Engine runs poorly after tune up

[amanda2des]

Sooo.... I recently purchased a 99 Dodge Ram 1500 4x4 automatic with the 5.9. It’s a project truck I hope to get on the road fairly soon. My first mission was to do a full tune up as it was clear this has been neglected. Prior to the tune up the truck had an obvious misfire but idled and ran without issue. During the tune up I found a spark plug wire had been let to rest on the exhaust and burned in half, other than that everything seemed to be in order just well over due.

In all, I changed the cap and button, plugs and wires, starter, and fresh battery. My issue is now the engine is hard to start, idles high and rough, then stalls out unless it’s given throttle continuously.

I have verified the firing order, all plugs were gaped to .4 and are tight, cap is tight, button went on correctly, verified spark to al cylinders, battery is new charged and cables are clean and tight, starter is new.

I’m looking for advice on what to check next, what I may have done wrong, or if anyone has experienced the same issue. I have limited tools and probably even less knowledge, appreciate any help I can get, Thanks!

 

[dapepper9]

What plugs did you use? Do your wires cross? Brass cap and rotor?

 

[amanda2des]

I believe I used auto lite plugs, that or acdelco, I don't remember now. I got the cap and button as a pair at Orileys, they were the better set of the two options they had. And exactly what do you mean about wires crossed?

 

[jsmith]

Route your wires like this-
TSB 18-48-98

 

[dapepper9]

^^this explains the wires. Pull a plug or check your receipt and get the part number. ONLY COPPER PLUGS should be used. Champions are what came factory but many like these:
NGK BKR6E
Bosch 7962
AutoLite 3923

Were old plugs oily at all? Plenum gasket is probably a factor as well

 

[amanda2des]

Plug from the number 1 cylinder had some oil, all the rest were good just old. I used the computer in the store that tells you what plugs to get, but I'll check when I get home Friday to see exactly what I have in there.

 

[amanda2des]

I am certain I did not pay near that much attention to detail when routing the wires. This was the first time I had tackled such a project without my brother or father around. I'll definitely try to sort that out and see if it helps..

 

[Yeret]

Consider checking the Idle Air Control valve (IAC). I've pulled 2 of them between the 5.9 in my truck and the 5.2 in my mom's Jeep and they were extremely dirty. My mom's Jeep in particular would have random stalling issues at idle that were eliminated with a new IAC.

And definitely look at the TSB that jsmith posted. I had nagging misfire issues that were (mostly, see below) alleviated by following that.

I've learned that these Magnum engines are notorious for blowing out the intake plenum gasket (stupid 2-piece aluminum + steel design) and when it goes, the engine becomes an oil lamp. My engine was going through a half-quart of oil a week because of it. A full set of spark plugs never made it a full year before they would start misfiring due to fouling.

 

[amanda2des]

Sorry for the delay. So after multiple work sessions I found a few problems which collectivly resolved the issue. I found a broken PCV valve, replaced, found out I didnt know the proper use of di-electric grease, kicked myself and corrected, installed the recomeneded Champion spark plugs, and rerouted the plug wires. The truck now runs as it should, and I learned a lot about it in the process. I appreciate everyones help, now onto the next phase!