hey everyone I'm excited to join this forum. I have an 03 ram 1500 with 150k on it. it has a pretty obvious miss at idle that almost feels like it has a cam in it. I have replaced the plugs and wires, cap and rotor the pcv valve and I did the intake and plenum today because it was bad and I'm still having the same issue. I've done the compression test. checked everywhere possible for a vacuum leak and nothing there. I've tested my injectors and I've checked my spark. everything has checked out good. I've also cleaned my IAC. I am at a loss and I've gotten to the point where dumping a can of gas and throwing a match at the truck would make me feel better. any advice would be greatly appreciated. what stumps me is it was smogged 3 weeks ago with zero issues. the truck runs great over 1k rpm but the second it drops to idle we're chuggin and the truck has a steady shake. this truck is going to make me go broke. lol

 

Some of those symptoms sound like a broken valve spring, but "cap and rotor" leaves out the Hemi. I'm not so familiar with the 5.9L - does it have a throttle body? I remove and clean the TB on my Hemis about once a year. A Sea Foam treatment around then, too.

 

i've cleaned throttle body and now that I have done plenum and the truck seems like the miss is more obvious now

 

I should also add that it does in fact throw a 0308 code but it is never consistent as to when. sometimes after 10 miles sometimes after 200 miles.

 

I should also add that it does in fact throw a 0308 code but it is never consistent as to when. sometimes after 10 miles sometimes after 200 miles. the other question I have is could it have fouled my plug?

 

#8 misfire. Could be plug or injector related. Maybe do a compression check to rule out a head gasket.

 

compression is good. it has new plugs and wires. I put a new plug in it today and it seemed to help it somewhat. but it still has a slight lope to it. I should add that I have a throttle body spacer and k&n intake on it akso. but I've owned diesels for the last 10 years so this is fairly new to me.

 

Did you disconnect the battery when you did your tune-up? By the time you were done, that would've provided enough time for any existing codes to clear. You could buy another plug for #8 and see if that helps.


Go to Advance Auto or similar and get 3 bottles of Chevron Techron gas additive, smaller bottle. Run tank to 1/8 of a tank, pour 1 bottle in tank and fill to a half of tank with super unleaded. Repeat this 2 more times. Drive hard on all these. Fill all the way up with Super Unleaded when these 3 bottles are done.


SJ03