Idle surge and stall
 

96 ram 1500 2wd sport. After starting the truck and driving for about 5 min the problems start. When i coming to a stop the RPM's drop to about 100RPM's then back to 1000rpm's and then back down and tries to stall, i have to tap the gas to stop if from dieing. But when it does die, its a pain to start back up, i sometimes have to crank for about 45 seconds and pump the gas to start it back up. Now i know i have a vac. leak that has to do with the a/c. but i dont know if that is related. Also the plugs are about 9 months old. Fuel pump and filter are about 15 months old. Any ideas people? Also there does seem to be a SMALL lack of power.

bump, anyone with ANY ideas would be great. i have a haynes book but it does seem to help me narrow down the problem.

the primary control of the idle is the IAC on the back of the throttle body. its about $50 at any local parts store. its a common problem.

the best test is this. if whenever the idle is acting up - if you press the gas pedal a tad to crack open the throttle plate, and the problem goes away, and then you release the gas pedal to close the throttle plate, and the problem returns, then its iac. if thats it, get an smc brand or mopar brand and avoid the cheapo ones. they're nothing but constant failures, even when brand new. some people suggest cleaning them. i think cleaning the throttle body is always a good idea, but i've never had that fix a bad iac.
https://dodgeforum.com/forum/2nd-gen-ram-tech/140607-why-does-the-iac-fail-so-frequently.html

if cracking the throttle open doesn't temporarily correct the problem, then its NOT the iac.

it could also be many other things. tps, o2, fuel pump, etc.

My first response to things like this is to check the O2 sensor. I had all kinds of strange behavior--hard starts, rough idle, coughing and stuttering, backfires, stalling, etc. It was all due to a bad heater circuit on the O2 sensor. A new one for $59 cured all of it (well, until the plug wires started arcing and I had to do the TSP re-route--try that, too).

Is it throwing any codes?

no codes, but today i took off the intake and cleaned the throttle body, i also took out the iac and cleaned the brass? tip and it was CAKED i have to use a screwdriver and scrap off the carbon. and when i put it all together it wouldnt start or hard to stay running, i had to keep the pedal pressed and then slowly release it for it to stay idling by itself. i dont know if i pushed in the iac by mistake and dont know if it would reset itself.

well, i know i have two bad o2 sensors, and my truck runs fine, just really rich. like he said, and you can do this under the hood, by using the butterfly itself. get it started, and as its idling, go under the hood with the intake and all that stuff out and just hold the butterfly open very little. rev it alittle. and act as if you are in the truck, give it some gas, and then let it go back to idle but still hold it open very very little, if it does not do the whole spitting thing, then thats what it is.

how did you check the codes? cause it may have thrown a code but not a big enough one for the check engine or maints req light to come on. if you go to autozone and tell them you want to check your computer for codes. its free. and then they can also clear them for you.

no engine light i mean, i might run up to autozone today and let them scan it. ty

Just replace the IAC and then reset the PCM. The truck may buck for a minute or 2 until the PCM figures out what's going on. My guess is that the IAC went bad and cleaning it won't fix the fact that it won't go in and out anymore. My truck took about 1 month to fully figure out the new IAC.

dhvaughan's the resident expert on IAC related problems. He can destroy one faster than a Chuck Norris roundhouse kick.:D

well here is how the day went, i was gonna get in my truck and go to autozone and check for codes, and i remember i had a dist. cap and rotor and wires in the house, so i figured i change them b4 i head out. so i did all that and BAM!! no more problems, the inside of the cap was all nasty. i guess it might have been a mix of cleaning the TB/IAC and the wires and cap. Thank u everyone for the help!!