switch, starter solenoid, starter, neutral safety switch, or the clutch safety switch.
Check for spark- pull a spark plug wire loose from a spark plug and get an assistant to hold it while you crank the engine. If he yells and jumps back, a good spark is present. (Just kidding, this is probably not a good way to check for spark, a better way is to pull the wire off of the plug, stick a screwdriver into the end and, while holding the plastic handle, move the screwdriver so that the metal part is close to a piece of bare metal on the engine. Then get someone to crank the engine. If there is good spark you should see a spark jump from the driver to the metal. If not, try "no spark "below. It should be able to jump a gap of almost 1/4 inch.) the ignition system is probably OK, replace the wire and Check for fuel TO the engine.
What have you got? If what you've tried up to now hasn't gotten you back on the road, we're in trouble. What we look at next depends on what we are dealing with. Open the hood. Prop it open. Look around. Is your car fairly new? look for the emissions decal. It's almost always on the underside of the hood. It is a treasure trove of information. It will tell you the engine size, the fuel type, and often something about the engine control systems. There is even a little schematic diagram of where the little vacuum hoses go, and what the acronyms are for all those little gadgets that the vacuum hoses connect. Can't find it? Step back and take a good look at the engine. It's usually not too tough to figure out the path that the air takes to get into the engine, there will be an air cleaner assembly somewhere in it, probably near the inlet. There needs to be a large enough diameter path for the air to flow reasonably unrestricted to the engine. After the air leaves the air filter, but before it passes into the engine proper, it will pass through one of three things; a carburetor, a flow measuring device, or a throttle body. There may be a combination of two or more. There may be fuel injectors in the throttle body, air inlet, intake manifold, or right into the combustion chamber. You may have to remove part of the air filter to see some models. If you see a bizarre collection of strange links and levers and tiny hoses and adjusting screws all collected in the same place, chances are you have a carburettor. If the linkage is fairly simple, and the throttle plates are mounted in a housing that also contains a fuel injector or two then you are probably dealing with a TBI (throttle body injected) engine. If the engine seems to be covered with fuel injectors then you probably have some version of a Multi Point system.
No spark: OK, nobody said this was going to be easy... First thing we have to do is find the distributor. It should be pretty easy to find because it will be on the other end of the spark plug wires you disconnected to check for spark. Examine the plastic cap that the wires plug into. Locate the hold down screws or clips and figure out how to remove it, it should be 2 or 3 or 4 screws or clips. Remove the cap, look at the inside, look for moisture, gray powder, and carbon tracks. Examine the center contact. Look at the rotor, wiggle it a bit, is it loose? it should be a snug fit on the shaft. Reach down and turn the engine over slightly by hand, watch the rotor, does it turn when the engine does? It better. If not, go below to "no rotation."
No Rotation: The distributor rotor doesn't turn: Uh oh, this might be serious. Actually, it IS serious. The distributor needs to be indexed to the opening and closing of the valves and the up and down motion of the pistons. This is done by driving all three parts from a single chain or belt. Either the distributor is driven by a gear cast into the camshaft or by its own driveshaft driven by the timing belt. If your car has a timing belt, (most do these days, sigh...) you need to remove part of the cover to examine the belt to verify that it is in fact broken. NOTE: It is usually fairly easy to remove the first piece of the timing belt cover, but it is always a bitch to remove the last piece. Don't try to cut corners, once you have the first piece off, watch the belt and sprocket while someone cranks the engine. If the sprocket doesn't turn, you've got a "blown timing belt".
You Have a Carburetor, now what? If there is a single universally recognizable component of an automobile, it would have to be the carburetor. No other part approaches the complexity of the dozens of mechanical links, flaps, bellcranks and jets that all carburetors have. They look incredibly complicated. They look like they were designed by someone nasty. They have all kinds of little hoses and cables going to them. There are several adjustment screws visible. DON'T TOUCH ANYTHING!
Watch while someone presses the throttle pedal so you can identify the throttle linkage. Watch as they push it all the way to the floor, most carbs have a link that causes the choke to be forced partially open when this is done. Look for the choke butterfly, we are gonna have to make sure it opens and closes properly, and we're gonna have to prop it open if the engine is flooded.
Your carb may not look much like the one on the left, but you should be able to locate the throttle linkage and the choke valve on any carburetor you come across. If you can't, either I've failed, or you are really du... I mean I haven't communicated well enough.
There are really only two things that go wrong with carburetors. Hard to believe, right? All those bits and pieces, all those links, cams and screws, all those jets and rods, all those valves and. . . I guess you get it, The two things that go wrong with carbs are:
1. they deliver too much fuel or...
2. They don't deliver enough fuel
The two most common reasons they deliver too much fuel are; the choke sticks closed, and the needle valve sticks open. The two most common reasons they deliver too little fuel are; the choke sticks open, and the fuel level in the carb is too low. A stuck choke is pretty easy to spot, as is petrol overflowing out the top of the carburetor, but a low level of gas in the bowl is a bit harder.
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A Carburettor!
OK, you've determined that your carburettor equipped car is flooded, now what? well, you need to open the choke,( just hold it open with your fingers) then you need to hold the throttle linkeage all the way open. What these two things do is to open up the air passage as completely as possible, allowing the maximum amount of air to get to the engine. You need this air to dry up the raw petrol that is laying all over the inside of the manifold and cylinders. Now get someone to crank the engine. It should start after a few seconds and you'll need to fart around with the throttle a bit to keep it from dying until the idle smooths out. Put the air cleaner back on and get on with your life! 90% of all flooded carburetor engines will respond to this technique. ASSUMing of course that you haven't run the battery dead in your vain attempts to start it... |
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Shitzer!! I have Fuel Injection.....HELP!!!
Now what? Beats me, I'll think of something... On the left somewhere is a schematic of the Throttle body injection system found in many Chrysler cars. As you can see, it uses a number of input signals to determine the fuel needs of the engine and then uses the single throttle body mounted fuel injector to deliver it. It also uses some of those input signals to adjust the ignition timing and alternator charge rate. All electronic fuel injection systems work basically the same way. Once you understand which signals are used during which operating conditions you are well on the way to identifying the problem. Cold engines need a richer fuel/air mixture to run smoothly. Once the engine warms up, the mixture should get more lean. A carburetor has a choke, which closes off the air passage into the engine, which causes a rich mixture for cold operation. A FI system has a sensor that checks the engine temperature, and changes the programming of the fuel injector to richen the mixture that way. An engine with this cold engine option disabled will idle poorly, and stall at intersections, but will run fine once it warms up. Fuel system, step one: Is there petrol in the tank? Are you sure? Is it getting to the engine compartment? Are you sure? Most engines these days are fuel injected, with a fuel pump either inside the fuel tank, or between the tank and the engine. The power for this pump comes through a relay, and is supplied through a fuse. If you don't have fuel pressure in the engine compartment, check those first. Many engines have a "fuel rail" with a connection point for a fuel pressure gauge. If someone was to remove the safety cap, and press down slightly on the bicycle tube style valve pin inside, gasoline would spurt out with some considerable force if the fuel line was properly pressurized. This would of course be extremely dangerous if the gasoline was to ignite, and of course it could spray into someone's eyes and blind them. Don't ever encourage anyone to use this quick method for testing whether fuel is getting to the engine compartment. HEY, I said I was workin' on it, now relax...
Multi-Point systems, not a lot different from the simple system on the left. It's still a logic unit getting a lot of input from sensors and then controlling some fuel injectors to deliver the correct amount of fuel to the engine. Some of the components used in a multi point system are the fuel pump relay, the fuel injectors, throttle position sensor, oxygen sensor, atmospheric pressure sensor, knock sensor, EGR position sensor, etc. (The list is bloody endless!)
If your symptoms only appear in the morning when your engine is cold, you need to look at the sensors that tell the system how warm the coolant is, as well as the extra injectors some systems use for cold enrichment. If your problem seems to only happen at a certain throttle position maybe you should look at the throttle position sensor. Hey, this isn't rocket surgery...although it sounds like it!
Timing Belt? If your engine spins unusually fast when you try to start it, but it doesn't even cough or sputter, you've probably blown your timing belt. This is not a thing that you wanted to discover today. The timing belt is there to drive the camshaft, which opens and closes the valves. It also has the function of keeping the camshaft and crankshaft properly aligned with each other to establish the "valve timing" (the relationship between the opening and closing of the valves with the piston's up and down motion.) Valve timing is essential for the engine to run at all, as you have just discovered. When the camshaft stops turning, the valves freeze in whatever position they are in at the time, but the pistons keep going up and down as usual. The distributor stops turning, so the spark plugs stop firing.
The geometry of the camshaft causes it to stop in one of a small number of positions, equal to the number of cylinders the engine has, resulting in at least one valve at least partially open in almost every cylinder. This causes the compression to be low for all cylinders, which is what causes the engine to spin so fast when you're cranking it. Some engines, (called "interference" engines) are designed in such a way that when this happens, at least one valve is hit by a piston when it reaches the top of the stroke, which of course bends the valve and reduces the compression on that cylinder to zip. This means that the head must come off, the bent valves replaced, the timing belt replaced, sometimes the pistons are damaged and they must be replaced also, as you can calculate, it's much cheaper to replace the belt before it blows on these particular engines. This is often mentioned in the owners manual, in the maintenance section, you did read the maintenance section didn't you?
Inside the distributor cap: There are two main things we look for inside the distributor cap, one is moisture on the inside surface, which allows the spark to jump directly from the center contact to ground instead of going through the rotor and out to the spark plug wire and plug. The other main thing we are looking for is carbon tracking or damage to the rotor. Carbon tracks look like lines drawn on the inside surface of the cap with a pencil, they will either go from one contact to another or from a contact down the side of the cap to the bottom. Remove the rotor, sometimes this means loosening a screw or two that holds it in place, but usually you just pull it straight up. Look at the bottom surface, look for carbon tracking or any burnt or otherwise damaged areas. If in doubt, replace them, they are just about the cheapest parts you are ever likely to buy for your car.
Now, let's see now, where were we...
I'm confused, how about you?
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More Checking!!
Check for fuel- If the engine has a carburettor, the simplest way to check for fuel is to remove the air cleaner and look down the carburetor throat while moving the linkage. If you see (and smell) a small stream of gas squirting there is fuel getting to the carb. WARNING: Make sure that the key is OFF when you do this, as the fuel can ignite and cause a backfire to send a ball of flame straight up into your face. This can be disconcerting, and can cost you your eyebrows or your eyesight. Do Wear safety glasses.
Most cars these days are fuel injected, which makes it a lot tougher to test. Fuel injected engines come in at least three varieties, direct injected(rare, except for diesels, which we won't be dealing with in this site), throttle-body injected, and multi-port injected.
Direct injection engines have a mechanical fuel injection pump that is connected directly to the engine and has steel fuel lines going to fuel injectors at each cylinder. Most diesel engines are direct injected, but we won't be dealing with them here for a while. (Although I am thinking about it)
Throttle-body fuel injection: just uses a fuel injector that is mounted where the carburettor would be. It is the easiest to check, just remove the air cleaner and look at the injector(s) while cranking the engine. They spray a cone-shaped fine spray of fuel which is easy to see.
Multi-port fuel injection: uses fuel injectors at each cylinder, activated by wires which go to each injector. The car's computer determines when to fire each injector and for how long. This one is a bit tougher to test, has more parts to act up, and much more wiring to get screwed up. As you might guess, this one is also the most likely to act up.
Check the battery: Maybe her indoors just left the lights on and ran it down. Check the water, if it's low top it up, especially if any of the plates are exposed. Put it on the charger for a while if you can. Check the connections. Check them again, absolutely the most common place to find a problem is the connection between the battery post and the cables that go to the electrical system of the rest of the car. Corrosion happens between the metal end of the cable and the metal post of the battery, where the two metals touch, where you can't see without removing them. Brushing off the green crud growing around the connection isn't enough, you have to remove the cable, scrape the surfaces clean and smooth, and then reconnect and seal them to slow down the corrosion.
Check for fouled or flooded spark plugs: Remove a spark plug and examine the end that is normally in the engine. If it is at all wet, covered with black, gooey stuff, or caked with deposits, clean or replace it. (Spark plugs are relatively cheap, so they are hardly worth cleaning, replace them.) Make sure that you don't damage the plug wires when you pull them off the plugs,(pull the boot part of the wire, closest to the plug, not the wire itself, and twist the boot to break the bond between it and the plug.) and change one plug at a time, because the wires must go to the proper plug. And don't cross the threads when you re-install them, if you do, you are in trouble, think of lots of cash leaving your small pockets,get my drift huh!
Sourced from various websites and magazines,especially Aardvark Automotive
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I HAVE A CARBURETTOR.....HELP!
The first step in dealing with carburettors is ensuring that the engine and ignition system are in good order. This includes valve clearance, valve timing, compression, point gap, spark plug gap, ignition timing, and overall condition of engine and ignition components. Otherwise it is impossible to make correct settings and adjustments. Many alleged "carburettor problems" are really engine or ignition problems
Areas of concern are: mechanical condition (including cleanliness), fuel/air mixture, and air-flow balance (multi-carburettor only). As these overlap and affect each other, a "hit or miss" approach is self-defeating. Ask yourself what the carburettor needs, and how much work you are willing to do. Does it need minor adjustment, or is a full rebuild required? Determine what the symptoms of the problem are, determine the cause(s), and take appropriate remedial action. The following is a guide to the common Carburettor problems.
Poor Idle Quality:
Air leakage (check gaskets and vacuum fittings)
Throttles not synchronised (re-balance carbs and reset linkage) on dual carburettors
Air valve sticking (clean and reassemble)
Obstructed float chamber or diaphragm vent holes (ensure that air filter and gaskets are correctly fitted)
Incorrect fuel level (clean or replace needle valves and reset float height)
Metering needle wrong or incorrectly fitted (check needle number, and install to correct height)
Diaphragm incorrectly located or damaged (holes on bottom of piston should be in line with and face throttle shaft, replace damaged diaphragm)
Temperature compensator faulty (with engine and carburettor cold, compensator cone must be seated, but free to move off its seat)
Vacuum leak around throttle shaft (replace seals and/or shafts)
Hesitation or "Flat Spot":
In addition to the above, check:
Piston damper inoperative (ensure damper is filled to proper level with correct oil, check operation by raising piston, whereupon resistance should be felt)
Air valve spring missing or damaged
Ignition timing incorrect
Throttle linkage operation incorrect (readjust and check for correct operation)
Heavy Fuel Consumption:
In addition to all of the above, check for fuel leakage
Lack of Engine Braking
Faulty bypass valve (replace diaphragm or entire unit)
Throttles sticking open
Ignition retard inoperative (if separate retard unit is fitted to distributor, check the operation, if not, ensure that distributor returns from advanced position)
Lack of Engine Power:
Damaged air valve diaphragm
Piston damper torn will give symptom of not being able to rev over 2000 or similar rpm
Low fuel flow (check fuel pump output, needle valve and seat assemblies, and float height)
Mechanical condition is relatively easy to determine. Are the carburettors clean? Do the linkages and other moving parts move freely? Are all gaskets and O-rings sealing properly? Does everything look and feel right? There should be no fuel or vacuum leaks. Inside the carburettor, check the large air piston diaphragm .It should be free of holes or tears. The bypass valve diaphragm (when fitted) should be flexible and free from holes or rips; these often tend become burned and hardened. Floats must not have cracks or holes, and should not contain fuel. Floats should be set to the correct height (check your manual). Throttle shafts should not bind, nor should they "wobble".
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