i have a 1996 dodge 4x4 with a 5.2 that has 234,000 miles...yes its real it has never been rebuilt as far as i know.....OK about 236 miles down the road i get a code pop up 300,301,,so i un plug my battery and another 236 mile same thing ,i have new plugs,wires,rotor button and cap.....and climbing hill i can fill the miss fire but i cant figer it out why and im getting ****ty gas mileage to.my Numbers 8 plug is wet..so i got a bunch of misfires all over can ya help

 

what kind of plugs did you use? also have you done the plenum fix? and you have a magnum motor, and from the factory they got around 10MPG epa est. around 11MPG

i would say do the plenum fix, DIY found here on the site, and i would either go back to the factory champions, or champion truck plugs. as im running boschs and have a slight miss at idle. these magnum motors are know to not like certain plugs, what may work for me, might not work for you. but it seems that these motors do like the champions regardless.

 

be sure to follow this TSB for running the spark plug wires as well:

http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8.htm

 

Yeah, definitely do the spark plug wire TSB. Also check to see if you your cat's clogged. A bad belly pan (plenum gasket) won't cause a misfire. The bad gas mileage IMHO is caused by the misfire you have. Double check to see if you installed the plug wires properly. If not, that'll DEFINITLY cause a misfire. just a couple of thoughts.

 

ya, i know it wont cause a missfire, however he did mention that his #8 spark plug was wet, though he didnt say with what, but i threw the plenum gasket in there, as all magnum motors have this issue.

the plugs could make a difference as well.

 

If the distributor is original, It could be pretty sloppy by now as well as the timing chain.

 

Might as well throw a bottle of fuel injector cleaner into half a tank of gas. Mine had a cyl 5 misfire. Changed the plugs, wires, cap, rotor and did the TSB -- still misfire. After that, I tried the Gumout gas treatment and that fixed it. Worth the $4...

 

sorry the plug was wet like it didnt fire at all.it was wet with gas.i made shure the plug wires was in the same place as the factory had them all nice and neat not crossing..i also tryed the best gas out there and 3 things of fuel injector cleaner.no change

 

Have you checked the coil? Also what plugs are you currently running? Its been stated many times, Magnums are damn finicky on plugs. I would also try a can of Seafoam in the tank, as opposed to fuel injector cleaner.

 

if its just the # 8 cylinder I would double check the cap and wires as well as replace the plug or at least swap it with another ....btw autolite 3329 plugs are a favorite around here for our trucks and they are cheap...