Whats up everyone, hows it goin. Im brand new here, first post..... I have a 1998 1500 5.2L with 150k. I just bought this truck 4 months ago, and it runs great. I recently started having a problem with rough idle and stalling, immediately after starting and also while driving. It only stalls when my foot is not on the gas. I did the key flicker code thing, and it isnt throwing up any code. I took out and checked the IAC, and it was clean, I dont have tools to do much else.

In the title I said NOT CATCHING, and this is why, maybe this will pinpoint it for some of you out there. Before this started happening, when I would accelerate then completey let off the gas, the rpm needle would always swing down and slow to exactly where it idles at normally. Since this all started happening, I've noticed that the needle wont catch at the normal idle anymore. Now when I completely let off the gas, it will swing down to 500, 400 sometimes 300, catch there, then slowly work its way back up to idle. Sometimes it wont even catch, it will just swing all the way down and stall. That seems like a pretty distinct problem, anyone know whats up?

Thanks so much
Nick

 

CPS?

plenum gasket gone? (look into the TB if you see oil its shot)

Clogged Cat?

Fuel Pump Starting to let go?




sorry i couldnt be more help

 

Just because the IAC is clean, does not mean it's working. If you want to try a new one (don't buy a cheap one from AZ or wherever) remove the TB and all the sensors on it and clean it. While it's off use a flashlight and mirror to look around inside the intake manifold and see if you have any oil pooling in the corners or anywhere.If there is oil in there the plenum gasket is blown, and chances are good the front o2 sensor and the cat are also no good or not too far behind.

 

where is the plenum gasket on these trucks?

 

Bolted to the underside of the intake manifold.

 

its not a hard job at all if you have basic mechanical knowledge, torque sequences and specs (aka Haynes or chilton repair manual)

 

...funny you mention "basic mechanical knowledge" 95RAM, because Im currently attending Marine Mechanics Institued in Orlando, so it took some courage to throw this question up, lol. Thanks for all the replies guys, im gonna check out all of those. Also my buddy in my class has a new diagnostics brick in the mail already, we're gonna hook it up on tuesday and see whats up, hopefully.....thanks again

Nick