How Can I detect an engine misfire?

Question

If I don't have a "Check Engine" illuminate nor nortice anything rough, how can I detect an engine misfire or cylinder misfire, whichever way they call it..

Answer 1

The "Check Engine" light will only illuminate for a misfire on cars 1996 and newer. If there is a component that is causing the misfire, the light may come on for models prior, but not for a direct misfire.
If the engine is running relatively smoothly, there probably isn't a misfire. If you can put it in drive, and the car doesn't shake or feel rough, misfire isn't a real issue.
What are you looking for? Do you have a specific problem, or are you dealing with emissions?

Let us know.

Good Luck and Merry Christmas

Answer 2

Loose definition! A "fouled plug" does not fire at all, - (or caused by bad plug wire feeding it), -it will be noticed by rough idle, and poor acceleration, - (also poor fuel mileage). So you will have a "dead" cylinder all the time! A "missfire" generally speaking is an intermittent kind of thing, - most common of them is "dropping firing" on a sparkplug when sharply accelerating, - when you let up on gas a little, it starts firing again! This will be noticeable, as you will feel a litle hesitation all the time the plug is not firing right, -and a "jump" in power every time it "hits" right! As power is applied rapidly, the explosions in cylinders increase in volume, causing an increase in compression, -- a marginal plug, or "weak wire" will not have enough "power" to make the spark jump the gap on the plug. This can also happen if the "gap" on the plug is too great, ( or the resistor in the wire going to it is partially burned or broken in places (or is jumping to ground before it gets to plug)! There is also another kind of "missfire" which is actually "crossfire"! On older cars that still use a distributer, you can have "spark tracks" inside the distributer cap (usually from having moisture in it at some time), - the sparks burn a very light "carbon track" inside the dist cap, which at times will make spark jump to other wire positions, - which makes the plugs fire at wrong times (in adddition to when they should).. this can do all kinds of wild things to operation of engine! However most of the newer cars have individul coils for each sparkplug wire, - (note a weak coil can do this also).I had an intermittent misfire on my Neon, - it burned out the coil in a very short while, - it was caused by a bad wire arcing inside insulation where you couldn't see it. I bought new plugs, but didn't get them in right away. This made the coil burn out, and since the coils come in a composite unit with 4 coils all together, - I had to by the "whole bunch" (over $100) . The car ran very well except when I tried to accelerate rapidly,-then kicked right in and ran just fine after I let up on gas a little (still accelerating).. So there is one example!--- I always check wires for resistance whenever I have them off plugs, - so that is how I found out about the bad wire!

Answer 3

If you have an older car with the wires exposed , you can use a spray bottle.. Spray a light mist on the spark plugs(yes they cause misfires too),plug wires and distributor cap. When a msfire is detected he egnine will run rougher and there will be a light ticking noise also you maybe able to see te spark jumping at the location of the misfire (low-tech, but it works and is very affordable)

Answer 4

The engine detects a misfire by gazing the timing of the crank sensor pulses. It senses which cylinder is misfiring by gazing the cam sensor position on the time of misfire. purely because it truly is the purely misfire code does no longer inevitably advise it is your purely misfire. initiate with the basics, in the adventure that your ignition wires are unique, replace them. G.M. wires dont delay properly previous 100k. you assert that you've ability to the injector, even though it also needs a floor pulse from the computing device such as an ignition coil does to reveal it on and stale. Injectors can bypass undesirable yet no longer that commonly. ninety 5% of all misfires are in various of circumstances via undesirable plugs , wires, corrosion on your coil towers, intake leaks(this may take position at idle) or coolant shifting into the cylinder. do no longer substitute your O2 sensor. An oxygen sensor is by no ability reactive adequate to come across a misfire. it would want to reason diverse misfires by handing over the incorrect archives to the computing device for gas trim mapping yet which will reason diverse misfires and different glaring operating complications. An oxygen sensor will change your gas trim from wealthy to lean an person-friendly of 20 to 50 circumstances in line with 2d. those are referred to as bypass counts The oxygen sensor is likewise used to envision E.G.R, operation on many vehicles. It won't be able to tell if a cylinder is misfiring.

Answer 5

i own a repair shop,and an easy way to do this is pull the plug wires one at a time,this will determine which one it is,,you might want to do this with an insulated pair of pliers though,sometimes it can shock you,,the only other way is to have it scanned,and see if it will show up that way,,usually though a small miss wont cause a check engine light ,so it wont leave a trouble code on it,,just be care full doing this ,,good luck with it,i hope this help,s.

Answer 6

If you have an engine missfire the ebgine WILL be shaking roughly.

Answer 7

car heating up