I've got a 5.2L and over the last month the idle seems to be on the fritz. I drive it for about 30 or so miles and its fine then the throttle or idle tends to stick between 2000 and 2500 rpm's. This morning though as I was leaving out for work the truck started and was idling at below 100 rpms and when I gave it gas figuring it was just cold after I took my foot off it cuts off entirely. Now it will start but wont continue running. I checked the computer and it is not throwing a code so I really dont know where to start in diagnosing this issue.
I was thinking new plugs and wires but then again its not skipping, its idleing too high and now not at all. I tried to put it in gear to take it to the dealership and as soon as I take my foot off the accelerator the engine dies.

Any ideas? I'd prefer to have somewhere for them to start rather than having my truck for 3 weeks while they gracefully diagnose everything from top to bottom.

Thanks!

-Mark

 

you could do a lot of detailed testing as described in this thread.
https://dodgeforum.com/forum/2nd-gen...ml#post1607475

or, you can go to your local parts store and buy a new throttle position sensor (TPS) and idle air control (IAC) for about $45-50 each. change the TPS first because it can not only cause idle problems but it also causes the truck not to hold speed on cruise control, and also because its the easiest one to reach. if that doesn't fix it, then replace IAC, and check that the well in the back of the TB is clean. keep your old parts as one of them is likely still good. also, not a bad idea to keep an extra new part, as idle problems seem to reoccur. some will advocate cleaning the old ones, i say screw that, just replace them.

 

had same problem change tps and iac but it ended up being the o2 sensors being fouled out and sending the pcm inacurate readings making my engine die and idle being very eratic espeically if a lil water got them wet they went crazy

 

Sweet! Thanks for the quick responses. Ill mention all 3 to the service writer monday morning and hopefully one of the three will be the relying problem.
Thank you!

 

I just went through a somewhat similiar problem...my truck wasn't dying out completely though. It just lost almost all power. Check engine light came on, the code translated to multi-piston firing errors. New plugs, wires, distributor cap, rotor button took care of it.

It was due a full tuneup, so I bought the parts and did this one night in the garage. After this, the truck ran great for 2 days, then started losing the power again...but it just felt different, this time, as the engine rattled a lot...I removed the upstream O2 sensor and the truck immediately idled better. Turned out, my catalytic converter was clogged. I had this replaced with a less-restrictive aftermarket converter, now it's running great and check engine light went out.

Just a thought. I have heard that the Fuel Pump will not throw a code, may check the fuel pressure.