Hey all,

Truck: 1997 Ram 1500 Single cab sport w/ a 5.2
Replaced parts:

• IACV (I've replaced this twice thinking I may have gotten a faulty part the first time.) Cleaned the seating area of the valve as well
• TPS
• Cap/rotor/wires/plugs
• Replaced the small rubber vacume hose that comes out of the front of the throttle body on the passenger side of the truck.

Symptoms:
The truck runs well and starts up fine. It does not die when the motor is below operating temp. As soon as the truck warms up the idle will drop while at a stop. The truck basically idles lower until it idles so low that it quits running. In order to drive it I have to do a little two foot action when coming to a stop.

I've read that is might be a crank sensor, any other thoughts?

Oliver

 

Have any codes? It could be a number of things. I know these trucks only like Mopar sensors. So your TPS and IAC could not be working properly (at least to the computer) causing it to die. Vacuum leaks, crank sensor, PCM are just a few others.

 

Might be O2 sensors as well. Could try unplugging the front O2, and see if the problems go away.

Also, did you reset the PCM after you changed the IAC motor??

 

Hey everyone:
1) I have not reset the PCM - I assumed disconnecting the battery would do that.
2) I will check the codes tonight and see what pop. Honestly, my old 5.9 had a similar issue and it was the IAC, so I just figured I'd change that out and it'd be fixed... I was wrong.
3) That's a good idea on the O2 sensor, I'll give that a try on the way to get the truck scanned for codes.


I will report back later this evening.
Oliver

 

Just disconnecting the battery isn't enough, unless you leave it disconnected for several hours. Process I use is: Disconnect battery, turn on headlights, count to ten, turn off headlights, reconnect battery, turn ignition to "On" (not start), count to ten, (don't touch ANYTHING) start the truck. It should figure out idle fairly quick.

 

It's wise to use a mopar IAC it's hit or miss with the aftermarket ones. Also how old is the battery? Might want to have it load tested. A weak battery can start the truck fine and cause it to fall on it's face when running.

 

Under the heading of have ya tried this yet?!? I had that exact same problem, as I'm sure many 2nd gener's have had. I discovered with 'ol blue (96 1500/5.2) the intake air temp sensor was coated with oil. Twas due to the chastity of the keggar oil leak. My autel noticed that the IAT seemed...off. I cleaned the IAT with some brake cleaner n voila, she once again ran according to factory spec.

 

Hey everyone,

Thanks for all of these ideas! Last night I tried resetting the PCM and no change. It did take her on a nice drive down to the Home Depot via a little two foot driving and she ran great other than diving at stops. It's such a bummer because the truck runs and shifts so smooth it just needs this stalling issue fixed.

Today I'm going to scan for codes and try disconnecting the O2 sensor.

Will report back here!

Oliver

 

I bet it's the IAC

 

Update:

This morning I scanned the truck for codes and it had none. The strong smell of gas continued after shutdown. This strong smell is what started leading me to believe there was a fuel delivery issue and the truck was running rich.

I then took the truck back home and unplugged the O2 sensor at the first connection above the transmission. Based on my wire tracing, it appears that this clip will disconnect both O2 sensors.

Results: The truck is now running and not stalling at a stop! Obviously the check engine light is now on, but the truck no longer stalls and I believe I've identified my issue. I'm fairly certain the faulty O2 is the one nearest the cat, so I will be replacing that sensor with one from Rock Auto (NTK). https://www.rockauto.com/en/moreinfo...Bqsmq%2Fx5U%2F