Why will my 94 civic not start?

94 civic cranks, wont start?

• Hello. Yesterday my gf was on her way to work, and she came back inside and told me her car wouldn't start(never had problems before). So I went outside and tried it myself. It would crank and turn over just fine. Just wouldn't start up. The battery is fine, the spark plugs, dist. and wires are fine, and I checked to see if the fuel pump was running, which it is. No check engine light (though i'm not sure if it only comes on when the engine is running). What on earth could it possibly be? Btw, its a 94 civic ex vtec. Now I have access to alldata and I read up about the main relay, which is what my friend who works on hondas keeps telling me, that this is usually the cause. But alldata says the main relay performs 2 functions, "Contains two individual relays. One relay is energized whenever the ignition is on, and it supplies the battery voltage to the ECM, power to the injectors, and power to the second relay. The second relay is energized for 2 seconds when the ignition is switched on before starting, and when the engine is running, to supply power to the fuel pump." So, if he relay was bad, would I still be able to hear the fuel pump turn on for two seconds when i turn the key over? Thats whats I dont get...if the relay is what makes the fuel pump run for that first 2 seconds, then how can it be broken if I for sure heard the fuel pump running, or am I wrong about the relay and how it works?

• Answer:

  Forget about the main relay and stop jumping to conclusions. Reading this it sounds like you have some mechanical skills... You need to actually check for spark and fuel. Visually it can all look fine but at that critical point when it all comes together in the cylinders it may not be fine. First, check the engine ground. It should have a clean and strong contact to the body. It also doesn't hurt to go over the appropriate fuses at this time. Second, check your spark. Disable the fuel system. Pull out a spark plug and attach it to it's spark plug wire. Ground the plugs threads somewhere on the block, hold it by the plug wire's insulation. Have a partner crank the engine over, you are looking for a light blue/white spark jumping across the plug. If there is no spark: The ignition coil, igniter, distributor cap or rotor may be at fault. Third, check for fuel. Pull all the spark plugs out and disable the ignition system. Have a partner crank the engine over a couple times, smell the cylinders. You'll know right away if there is fuel or not. You can also use a noid light on them to make sure they are clicking on/off. If no fuel: Fuel filter may be clogged, fuel pump may not be able to supply adequate fuel (you'll hear it running, so listening for it doesn't always mean it is good), your fuel pressure regulator may be bad, injectors may not be pulsing on/off. Fourth, if you have spark and fuel. Check your timing. The car is old and the timing belt probably is too. It may have jumped a couple teeth causing the car to not start. If this is the case, replace the timing belt and the timing belt tensioner. http://img707.imageshack.us/img707/6219/capturebeltinstalation1.jpg http://img842.imageshack.us/img842/352/capturebeltinstalation2.jpg Since you have access to AllData, that will probably have better directions for checking the timing than those links. Fifth, if it's still not starting and your getting spark, fuel, and your timing marks are all good. Do a compression test and/or a leak down test. This will tell you if there is a problem with the cylinders building compression. If there is a compression problem the engine will have to be torn down and inspected. Sixth, if you have spark, fuel, compression, and all the timing marks are good. Then it may in fact be a problem with the main relay or ECU.