Having a look at all the ignition parts really wouldn't be a bad idea. See what kind of shape they are in, and what kind of plugs are in there. These trucks really don't care for the rare-earth plugs...... end up with mystery misfires.

Pull a couple, and have a look, see what you find.

 

X2! See if your cap has brass or aluminum inserts in it. The aluminum ones corrode in no time.

 

Changed all the spark plugs, took the airbox off and the check engine light went away and it seemed to run better. Took it on a drive (Put the airbox back on first) and it was there at first but went away slowly. Only thing is the idle should probably be raised? If I let it sit for a minute or slow down to go around a sharp corner it'll go down to about 400 rpm, sounds like it wants to die until I give it a little gas. When it did have the sputtering problem while driving, it went away if I hit the gas a little harder and got over 2k. Nothing compared to when this occurred on the highway and when I was getting it home. Could the IAC(?) need cleaned or possibly replaced? I know on my last gas truck I could bump the idle up with a special tool, should I just do that?

 

Pull the throttle body, and give it a thorough cleaning first, especially the IAC well, see if that doesn't resolve the issue.

 

Cleaned it all off as much as I could, the IAC looks fresh and new. Started up but it still kept creeping down in rpm just sitting in park. Weird thing is that with the air box on it has a check engine light but without the box the light goes away.

Anyway, when I gave it a little gas there was a hissing sound and I thought maybe it’s a vacuum leak. I couldn’t find any leaks in the lines or anything. Although there was some Gunked up oil in the lines, is it possible the plenum would have anything to do with this or pcv valve? Maybe cloggy injectors could be another issue?

Thank you.

 

If it's an aftermarket IAC, I would replace it with a genuine mopar unit.

Did you actually remove the IAC valve when you cleaned the throttle body??

May wanna look down the throttle bores, and see if there is oil pooling in there.....

 

I did not remove the iac, don’t have the right tool for it right now. There is some oil down there, none in a pool, just dried out on the bottom it looks like. I didn’t see a mopar logo on the IAC itself just a part number.
Should I take the IAC out and clean the tip of that too? See if that does anything then try an official mopar one?

 

Take it out and wipe it off, and blow out the well it goes in as good as you can too. Don't move the pintle on the IAC, just wipe it lightly. Shouldn't be any crusty stuff on it.....

Leave the battery disconnected while you are workin' on it. When you are done, and have it all put back together, turn the key to On, count to ten, THEN start the truck. Gives the PCM time to learn the 'zero' value of several sensors.

 

The truck came with an extra distributor cap and the sensor underneath it, when I went to replace both of those I noticed that the wires on the sensor were exposed and almost pinched through. I put it all back together and went to start the truck and now it won’t start unless I give it gas. It won’t hold an idle at all. The IAC plug won’t stay in there either, it doesn’t click onto it at all. I’m thinking about just going to get a new IAC.

I had a neighbor come out with a timing light tool, it’s getting spark to all cylinders.

Im about to go out and pull the TB off again to change that IAC out, but another thing to note, the TB Gasket was cracked in half, last time I just kinda jimmied it back into place. I’ll replace that too but would that contribute too?

Thank you

 

A vacuum leak (broken gasket) won't help.

Get a genuine mopar IAC, they are a LOT less problematic than the aftermarket fellers. (yes, voice of experience.....)