I changed my plugs and wires, then I got the same problem back about 5,000 miles later, the same code for a cylinder misfire, so I immediately blamed the cheap Xact plug wires that I had bought from Advance Auto, so I went and got a set of Autolite Professional Series wires, and I changed them. My problem actually got worse! I checked the wires, pulled them, greased them and put them back, and it started fine, idled great, but it is still losing a cylinder in the rpm range of 2,000-2,900. I don't know! Plugs or coil packs? Computer? Help, please! I know that y'all will know what is wrong, and thanks in advance for any help that you can give me. Thank you all again!

 

You may want to consider that the fuel injector could be dying, or clogged.

 

Would this be something that just happened all of a sudden, and how do I check it or change it? Could it be a fuel filter or a pump? Sorry to ask so much, I just have no idea this time. Thanks!

 

I brought this up becasue the most common reason for a misfire, outside of plugs and wires, is a faulty injector. Since it is happening at in particular RPM range, it makes me think that one of the injectors is not keeping up.

Do you know if it is just one cylinder, specifically that has a misfire??? That was the impression I was under; that it was a specific cylinder.

 

Yes, it's just one cylinder. It felt like I had lost two or even three, and the I took of the (new) plug wires and reapplied them, just to make sure that I had them on good, and it did better, but it's still missing one cylinder. I am not sure which one it is, though. I wish it would just be a bad plug. They're fairly new, but still, I may have got a bad one. How do I find out which one is misfiring?

 

If it will do it while setting still and someone loads the engine, then this will id the missing cyl. Take a test light and ground it well, preferably to the battery if your ground lead will reach. Then back probe each of your wires between the wire and the boot. Be careful not to probe into the wire or you will ruin your new wires. This will ground the spark to the cyl and will make it miss. If you have a cyl that does not miss when grounded, then that is your misfiring cyl. Hope this helps. Remember this will only work if it is missing while performing the test.

 

Hi Pickup

Just some thoughts....check your local parts store..."spark plug tester" Not expensive.

Havent looked lately..so not sure still available. Its about 5" long..has built in test light..metal tip on end. Can also use on wires. The one i have is old/abit erratic with new wires..i think insulation now a days is better. But worth a try if you can find one. Other wise to really pin point other than trial and error..you'll need oscillocscope/test equit. You can check plug wires with an ohm meter..but need spec. sheet..i dont have.

Also tester for fuel injector...shows how its working.

A long shot...As i recall someone here posted similar problem after plug change. They reset the "pcm" and for what ever reason..it was ok after that. Of course doing battery disconnect will probably erase any OBD P codes.

I dont really know about 'pcm' and codes. But i do believe they get erased on disconnect...and may/maynot get thrown again?
I know...I just found out by doing that but not for your problem.

Another loooong shot...go back to OEM factory plugs. I havent done it but i think coil packs can be tested. Also look for arching/tracking and where wire plugs in at c.p... is clean.

Good luck...hope you find/fix problem. OT

btw....you didnt cross wires did you?