2003 expedition misfire on #1 cyclinder during the first 10,000 rotations

these have a problem with coil packs and ignition wires. check the plug it may need replacing, but change all the plugs not just the one. you could have a dirty or a bad injector for that cylinder or even a vacuum leak at the intake for that cylinder. something else is you could have poor compression on that cylinder.

5.4 Liter? If so you should have a coil on plug ignition. Pull the number 5 coil and check for spark. If there is no spark swap it with number 1. If there us still no spark than replace the coil.

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P0300 Random Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
according to this fault codes first mark ignition coils
3 ---------------- 6
2 ---------------- 5
1 ---------------- 4
RB-------------LB
this right banks and left bank, please remove Ignition coils with lids and spark plugs from right bank and swap with left bank, if fault code change as
P 0304 Cylinder 4 Misfire Detected
P 0305 Cylinder 5 Misfire Detected
P 0306 Cylinder 6 Misfire Detected
You can Identify it's a faulty ignition system then next swap ignition lids from ignition coils be careful each coils have two lids one short and other long bit deference and when you remove and fix it to the car keep in mind correct order because each coil two different fire for two spark plugs don't mix up, if you mix it can create the fault code.if you detect any fault ignition coils or spark plugs or lids replace that and also whether god or bad recommend to replace spark plugs, find the right that's most important thing, if this way couldn't found the any ignition fault next step is check fuel presser, when the engine running fuel presser must be around 4.5 bar without engine running must be 4 to 6 bar if the fuel presser too low need to check two different things one is fuel pump other is fuel injectors, in this case you can swap injectors from right bank to left bank and find is the injectors leaking, if not leaking faulty fuel pump.is this information helped you? if yes please leave a comment,

Fig. 2.5L (VIN N) Engine Firing Order: 1-2-3-4-5-6 Distributor Rotation: Clockwise





Fig. 2.5L (VIN H) Engine Firing order: 1-2-3-4-5-6 Distributor rotation: counterclockwise




Fig. 2.7L Engines Firing order: 1-2-3-4-5-6 Distributorless ignition system. One coil per cylinder


Hope helps (remember comment and rated this).

Third cylinder back on the passenger side. I'd recommend changing all 8 coils and spark plugs. These coils don't last long, and once one goes, more will fail soon after. This job also requires removing the fuel rail to gain access to the coil and plugs. I personally have the same SUV and went through the same issue!!

1. Swap two ignition coils between #5 cylinder and another one.
2. If the #5 cylinder misfire problem is still present you must check up wire by wire the electrical supply cable from the Engine Control Module (ECM) to the #5 ignition coil. Repair damaged wire(s). The last piece out of order will be the ECM !
3. Inspect also #5 spark plug if it is wet or dry. If it is dry then you must verify the #5 injector!

CODE 27 - Injector Control Circuit, output driver does not respond properly to the control signal

Code 27 MIL light options: OBDII
P0201 - Injector #1 Control Circuit
P0202 - Injector #2 Control Circuit
P0203 - Injector #3 Control Circuit
P0204 - Injector #4 Control Circuit
P0205 - Injector #5 Control Circuit
P0206 - Injector #6 Control Circuit

CODE 43 - Cylinder Misfire, or Ignition Primary Circuit

CODE $# MIL options: OBDII
P0300 - Multiple Cylinder Misfire
P0301 - Cylinder #1 Misfire
P0302 - Cylinder #2 Misfire
P0303 - Cylinder #3 Misfire
P0304 - Cylinder #4 Misfire
P0305 - Cylinder #5 Misfire
P0306 - Cylinder #6 Misfire
P0351 - Ignition Coil #1 Primary Circuit
P0352 - Ignition Coil #2 Primary Circuit
P0353 - Ignition Coil #3 Primary Circuit

Could be bad coils, or someone switched the two wires if it has wires.

cylinder 1 misfire and low compression. Plugs and wires changed plus new fuel injectors. The engines still misses and no one can find the cause. When put on the computer it read misfire cylinder 1.

This is a pretty common problem. I would change your valve cover gaskets. They run around ~ 50 bucks. If they are bad it will leak oil into spark plug well and cause a misfire. Very known on the 740.. Also if tune was not anytime not too long ago id change spark plugs while you at it. Then clear the computer and if you still get misfire on 8 try changing the ignition coil which is right about the cylinder with cylinder ignition coil 5. clear the computer. if you get random misfire and misfire cyclinder 5 after then its your ignition coil. parts store runs around 100 bucks