I had a thread about this issue a few weeks ago and I cannot seem to get this issue fixed. It's really frustrating/pissing me off. Today in GA it was about 70 degrees and sunny. I'm going to a braves game and drive it about 15 minutes to the bank and I pull in and let off the throttle to hit the brakes and the RPM's drop quickly and the truck stalls. I put it in neutral and start the truck back up and it will not start without me giving it throttle, then when it does start it stalls immediately. I start it again and give it some throttle to get her going and this time I leave my foot on the throttle to make it hold idle. After about a minute of holding it I let off and the truck idles perfect. I drive the rest of the way to the game and the truck never stalls again but comes close a few times. The idle was either too low or too high. When I leave the game truck starts up and idles fine. I start driving and the first time I let off the throttle the truck stalls immediately and is hard to get started without throttle. It keeps stalling and I have to hold the throttle and the brake at the same time just to keep it idling. Before I get on the interstate the truck finaly begins to hold idle. But its low and the truck shakes a little while its idling. I slipped the truck into neutral and the idle raised to 800 andd the truck idled like a charm. Put it back in drive and the idle lowered to 400-500 and starts shaking. I am so fed up with this problem. Within the past year I have replaced the following: Distributor cap, plug wires, plugs, TPS sensor, and I have cleaned the IAC Valve (think im gonna go ahead and replace it). I replaced a check valve for wild vents last year and it fixed it for about 6 months and now the wild vents are back bad. If anyone has any idea what this could be please give input. I searched and could not find a single thread with anyone having problems like mine (except my old thread).

 

I would start with a Automatic Idle Speed Motor ( AIS) on the back of the throttle.

 

Seems the IAC is simply bad, cleaning it doesn't always work . Disconnect the negative battery cable before replacing.

 

I was thinking IAC too. Bought one today and will be installing it later today. I'll post an update later on.

 

Just remember that some sensors work better than others.