My 1999 Finally left me stranded

Morning! How often should coil packs be replaced? I looked at my paper work and can't find that they have ever been changed. I did a major service at 190,000 and they were not replaced but the spark plug wires and plugs were replaced.

 

There's no set interval to change them. They work until the magic runs out. I have some 40 year old coils that are still in spec and working fine. Your FSM will have the procedure and specs for testing them for resistance. Specs from fsm for 3RZ say 9.7-16.7 kohms cold, 12.4-19.6 hot.

 

I think mine are original... I was thinking once i get in there I might as well replace them, but that might just be throwing away $...

 

Swap the problematic cylinder coil with another one like I stated earlier. It's an easy check without spending money.

 

I've had to replace mine once before, I have 260k on my 2002.
And recently had a dodge misfire and it happen to be a cracked spark plug. Just something to think about.
Your intermittent misfire leads me to believe an electronic component of some kind, as everyone else has stated.

 

I did the coil swap. pulled the negative battery cable. Started the truck and let it run while revving it up for about 5 minutes. No check engine light now that I cleared it. I guess I need to take it for a spin and see what happens. It had a high idle but after revving for several minutes it went back to normal.

I didn't pull any plugs, probably should have while i had it all apart...

Could it be a vacuum leak?

 

One step at a time.

Vacuum leaks are not self healing.

 

Took it for a spin, no check engine light... I'm thinking the coil is intermittent. Maybe something was loose?

I might just order one in case it happens again I can swap it out.

 

Can't remember the parameters, but I believe you can test the resistance on the coil to see if it's within spec.

 

My truck285K has been towed twice in twenty years both times plug wires Misfires

 

Morning! I drove into town on Sunday and sure enough the check engine light came back on. I knew it was going to happen again as i hadn't done anything but the coil swap. Yesterday, I threw new spark plug wires and a new spark plug in cylinder one. Drove it yesterday, then to work today (45 miles) and no check engine light. I am about 90% sure it was the spark plug wires. The old plug looked good when I pulled it but I went ahead and swapped it out.

Thanks for all the suggestions and help!!

 

Was it throwing the same code?

 

Everything you have described sounds like plugs or wires. At 60k miles they are due for replacement anyway. The OEM plugs for the 3RZ are rated somewhere around 30-40k miles FYI. They are standard copper plugs. https://amzn.to/3QeF6Oc DENSO K16R-U11

 

Yes, misfire cylinder 1.

 

Cool good job getting it taken care of

 

Like you only changed the one spark plug? What about the others? They've all done (roughly) the same number of miles.

 

Interesting, my old mechanic would always let them go at least 60,000. Honestly since I moved 2 times in the last 4 years I haven't been on top of my maintenance except oil changes and tire rotations. I need to do the other 5 plugs just to make sure

I will do the rest. I have been sick and just wanted to get the truck running.