97 5.9l

Truck idles roughly after a few minutes. Acts like its going to die, catches itself and revs up, then repeats. It was misfiring going down the road recently as well.

Turned out the spark plug for cylinder 5 was toast as well as the spark plug wire. I replaced it and it no longer misfires going down the road, but still idles roughly. Only that plug looked even dirty the rest were fine.

no engine codes, it was giving p0305 before when it was misfiring going down the road. That went away with new plug.

I replaced evap canister and carbon canister in the hopes bad idle has something to do with that. Opening gas lid/ unhooking evap line under hood seems to have no effect on how it idles down and up.

I notice that my air intake, the plastic that seals over the plenum with a worm clamp- is cracked on the lip that goes over the plenum. Could it be that crack is fouling up the air mixture?

Thanks. Just seems like the misfire and the bad idle are related- could be wrong. Trying to find the source of the issue

 

The filter housing is unlikely to be your problem. Maybe a vacuum leak somewhere... How old is the distributor cap/rotor?

 

I'm not sure. You would suggest replacing the cap and rotor?
I probably don't have to replace the entire distributor? I have never replaced anything on the distributor before so bare with me.

Looks like its pretty cheap for the cap and rotor. I don't know much about it- but they sell 'tuning kits' for about the same price. Is that just a better rotor/ spark plug wires? https://www.rockauto.com/en/catalog/...une-up+kit,684

 

Not sure about quality on those....... I usually just go to the local parts store, and see what they have. Might spend a little more, but, I get better quality parts, and if there is a problem, they are right there. Not three-day shipping away.

 

Did you replace one plug or all of them?

 

Just the one plug and wire.

 

If one was bad who knows what condition the rest are in.

 

Hello

I had the same problem with my 1995 ram 1500 gas 5.9 and I did all of the sparks plugs and cap rotor and replaced all of the vacuum line and everything worked out very well. But I still have an engine vibration so I am now replacing the harmonic balancer and all of the pulleys as well.

But good luck hopes it works out for you.

 

Thanks. I'll take your advice. Where did you get your rotor/cap and lines? I've always thought rockauto was superior to the likes of autozone/advance auto parts but heyyou has me second guessing myself.

 

I get mine from Rockauto but never checked with the part stores. My logic is this. If the part is less then $15 more at the parts store I go with them, for the reason HeyYou mentioned. If it's above $15 more I go with RockAuto