So, I posted on here a while ago because I had my transmission leak and replaced the oil pump bushing and seal. All fixed. But now I have other issues. Lol. So I thought I was having torque converter issues. The truck would occasionally surge as I am coming to a stop (like 0-10mph, and under 1000rpm) and when I'm idling. When I say surge I mean the RPMs will drop to like 100-300 rpm and then raise back up or die. It just depends on what it feels like doing. It surges more than it dies though. And it will also do it in park. So I've kinda eliminated anything trans related. But here is some background information. I don't know if it will help or not.
1.) the 4x4 does not engage. It's at the diff from what it seems, not at the transfer case. I believe this is just coincidence.
2.) only replaced torque converter and oil pump seals and bushings.
3.) the crank sensor wires were smashed as I threw the trans back in. No biggie. Had an old spare sitting in my glove box. Lol so I don't believe it's that.
4.) check engine light is on, P0171, but I have an exhaust leak between my header and collector flange before the o2 sensor. I believe this is where this code comes from. JUST HAPPENED THIS MORNING.
5.) when I'm in overdrive is where it gets weird. For some odd reason, if I hammer it down in OD, the truck starts to bog. Like it's missing. But it doesn't really feel like a miss. I don't know how to explain the way it feels. But I recently tuned up the truck a year ago. So my basic items should be fine.

So with all of this in mind, what do you guys think this surging and idling issues can be? I believe it's engine related. But she runs great besides just the issue I'm describing. I'm scratching my head here. Anything helps.

 

First thought is that I would check the IAC and clean the throttle body. Then moving on to the TPS.

 

I was thinking IAC also but it's also fairly new. I bought it under a year ago. Also the TPS and cleaned the throttle body. Lol. I try to keep up with my truck as much as I can. It might make sense to be the IAC possibly. Because now that I think about it, I started my truck one night after work, and was idling at about 2k. I unplugged IAC tried disconnecting the battery turning off the truck and the only thing that fixed it, was unplugging the PCM for about 30 seconds. Haven't had a problem since. That might not be a bad place to start.

 

What brand IAC? Our trucks REALLY dislike aftermarket parts in critical locations..... I had the same problem with my "new" IAC, replaced it with an old mopar unit from another motor I had, and the problems went away......

 

It was one from orielys. I don't remember if it was the cheaper one or the expensive one. Normally i go with the good parts. You think it's just a coincidence that's it doing it now after I get the trans put back in it again? I can try replacing it. My dad has an 01 5.9 sitting in his backyard waiting for a motor. I could just swap them for a few days and see what happens. I know some parts changed on those engines though so I don't know if it will work. I imagine it will. And what other parts do you think are pretty picky about being aftermarket?

 

What did you do with the crank sensor when you were removing/installing the trans? If left in place, they tend to suffer from that experience.......

 

Well the sensor was was fine it was the wire that I nicked up. I had a stock one laying around and I put it in and it was fine. I was getting an intermittent crank signal loss code. That's why I put the stock one in and it went away. So I don't think it's the crank sensor.

 

Doesn't that code also reference cam sensor?

 

Yeah cam/crank signal intermittent. But the new crank sensor fixed it.

 

UPDATE: Threw in an OEM IAC in from my dads blown 5.9. Problem still persists. So that's not it.