Hi,I have a 1998 dodge ram 1500 i just bought recently as a work truck.I am dumping money in it left and right.The problem i am having is that there is a misfire cylinder 8.I bought all new plugs,wires,checked the cap,i'm stuck i also got a code for injectors 4 & 8.I bought this truck form a police department auction and it was sitting for about a year.Every time i replace something it seems to be getting closer.Thank you for your help!

 

Check the plenum... look at the top sticky on this board for more info.

What code did you pull for the injectors?

 

I've read that it's normally the number 8 cylinder where the heads crack. Not sure if that could be the problem, I hope not though.

 

Well for the injectors I would swap them for two on the driver side bank like 3 and 7. to see if it's the injector.

And for the misfire on cylinder 8, it could also be an injector so you could swap it around also. But sadly when I had a misfire on 8 it was a cracked head for me. I ended up with two junk yard head and had them redone at the machine shop. If I ever had to do this again I would get a new set of heads from Clearwater.

 

#8 misfire can also be caused by a clogged cat or misrouted wires. You've been dumping money left and right because you aren't diagnosing the problem. Replacing parts in a haphazard fashion is no means to correct a deficiency.

 

I believe there another #8 misfire thread from last week floating around...why is it know one understands how the search function works?...I think I have read here (more than once) that #8 misfire is commonly caused by a plugged cat which is commonly caused by the blown plenum gasket which is commonly caused by (take your pick) the plenum manifold bolts being two long and not properly sandwiching the gasket or the steel plate haveing such a drastically different expansion and contraction rate than the alloy manifold..bottom line is these are all common weaknesses in the design of these trucks and their are thousands of threads already here answering these questions over and over again..its always wise to you search function first then ask questions when you know the answer isnt all over the forum...Just an FYI for the future on how a forum works, not insulting anyone here...

 

I am sorry for not using the search feature and i was also unaware that this is a common problem.I own an 04' Ram 1500 and no problems but the lightning bolt.Thank you for your help.

 

The codes are (P0204)-(P0208)-(P0308) Injector Circuit 4-8

 

im having the same problem on my 5.9 98 ram 1500 cylinder 8 misfire...plkugs were bad changed plugs wires cap rotor. reset codes using snap on modis scanner....next day check engine light on and scanned for cylinder 8 misfire...i did a misfire counter and only on cylinder 8 i got about 35 in a minute of running at various rpms...i did the fuel injector kill test and all my injectors are operational...runs good just seems like lackin full power...any suggestions? pull off cat n check?