I have a 97 ram 1500 with a 5.2 with 214,400 miles. I did the plenum repair and i've noticed the idle is around 500-600 rpm. i don't know if this is normal. anyways my issue is that when its in neutral and its reved up a little bit the rpm drops rapidly and almost stalls. The needle drops to the last mark before "0". The lights dim like the truck is going to shut off, but then the rpm goes back to idle (5-600) This when its revved up to about 1500-2K, I didn't try but i'm sure if i reved it up more it'd just die.

has anyone else had this problem and what fixed it? Its not that its a huge deal right now cause i don't sit around and rev my truck up, i just noticed this by accident. I figure i can try to do some preventive maintainance now so it won't fail on me down the road.

 

Sounds like you're describing a bad IAC sensor. How long has it been since you've cleaned the TB...especially the IAC port and the tip of the IAC sensor?

 

Mine did the same thing last week I replaced the IAC and its better now.You could try cleaning your IAC if you dont want to buy a new one.

 

Yea, try cleaning it first https://dodgeforum.com/forum/dodge-r...n-the-iac.html And you did have the negative battery cable off when you did the plenum right? Also remove the cable if you clean or replace the IAC.

 

yes i removed the negative battery cable and i'll try this. I know the sensor inbetween the alternator/ac compressor and the coolant outlet hose is cracked on the top. I'm not sure which sensor this is though

 

Engine Coolant Temp sensor I believe. Does the temp gauge work fine?

 

+1 on coolant temp sensor - would not cause the idle issue (+1 on IAC) I don't believe, but will surely throw a code if it is more than a crack in the plastic housing I would think. I would advise replacing it anyway to prevent problem. PCM uses temp to compensate for air/fuel mixture I believe.

 

Check codes for sure. http://dodgeram.info/Engine-Gas/OBDI/pcm_fault_code.htm

 

my temp guage works fine and i forgot to mention that I tested the ECT sensor and it tested out fine. I tested it with an ohm meter at various temps and with an osilliscope. (and no CEL) I know the TB was cleaned at 105,000 miles but it probably needs it again since i'm now at 214,000+.

 

With lights dimming as it trying to die, I suspect something else is the problem.

When the TB was cleaned, did you do it or someone else? Was IAC removed and cleaned at that time, and how long ago was that done? Has it been running right since then until now?

If IAC pintle was turned or pushied in or out, it would have been damaged and needs repplaced. I suspect with the lights dimming issue, there is a bad or loose ground. Check negative cable at both ends. make sure cable isn't breaking down at connector under insulation. Clean connection at both ends.