I have a 1995 Honda Civic EX and lately i have been having some problems with the engine. Usually this only happens on damp and cold days but it has happened on maybe once in the summer. Ok its kind of hard to esplain but when i try to start the engine it almost seems as if the car is like misfiring. The engine will shake very violently and actually causes the whole car to vibrate with it. Its like one of the cylinders isnt getting a spark of something. I do have several engine modifcations like a high pressure fuel rail, AEM cold air in take, MSD ignition systems, I think its also has a Crane Cams Distributor on it too. i bought the car with all the mods on it and this problem wasnt really a problem in the past. It did it maybe only one time last winter but this its becoming pretty routine. ONe other thing that it will do is once it finally gets going it runs very rough until i rev it up above 5500 rpm. After that i everything looks fine. I have gotten several opinions and most people tell me to check the spark plugs and wires for any damage and stuff. Is that what might be causing this eractic behavior? Please let me know of any ideas anyone might have, it would be appreicated. Thanks

 

First you want to check that you actually do have a misfire. If the car is OBDII (1996+ car in U.S.) you can hook up a scan tool to the car and get the code. If there is a misfire, there will be a check engine light and a DTC. THe DTC will also tell you what cylinder(s) are misfiring. If you have determined that there is a misfire, the next thing to check is what is causing the misfire. THe misfire can be caused by lack of fuel, spark, compression or air. To check the fuel, spary WD-40 (or fuel) through the vacuum fiting on the valve cover or throttle body will also work. If the misfire goes away, then the problem is that a cylinder (or cylinders) is not getting fuel. To check the compression run a comp test. Check the air by taking out the vacuum hose and checking with a scan tool if the Air/Fuel ratio is geting leaner (you can also do the same with the fuel test). Hope that helps.

 

Ok well, i dont have a check engine light or anything like that. thats why i am so confused about it. maybe its not misfiring i dont know, it just what it feels like. Would a crack in a plug wire or some something electrical causing it to arc be able to cause it to have problems starting.

 

What year is the car? And yes if the spark plug wire was damaged in any way, it would cause a misfire because teh spark would not reach the spark plug, instead it would arc to the nearest metal object.

 

it a 95 civic Ex. Well if it was arcing wouldnt it be arcing all the time and not just when it starting, although, maybe it is and i just dont know it. Someone actually told me a way to figure it out if it is arcing would be to take spray bottle and spray the electrical things to see if it will arc and then i would know where the problem is. Would that work to figure out if thats the problem and would that cause damage to it?

 

If the spark plug wires have gone bad and are arcing, then yes, if you spray the car with water it will begin to misfire. And if the wires are arcing, they might not arc all the time, they could just arc some of the time.

 

Ok well i havent really gotten around to checking the plugs but i did notice on other that was out of whack. I have a high pressure AEM fuel rail on the car with a pressure gauge as well. I never really thought of it before but it was running at like 40 to 50 psi and a couple of days ago it was running over 80 psi. Now it is actually off the scale. If there is anyone who can tell why that is so high let me know. Thanks