I have a 1999 mercury cougar v6 2.5l and says that #5 cylinder misfires. When you go above 30mph to highway speed it starts to buck and kick. Check engine light also flashes and then stays on completely. Check the spark plug and it was burnt to a crisp, going to change the spark plugs and wires soon but what else could it be. Any solutions
SOURCE: I am getting a misfire
I've got a 2002 Grand Prix GTP 3.8L Supercharged V6, nearly the same motor.
I had the exact same problem, misfire on Cyl. 5 and random/multiple misfire.
I replaced all the wires, plugs, coils, and even the ignition module. My next thought was either fuel or exaust.
Replaced my Cat. with a 2.5" ZZP downpipe, and the car ran alot better, but still had a tiny bit of hesitation over 4000rpms.
So i checked all the fuel injectors, and the #5 injector was bad.
To check, get an ohm meter, remove the injector connectors, and contact the 2 posts inside the injector. They should read between 12.4-14 or so.
Mine was at 11.2.
Replaced all the fuel injectors, and she runs like a champ
SOURCE: 2000 mercury cougar is hestating when you step on
a multiple misfire code can relate to a fuel problem check filter pump pressure let me know alan wrench
SOURCE: MIL indicates cylinder misfire on 1, 3, and 5
Check for
vacuum leaks on intake manifold,
the air tube between the air filter.
intake manifold vacuum hose.
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clean throttle plate with Berryman carburator cleaner
SEE sample picture HERE
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Also remove carbon built up behind the EGR valve and the EGR passage tube.
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Vacuum leak WILL offset the intended 14.7 to 1 air fuel ratio.
More un-metered air (leaks) will lean out the fuel mixture.
Use small amount of Berryman carb clearer at potential air leak area will help you identify trouble spot.
At idle,just spray and listen for the RPM surge.
The in-rush of carb clearer will increase the RPM on the motor.
Record the problem spot(s) and address it later.
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EGR carbon built up require 2+ hours to clean from start to finish.
You will need a new EGR base gasket before your start.
Locate and remove the EGR valve after the vehicle is cool down.
Carefully record the connector and vacuum line (for older vehicle) location by drawing an easily to follow diagram.
Remove the EGR valve.
Inspect the location of the carbon built-up inside the valve and the EGR passage tube.
SOAK these areas with WD-40 spary.
You will need a small screwdriver,cloth hanger and lot of newspaper and time to get this cleaning done right.
RE-SOAK the carbon and let it sit for over-night will also help.
One the last round,pass a shop vacuum of the EGR valve and the passage pipe.
Install the new EGR gasket and connectors.
Allow the vehicle to warm up outdoor to burn up any remaining WD-40.
Take it for a test drive.
Please rate my answer if it's useful to you.
Cheers,
Mustgo
SOURCE: Took my car to have check engine light checked. It
In modern cars so much can go wrong to indicate an issue and a computer in the car can get confused as to what is really occurring. In most cars a misfire indicates either an incorrect firing order, shorted wires, bad plugs, or bad coil. Since you have replaced the wires and plugs we can rule those out. Im also assuming after the second engine code you pulled #2 plug and made sure it wasnt fouled with oil, was gapped correctly, and reinserted. To produce a sufficient spark for combustion the alternator sends power to a "Coil" which is in reality a storage point that then sends an amplified electrical current down the spark plug wire to the cylinder to fire the plug. If the car is truly misfiring you will notice a rough idle, fluctuating RPM's, and lack of acceleration. If you are experiencing any of these I would look at replacing the coil. If you arent experiencing any of these I would have the code cleared again and complete one drive cycle 100 miles and then have codes read again. If you still get a Misfire error some other causes known to occur with Rio's are fuel filter issues, gas caps, and fuel injector issues. Although rare, these can cause issues with the cars fuel delivery and emissions which can confuse the sensor in the ECU. I would try injector cleaner, replace the fuel filter, and gas cap . If funds are an issue then based on symptoms I would start with injector cleaner first $3, Filter $12, Gas cap $12, Coil $48 to $200+
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