I have a chugging enging at low RPM such as at a stop. I changed the plugs, wires and still a problem. Auto code shows #1 not firing so I changed the coil and still not better. In addition I looked up the firing sequence and was told it was 1, 3, 5 front from passenger side in, and 2, 4, 6 firewall side from left to right. I traced each and the front came up 1.3.2 in the front. I replaced all wires per the information above and the car would not even start. I put back to the original 1.3.2 and now back to the original problem? Can you help and also tell me the correct wire sequence?
My info showed this for 3.4 firing order. 123456. If the you think the problem is spark issue, you can use a digital multimeter, take an inductive reading from plug wires, engine running. You don't take the plug wire loose or penetrate the insulation. One meter lead goes to ground, the other lead, just touch the plug wire. As an example, say four wires show around 1/2 volt and two show around zero. If the two that show zero are on the same coil, I suspect the coil first. You could swap the coils around, see if problem follows the suspect coil. If coil is ok, I suspect the ignition module. I'm talking about no spark. There are other issues that can cause a misfire. I just wanted to add, when using meter with engine running, you have to be careful not to get the meter leads caught in belt--pulleys--fan or anything.