Well I was back and forth and almost made a deal with simplysmn to get a 1st gen crew cab conversion but ended up with too much happening with our one son...and then suddenly (yeah sure) found a good deal on a 3rd gen. which (my wife liked) suited our needs.

So...2003 3500 SRW 2WD auto....148K on the odo.

It is doing this about 50% of the time:

Crank truck...it will idle for a second then bog to 500 RPM and immediately surge to ~1000.

SOmetimes it does it once...sometimes multiple times (as it it doesn't stop on its own)...but revving it up a couple times fixes it.

It also does this (again about 50% of the time) when I come to a stop...truck is in gear and it starts to do it...put it in neutral and rev it up a couple times (not crazy...just to 1500 or so) and it idles fine.

Truck has no other symptoms...when it idles normal it seems great. Truck has plenty of power , goes down the road fine at all speeds and is getting reasonable fuel mileage.

Truck seems sound (once I changed the fuel filter that appeared to have 50K miles on it) other than this.

Any ideas? Leaning towards TPS...?

 

Not knowing the history of the truck the first thing I would change is the FCA (Fuel Control Actuator). One of the symptoms of the FCA acting up is a loping idle.

 

X2 on the FCA as above

 

Ordered one (and a spare lift pump).

Thanks!

Now here's to hoping I can get the torx bolts out without killing them.

 

Mine was doing this 2 months ago, I was told it was the tps, also knows as the APPS. I ordered one and it quit doing the problem when the tps showed up, and being busy at work I didn't get it changed. 2 weeks ago, it did it again leaving a stop sign, and then it did nothing. Towed it into the local *********** and I have no trans pressure, something went out. Towed it to the local diesel guru, and they aren't sure if the problems were related, but all I know is I have a new tranny on order. Just a heads up incase either of those previous suggestions don't work.

 

Knock on wood and fingers crossed...replacing my FCA fixed mine.

I'm on day 2. I did not even realize the truck was growling at me before as well as the other symptoms I listed.

No more growling, no more weird idle at any time.

Not sure if it helped or not but I read some of the stories on having issues getting the T-25 torx bolts out.

the 2 days before my FCA got here I WD-40'd the bolts and tapped on them with an socket extension. The day before they got here I popped my hood the second I got home from work...waited the time it too for me to be able to touch things without getting burned and then loosened the bolts...everything was still very warm but not so much that I burned myself. They all came out with relative ease. So I;m not sure which step...if not all of them helped but the actual job took me about 20 minutes start to finish.

 

Good to hear!