Greetings Ya'll,

I'm a new member & have been researching through the forum all that i can about my situation with my 2000 Ram 2500 Cargo Van (318 V8 CID EFI).

I went to do the "Right Thing" & also installed plugs, rotor button, cap, wires, & even added a can of Seafoam to the gas tank, & since then it has been idling High & Low, making whooshing noises, bogging down in low range speed, back firing, & even acting as if the motor was going to lock up.
To really confuse the matter, ... Not all of these symptoms present their selves at the same time, & to further compound the problem, after having used carburetor cleaner on the throttle body (Without taking it apart), the Van will idle fine in park & it can be revved up in Park, Drive, & Reverse without bogging down. I can drive it roughly 3 miles (to the store), have it off for approx. 15 minutes, & then start it up, & immediately in a 35 MPH zone the problems come back. But, when I reach the 45 MPH zone, & can give it more gas, then it begins to run much better.
I'm going to pull the Idle Air Control & clean it, ck the wires for being properly placed & connected, ck cap, button, etc. I've also been going through the Haynes manual, & it is a "Lil' helpful" cuz it gets you to thinking that it's all about "Your Vehicle", till you realize that it also is talking about 3 to 4 other configurations of motor. Which leads me to ask, .... is there in this group data available that is specific to my motor, or, do Ya'll know where that can be obtained.

With Great Respect.

 

Try unplugging the front O2 sensor, and see if some of your issues go away.

Does the engine idle smooth in park?

 

Greetings HeyYou, I will try that. As far as idling "smooth" in park? The conditions are erratic, they occur, & then they disappear, then they come back with a vengeance, then one or more disappears. That's why I Titled my first post "Possessed Work Van", Lol! Initially, the problems did occur in Park, but after I sprayed out the throttle body without taking it apart, they then began occurring in low range driving, yet they'd disappear at speeds above 45MPH.SMH Today, I'm going to dismount, Ck/Clean the various controls at the throttle body, & I'll also ck the o2 sensor. I also need to say, that from a Cold Start, after all that I've done, there are no "obvious" problems, .... But, after driving the Van approx. 4 miles, the problems resurface. Again, Thank you for the tip HeyYou!

 

sounds like it happens after it goes into closed-loop mode...

 

That sounds a lot like a failing O2 sensor.

Did you route your plug wires according to the TSB? (its in the faq section here.)

 

dbbd1, Thanks for replying, ... But what is a "closed-loop mode"? ..................... HeyYou, When I installed the new wires/plugs, I pulled out the old, & replaced with new, one by one, just as if I were replacing an Ice machine, Heat pump, Condensing gas furnace, or circuit within a Breaker Panel, that I was unfamiliar with. My Trade is HVAC/ Refrigeration/ Electrical, & I long ago learned that only a Fool charges in like Custer at the Little Big Horn, without first evaluating the situation. What was there originally, I replaced with New, in the same manner that it had existed in. Of course, someone that had worked on the motor before me, may not have followed Standard Automotive Practices. I did run the wires in their Factory Supports etc. As far as TSB, I'm not familiar with that. As far as the Oxygen sensor, I agree that it's possible, for going through the Haynes Manual, there are symptoms that cross-over to many different parts, including the O2 sensor.

 

Closed loop happens when the PCM starts paying attention to the O2 sensor for dispensing fuel. Disconnecting the front O2 sensor prevents closed loop, and the PCM runs the engine from tables stored in memory. (open loop)

if it runs better with the sensor unplugged, simply replace the sensor. (reset the pcm as well.) if it runs the same/worse, well, that's not the problem...... if you have a lotta miles on the truck, and the sensors are original, wouldn't hurt to change it, just as a maintenance thing.

O2 sensors have a fair few failure modes that won't set a code.......

 

HeyYou, Thanks for replying. I found in the Haynes book, that "open loop" is for the motor when it is cold, & then warms up to 600 degrees, Chapt. 4A-20 under "oxygen Sensor". I also found the OHM values for the "heater" for the O2 sensor (5 to 7 Ohms), as well as voltage out puts >>> Haynes book Chapt. 6 page 32 Chapter 14 #2-5 speaks of it's operation, but it states that the SMEC/PCM "operates in the open loop mode when there is a problem with the O2 sensor". If I'm understanding you correctly, my van could be operating as if it has a "cold motor", even though the motor has achieved the 600 degrees? Another question, to reset the PCM,... Doesn't that have to be done with a scanner? HeyYou, help is greatly Appreciated!

 

To reset the pcm, just disconnect the battery for 15 minutes or so. It forgets everything it knew.

The PCM has to realize there is a problem with the sensor, before it will set a code. Trouble is, the sensor has various failure modes that WON'T set a code, so, the PCM thinks everything is just hunky-dory, and pays attention to a sensor that is flat out lying to it. So you end up running really lean, or rich.... and the PCM doesn't figger it out...... So, the unplug it, and run it test will let ya know if the sensor is indeed bad. (and, will also most certainly set a code.....) If the engine runs great for a couple minutes on a stone cold start, and then starts screwing up, that is a sure sign of a failing O2 sensor.

 

Thanks Hey You! That sounds like the "Intelligent" Thermostats that Customers sometimes have me install, & the Processor boards on other HVAC/ Refrig. Equipment, cuz' some of them will display a "Fault Code", until you clear it by cutting the power for about ten minutes.

At first I was thinking that I'd have to get the Van to a Dodge Dealer, & pay $$$$$ to get a new program/ software installed.

Again, Thank You Sir!