91 3.9L 5 speed
did plugs , wires , cap , rotor , pcv , air filter
will run fine for about 8-10 miles then sometimes when coming to stop will drop to 2-400 rpms , start missing
& wants to stall out & get a stank from exhaust .
any ideas?

 

Does it give you any codes? You could also read through this.
From what I have read, and you saying "then sometimes when coming to stop...," it could be the Idle Air Control (IAC) motor (mounted on the back of the throttle body; NAPA's website calls it the Idle Air Control valve.)
First, check for codes. If you get any, post the codes you get (you can fix them as well, when removing a sensor, disconnect the battery before you remove the sensor [this also allows the computer time to reset, clearing stored trouble codes, you should leave the battery disconnected about 5-10 minutes])
Did you have this problem before the tune-up? Are there any variables this occurs under (full tank of gas, half tank of gas, certain speeds decelerating from [or certain deceleration type ie. just coasting, slight braking, hard braking])
You may also try using some throttle body cleaner, and see if that helps at all.
Post back with more info!

 

Glad to see someone else uses allpar. I was beginning to think I was the only one.

 

i have 1994 ram 1500 3.9 2 wheel .... i have sort of the same prob, when engine is cold and i start it,it runs fine except a chugging around 30mph... but when warms up all hell breaks loose it stalls rough shifting top speed around 25. i changed the air charge sensor and the coolant temp sensor checked the throttle position sensor with a volt meter checked out ok changed plugs and cap and rotor map sensorlooks good, checked EGR, and check o2 sensor, new air filter.... seems that the engine is either dumping too much gas or starving for fuel.....just wonder how much of a problem the idle air control valve will create ..i pulled it out looked , it had some carbon but i cleaned it up ..when i give some gas and let off the idle drops low then chuggs abit then stables out ... but driving is almost impossible.....thanx for any help

 

Clean out your throttle body.

 

I am having the EXACT same problem, only after about 3 mins of driving, after 10 mins of bogging, everything is fine.

 

anone with any help in this issue? the truck runs great for the first little bit after an overnight park, but gets worse afterwards.

would a clogged Cat do this?

 

Yes, a clogged cat will most certainly do that. Basic symptoms of a cat screw-up are as follows:
Erratic Idle, random misfiring of cylinders, heavy gas smell in exhaust (from comp trying to adjust fuel), stalling erratically, major power loss, and eventually it won't be driveable. Take it to an exhaust shop and have it checked, or you can check it in the dark, run the truck for at least ten minutes and see if it glows. If it does, it's definitely screwed up.

 

It was IAC
cleaned it up & sprayed the crap outta it with throttle body cleaner
been fine for awhile now
thanx for the input

 

catalic converter plugs up it will stall