Ok, I'm going to take a few minutes and give some of you a breakdown of basic diagnostics. I don't answer "I having a problem with my car please help me...." threads because most of you don't even have enough info to even get an intelligent response, and usually the answers are worse than the question.
A car needs Four things to run.
Fuel, Compression, Spark, Timing.
To break down properly, a car needs PROPER Fuel, PROPER Compression, PROPER Spark, and PROPER Timing.
The below is considering the car is cranking over properly and Battery is at FULL CHARGE.
Lets start with...
So your car doesn't start, did you check spark??? How to check spark.
#1. Get a spark tester (very cheap).
#2. Use a spark plug. Take a spark plug, plug it into the wire. Use a pair of INSULATED pliers (the kind with the rubber handles), and hold the spark plug (steel part, base or threads) against a ground on the engine (steel bracket or something steel). So while holding the rubber part of the pliers, holding the plug, and it's touching metal to metal, have someone turn the vehicle over. Does it spark???
A. No, my car does not have spark.
1. Check to make sure the timing belt is turning the cam. (Can be done by removing the top cover, or simply by taking the oil cap off and watching to see if the cam is turning when someone turns your car over).
2. Check grounds.
3. Pull diagrams and start to check wiring with multimeter. The diagrams change from car to car. This step isnít for everyone, but is what to do to properly find the problem.
B. If you have FULL Battery Voltage, Cam is Turning, Grounds are Good. Then check wiring. Most likely cause is the Coil/Igniter. Other causes could be cam/crank sensors, wiring, etc etc etc. Hondaís do have a Coil issue, itís pattern failures usually seen at least once during the life of the car.
If it DOES have Spark, what color is it?
A. Bright Blue/White = Good spark.
B. Red/Orange/Yellow = not strong spark
Note: Please understand. Weak spark will STILL NOT fire the car off. Also understand that when using aftermarket or even ďPerformanceĒ coils, you are creating another variable. Honda Ignition systems have been proven to handle high HP applications. If you replace your coil with a new one that is NOT a Honda Part, donít keep asking the same questions until you use a NEW Honda part. Aftermarket parts are VERY unreliable, same goes for unkown used.
This goes for MOST Japanese cars. Ask Dealer Technicians. They will tell you how aftermarket parts greatly effect performance, even aftermarket plug wires can keep it from not starting, yes, itís true.
Note: Another thing you can do if you think your Distributor doesn't have any power is check all the fuses.
You can do this with a test light. Turn your car all the way ON, but don't crank it over, right before crank. Now make sure your test light has a GOOD ground, and touch each side of each fuse (two sides per fuse). It should light up on both sides, if not, it's blown.
Get a compression tester, they are not that expensive. Make sure you lube well before threading into the cylinder (spark plug hole), and don't TORQUE the daylights out of it, a LIGHT snug fit will fulfill the purpose.
Read compression tester instructions, or for basics, just test each hole. Install tester, and have someone turn over (AFTER unpluging distributor/ignition fuse (don't want it to start)). Let it "bump" the tester 3 times. Take the last reading from all cylinders, compare. Usually honda wants the variation between cylinders to be within 28psi or so. In other words, they should be close across the board.
If they are more than 28psi different, then diag further, it could be a problem with head gasket, timing belt, bent valves, bad compression rings, etc etc etc.
You can buy a fuel pressure tester, just like a compression tester. Check fuel pressure to spec. of your car. In general, I've seen very little fuel problems from Honda's. Personally, this would be the last thing I'd check on a Honda.
However, if you don't have a tester, check all the other first, if you think your not getting fuel, you can do it a "ghetto" way
You can take out the plugs, look inside the whole with a light and have someone turn over. You should see fuel spray or smell fuel strongly. Careful with fire hazards.
Note: Hondaís are also notorious for having bad ďMain RelaysĒ. Search and you can read up on this. This will allow you to have good spark, but will cut off the injectors from firing fuel. Itís a very easy and inexpensive fix. Usually located in under the driver side dash, close t tohe kick panal.
Note #2: Too MUCH fuel will also cause a car not to start. If you have a chipped ECU, or if your Coolant Temp. Sensor (tells computer the coolant temp and adjust fuel accordingly) is bad for example, it can cause the injectors to fire too much fuel and flood the engine. There are other factors that can cause this as well.
Note #3: Vacuum leaks can cause Too MUCH air. The mixture has to be just right for your car to run. If a vacuum line is open or broke, it may be hard for your car to start.
If others check out well, check your timing, OR if COMPRESSION is off, CHECK YOUR TIMING. There are two kinds of TIMING to check. IGNITION TIMING and VALVE TIMING.
Check your valve timing by taking the top cover off of the timing belt and check the belt/cam/crank marks and see if lines up like is supposed to according to the manual.
Check your ignition timing after the Valve Timing has been confirmed to be ok. You will need to use a timing light and research what you have to plug/unplug to get the proper reading. Checking your ignition timing is more for when you have it running. But you can still see if itís somewhat close with a timing light by just cranking.
A few IMPORTANT notes:
First, make sure your car is in good running order. Honda's are very picky when it comes to tune up parts. MAKE SURE you have good (or better NEW) NGK plugs (proper plugs for car) installed. Next make sure you use a Honda Cap and Rotor AND Ignition Wires. Sure others work, but have seen many issues because of the car simple not working with aftermarket parts. Do things right and buy OEM.
Second, buy some simple tools, spark tester, timing light, compression tester, coolant pressure tester, etc.
Third, if you have no idea what your doing DON'T ask the local parts jocky whats wrong, they are in parts for a reason.
Donít be afraid to pay 50-100 or watever it cost to have a GOOOOOOOD Independent shop Diagnose it for you. You will probably spend less in the end compared to throwing parts at your car and trying things and making it worse for a professional to figure it out. WARNING: You screw stuff up, it will cost more for you to have a true Technician figure it out.
Any questions regarding the above, or clarity, let me know, this is just a breif overveiw of the basics.
Modified by juevi at 6:52 PM 5/23/2007