Depending on the manufacturer, the cylinders are numbered to specifically identify each. On an in-line V8, #1 is on either the passenger side or the drivers side, depending on the manufacturer, and recognize that Jags are manufactured in England where they drive on the wrong side of the car. Then, again depending on the manufacturer, cylinders are numbered one of two ways, down the same side as #1 (1 through 4 on that side) then across and down the other side (5 through 8 on the other side). However, some manufacturers number differently with the cylinders on the same side as #1 being all ODD numbered cylinders and the opposite bank being all EVEN numbered cylinders. What I'm saying is, you'll need to get your hands on a reference book. Check your local library, that's often a great resource.
Well...the misfire on 1 and 3 would explain the rough idle. The misfire could be from worn plugs, wires, bad coil, or bad injectors.
The 5.4L engine uses a coil-on-plug system to create the spark for each individual cylinder. I have heard of an instance where both coils went bad at the same time on a V10 Ford Engine with the Coil-On-Plug system. One thing you can do is have your Trouble Codes scanned (Auto parts stores usually do it for free if you don't have a scanner of your own) and find out what cylinders are misfiring. Then, swap the coils of the two misfiring cylinders with two coils of cylinders that aren't misfiring. After this, have the codes checked again, and if the misfire trouble code jumps to the 2 cylinders that you moved the coils to, the coils are both bad. If the trouble code indicates that the original two cylinders are misfiring, then the problem is elsewhere... Your V8's Cylinder Arrangement is as follows: Firewall 4 - 8 3 - 7 2 - 6 1 - 5 Front of Engine
If it has a circuit malfunction, or is causing a misfire.
try checking your spark plugs. Or the ignition coils, especially after a heavy rain. Buy an ODB II scanner (as low as $40, you will likely get a cylinder misfire code)
WOW Sounds like you spent alot of money. First lets get you on the path of saving some of that money. Go online and look up AUTEL Maxiscan MS300 OBD II code reader. This is a relatively inexpensive (less than $50.00) scanner and it works very well for most home uses. You need to determine which cylinder has the misfire and if it is above or below 1000 rpms. Once you know that you can troubleshoot the coil and plugs by simply taking the suspected bad one and put it in a different cylinder to see if the misfire moves to that cylinder. It's cheaper than replacing all of them. If you know it is not the spark plug, coil or the spark plug boot the next thing to check is the wire bundle connectors to the coil packs.A misfire is not a killer so you have time to wait for your scanner to come in and go from there. That scanner can save you and your friends and family a ton of money. Well worth it. Good luck.
Misfire on Cylinder 6 would mean replacing the spark plug (less than $5) or coil (about $80). Cylinder 6 is on the front. (easier to reach than #1, 2, and 3). This is usually just a bad plug, but could be due to water in your spark plug hole or in the gas. If it only happened one time, there is probably no need to worry unless it occurs again repeatedly. If so, you should troubleshoot your ignition system and perhaps the fuel injector for that cylinder. Keep in mind that since it only occured on cylinder #6, it would not be caused by anything that would effect the other cylinders, say for instance low voltage or a bad fuel pump. If A Coil Is Bad You Will Also Get An Overtemp Code. Along With The Misfire Code, almost never is this a bad plug unless someone just replaced their own plugs and have the gap messed up or the wrong plug in the engine.
Probably a misfire condition, however you will need to hook up a scanner to read the codes.
Emissions related or a misfire. Get the codes read with a scanner.
Use a scanner to see which cylinder(s) has the misfire if its two that are fired by the same coil then replace the coil if its just one its probably a bad plug or wire The coils are unbolted by using a 5.5 mm socket
A flashing check engine light means you are doing serious damage to your catalytic converter due to repeated misfires in one or more cylinders. If you get a code scanner (or go to an autozone, oreilly's etc. where they scan it for free) you will see a code such as P0301 (misfire, cylinder 1). Your catalytic converter is probably shot now. If it is and If you live in a state that does emissions inspections you will need to get the converter replaced after you fix the misfires. An old spark plug will generally cause the misfires.
That can be caused by an number of reasons. The most common is a misfire or a multiple cylinder misfire. This can me caused from an internal oil leak into the spark plugs. You can go to an Auto Zone or any place like that and they can hook the Jeep up to a diagnostic machine to let you know what the code is. That will help you figure out where to start to fix the problem. If the light is flashing do not drive it because it is something more serious.
More then likely you have some bad spark plugs are plug wires.I have seen the coils that are on top of the valve covers cause it too.You really need to have the engine scanned with a engine scanner to locate the problem. It could be any of the 8 cyclinders.