So I'm goin to do a tune up this weekend, i'm goin to get new plugs, wires, cap and rotor, and air filter. just wondering what would be the best for a 01 sport 3.9L, what i should be getting wire thickness, cap and rotor number... like what size or what ever (Sorry not a mechanic), and plug spacing and brand??

 

I just did the full tune up on my 03 Ext cab 2wd with the 3.9 V6. I went to O'Reilly's and picked up everything. Go with the OEM grade plugs. Our trucks don't like platinum plugs. They only had 1 type of wires so that's what I got. The Borg Warner cap and rotor were only a few dollars more each so I went with those also. My truck has 175,000 miles on the clock but I have only had it for 6 months. I think the cap and rotor were original. I saw immediate results when I did the tune up. Hope this helps.

 

The plug # is all over the board. It's one range down from stock, on autolite's i believe. I'll look real quick.

AL 3923

 

ok thanks.

for the cap and rotor is there a specific part number for them??

and for the plugs 0.040 spacing is what i've heard the most, that good??

 

Shortly after I got my truck I replaced the cap and rotor with an aftermarket set as I seem to remember the stock ones weren't very good. I ended up getting Borg Warner with brass contacts. That was 100,000 ago and it hasn't missed a beat.

 

Napa cap and rotor, made by Echlin, with brass contacts are Napa part numbers MO 26 and MO 28. The Belden Premium plug wire set at Napa is very good too, a lot better than the $20.00 cheapie sets you find at other parts stores. Autolite 3923 plug works well. So does the NGK plug, NGK part #ZFR6F-11. NGK says gap them at .044", I gapped mine at the Dodge recommended gap .040", no problems and my truck is running great. The 3923 is one heat range colder than stock, the NGK FR6 is the stock heat range plug. I do not know what the part number is for the NGK plug that is colder. I think with NGK the higher the number, the colder the plug so I think the 3923 equivalent would be a FR7F, but I am not sure on that.

The colder plugs work well in our Magnum engines, they can help eliminate ping. I tried 3923's and still had some pinging so I installed a 180 degree thermostat and the combination of the tstat and plugs finally did get rid of the ping in my truck. I ran 3923 plugs for a long time until I recently learned Autolite plugs are now made in China and the quality is not so good anymore. That was back around March I guess, when I did my most recent tune-up. I decided to try the NGK in a stock heat range and they are doing fine, still no ping and I get good power and the same MPG. Some NGK's are still made at their factory in West Virginia and some NGK's are made in Japan but that is OK with me as long as they make a good reliable plug.

Jimmy

 

The 3923's worked well for me. I've got about 90,000 on my 1st set.

 

I used all the NAPA parts as well when I used to have a 3.9. They worked well along with the NGK plugs. I only had the truck another 6 months after I did the tune up but they worked great for that time period.

 

k thanks guys... I looked at my truck and realized that the distriuter is in a pretty tight spot and i dont want to spend time trying to get at it cause i'm on call 24/7 for search and rescue so i'll just get the parts and when i take it in to get the brakes done i'll ask them to put in the plugs, cap, rotor, etc. because i have those days booked off