HELP!!! 99 Ram 1500

[kr1spaterson]

Hey all,

I need some serious help. I have searched around the pages and have foundno answers. When I start my truck, it will idle fine but when it gets to closed loop status, it fluctuates idle and then dies. Then it will start up when cold. The following is what ive replaced.

- brand new engine
- fuel pump and checked pressures
- PCM
- both o2 sensors
- IAC, TPS, MAP, CPS

What can this be? I am stumbled at his point...thanks for any help!

99 Ram 1500 5.9L

 

[jsmith]

Did you use MOPAR tps? I had same problem and changed tps(that I had just replaced) to a MOPAR one and it fixed it

 

[dapepper9]

Also what brand o2s? Did you ever reset the pcm?

 

[kr1spaterson]

I am using all mopar parts, and the PCM has also been reset.

 

[kr1spaterson]

What stumbles me is that when it goes to closed loop, it wants to bog down to idle at about 350rpm, then eventually dies. The o2 sensors are NTK.

 

[dudeman2009]

What stumbles me is that when it goes to closed loop, it wants to bog down to idle at about 350rpm, then eventually dies. The o2 sensors are NTK.

Its reading something that is causing one of two things, low air flow to the engine, or strange fuel flow to the engine. Either way, something is making the PCM angry. If you have access to a scantool you can make your life a little easier by looking at both the fuel trim and O2 readings, as well as checking to see what your tps is reading. You may also be throwing a code that doesnt set off the ses light.