Another check engine light question!!
 

Well on the way home from work to day my check engine light came on, again. I had changed the plugs in it in the early fall, and shortly after my check engine light came on and it seemed to be missing, so I checked to see if the plug wires were on tight and one was loose, pushed it on and it was ok for 2 months, and the same thing happened this time I took it to a dealer, and they said it was a missfire on cylider #8, and they put some dielectrical grease on the plug wire ends and told me if it happens again to replace the wires. Well it came back about 1 month later, so replaced the wires and went away. But now it has come back and I don't know what to do, Would it be a coil? or a spark plug? I gapped theme properly, I put dielectrical grease on both ends of the wires so I don't think moisture is getting in, any ideas???? (was thinking about buying a scanner, one from mac tools) Thanks guys

#8 missfire
 

i,m gonna asume that you,ve got some miles on that 97 so you might consider looking at the oxy sensors (3). if you have a cylinder miss firing your gonna know it. if so pull the wire and if no change "bingo",if it gets worse then it,s another cylinder. if the light is on but you have no miss thats noticable,then a scanner will same time and agony.but i,m willing to bet that it,s an oxy, esspecially if you,ve done some exhaust mods (more flow,more heat) good luck

I have had the same problem since putting in my Jacobs ignition and the Jacobs plug wires. About every couple of months it will start to miss fire and I have to go under the hood and push all the wires down.
I am now looking at getting a set of Ford Motorsports Race wires. They have the same shape of the orriginal equipment which gives you a place to put your thumb and snug them down. So far I havent been able to get any information on them to see if they will hold up to the Jacobs hotter spark. If you come up with a fix then let me know.

As far as the plug wires popping loose, sometimes you get an air bubble in the boot which heats up and causes the wire to pop off. Another thing is if the plugs aren't tightened properly, gases can escape around the plug and cause the boot to pop off. Make sure you use good quality dielectric grease, the cheap stuff can heat up and cause the same problems.

Some guys will use a piece of wire, bent at one end and the bent part placed inside the boot, then they will put the ignition wire on and pull the wire out, this way it makes an opening for air to escape as you pull the wire out. I guess some dodge engines have these exact problems.

Just some things to think about.

-Jon

Do you wash your engine?

In addition to the above possabilities water can get in around the boot and it will boil and cause the boot to pop up

Good luck!

It could be your coil. I had a small crack on the underside of one of my coils (plastic cover). Whenever it got get it would start misfiring; then it would stop as soon as it got dry. I eventually replaced the coil and haven't had any more problems.

I don't wash my engine, haven't since I got it, I guess I'll try to push all the wires back on and see what happens!