Hi All,

A couple weeks ago we got a lot of rain and the truck misfired like crazy getting onto the highway. After it dried out it drove fine but it has been 5 years since last tune up. Just did rotor, cap, plugs, wires with the exact same ones that were previously on it. Did it according to TSB. Now I am getting misfire but only around cruise and if I rev it around 2K RPM, but accel is just fine. While revving in garage I did get it to throw code cyl 8 misfire. Looks like my PCV is failing since I see some oil seepage so I have one coming to dealer on Tues.

Tune up Kit: https://www.rockauto.com/en/moreinfo...=1314573&jsn=3
Autolite 3924 (I did not check gap)

Any other idea what might be wrong? I have to drive up north to my parents to take their boat out this weekend. Should have left well enough alone...

Edit: It seems to be missing revving anything around 1800 RPM and up. Just took it for a drive and it's driveable but something isn't right. Also another thing the rotor was pretty difficult to get off, is it possible to twist the distributor at all?

Thanks,
Patrick

 

You aren't going to twist the distributor shaft by hand, unless it is broken. And yeah, the rotor does tend to become one with the shaft. I've had to shatter them with a hammer to get them off before.

How's your fuel pressure? I would be real tempted to pull the plugs, and check the gap. They hand out in those boxes for quite some time before they actually get installed, anyone's guess what the gap is at that point.

Cylinder 8 misfire is sometimes a sign of a clogging cat as well. 'Nother question would be, how old are your O2 sensors? Does the truck run better with them unplugged?

 

02 is about 4 years, Fuel pressure is fine, I forgot to mention I just replaced fuel pump about 8 months ago. There was no puddling oil in Keg and I put a magnaflow high flow cat on too about 4 years ago.

Weird thing is that it ran just fine before this, other than the moisture issue so I fell like it has to be something with cap/rotor/wires/plugs. I'll check gap tomorrow, luckily this is an easy job to redo.

Worst comes to worst I have to borrow my brothers truck that's out of town to get the pontoon out, but it's a ford....

 

I know where I'd start. . .

Remove the walmart Autolites and put in genuine Champion RC12YC gapped to 40 thou. Then make sure each and every wire is perfect and snapped in place. I have actually switched two of them twice in my life and caused a rough idle. No misfire codes though. And sometimes the rubber boot will twist around and cause the wire to not attach properly. And sometimes wires are bad from the package. I've only ever used Napa gold wires and champs. Never had a prob.

 

Will do that next. I usually don't go cheap on parts but have ran these for a while with no troubles. I threw in all the old plugs just to see, same symptoms so it could very well be these wires. Idles fine and acceleration is fine, it's only when I'm at a slight cruise around 25-35mph it sputters.

Where is the best place to source those plugs and wires, just the local NAPA? I need to redo it this week so I can't wait for shipping.

Thanks for the help guys!

 

The autolites are likely fine. I have ran them for years. (too many bad experiences with champion plugs..... everyone has their favorites. )

How about disconnecting your front O2 sensor, go for a drive. Still same symptoms?

 

Yup, forgot to mention I did that as well, same thing. I'll try new wires next. Has to be something I just replaced. PCV seems to be spitting a decent amount of oil out too but I won't get the dealer part till Tuesday. Thought that only made the engine act up at idle though.

 

PCV is just a controlled vacuum leak. It is always active. If flow rate is too high, it can cause some interesting issues.

 

Have a look at cap, I had one of the wires around it get caught underneath it once.

I second that, The longest time i could get of champions to run without a miss was about two years. Autolites never had an issue with them.

 

I pulled the cap off last night to make sure it was seated correctly and everything looked fine. I started to prep tonight since I have to head out shortly. Gap the new plugs I took out last night to .04, they were actually all over the board out of the box.

Is the Napa kit supposed to come with wires this size?

3 long - 1, 2, 3
1 med long - 4
1 med short - 5 (over cyl head), 6
2 short 7, 8 (over cyl head)
2 coil

Just want to make sure it wasn't packed wrong and need to return, I think all kits I have gotten in the past have 2 of the med long. I think my matching above is right.