I started a thread a while ago about my '01. I still cant figure out whats going on.

I replaced the plugs a few weeks ago, after replacing I noticed a significant miss at idle. Smooths right out when I get on the gas. CEL didnt come on for a few days, when it did, I got the code checked. Random misfire, cylinders 3 and 6 misfire.

I used champion plugs. I've checked for vacuum leaks (cant find any). The coil pack, crank sensor are both fairly new. I just put a new head gasket on it. The head that's on there is still the original 0331 head that cracked, I used JB weld on it so I know that could cause me some issues but I have no coolant loss so I think it's holding. I dont think that is what's causing my issue.

My idle is normally at the line below 1000, it's now halfway between that line and the line below it. It doesnt stall but it does feel a bit odd.


In a few minutes, I am going to go re-gap the plugs, check the coil pack electrical connections, pull the throttle body and clean it out and try to re-check for vacuum leaks with some carb cleaner, and replace the ccv elbow (Im reasonably certain that's clogged).

I'm hoping cleaning the throttle body and replacing the ccv solves my low idle, but I'm still mystified at the misfire.

Any thoughts on what to check would be very helpful!

 

very possibe tro get bad plugs

 

Right, I'm wondering if I did.


I pulled them. I took some photos, I've got yellowish white buildup on them after only a couple hundred miles. The old ones that were in there for 30,000 looked completely normal.

Something is fishy.

I have new plugs in, the really significant miss is gone but it's running slightly, VERY slightly rough at idle. I cleaned the throttle body (which was pretty bad) and the idle still isnt back up to where I'm used to it.

It's completely driveable right now, but I still dont like that little bit of rough idle. And Im concerned about the way those plugs looked after such a short time. Any thoughts?

 

did you clean the iac and the hole it mounts in

 

500 rpm is correct for a 2001 with the 4.0 and the heater/A-C turned off and engine fully warm.

 

plug color could just be them getting heated up and used starting to discolor

 

Mine has always idled at around 7 (best guess). Pretty much right at the line below 1000. Ive had it since 30,000 miles, I never looked at the specs so maybe Ive been idling high all this time?

 

very possible when you turn the ac on it idles up

 

OK guys, take a look at the pics if you dont mind and tell me what you see going on here. Keep in mind, this is only 2-300 miles.

 

look fine all black or wet would be something to worry about a plug should be a light tan in color when running correctly

 

plug reading

 

Free, thanks for that. I referenced that same illustration in the back of my Hanes but nothing looks like what I have, at least to me. The yellowish color is what really gets me. Maybe Im just being paranoid but something still just doesnt seem quite right.

 

like you said it only has a couple of hundred mile on it its just starting to change color, did you clean the iac and it mounting hole out

 

Sure did, whole throttle body is clean as a whistle now.

 

that prob why it idles lower its all clean, plug could be a little yellowe from left over cleaner getting burned