Odd Problem. Dodge techs come in.
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Record Breaker
Joined: Nov 2003
Posts: 1,256
Likes: 2
From: North Charleston, SC
If it happens in the first mile or so it is NOT the O2 sensor. O2 sensors are only monitored by the PCM in closed loop operation after the engine reaches operating temp.
My money is on the fuel pump. Specifically, there is probably a clog in the pump and when you idle, you're dribbling gas into the engine. The moment you step on it, you're pushing the pump and the clog restricts it.
There should be a schrader valve (same type of valve as on you tires for air, but a different size,) on the fuel rail somewhere, covered with a screw on cap. I have never seen a truck without one, but I have heard that a few model years did not have them.
The only other things I can think of that might cause you problem (other than the PCM) is a faulty EGR valve or clogged catalytic converter. A clogged cat typically throws random misfire codes and makes the engine feel like its pulling way more weight than it should.
My money is on the fuel pump. Specifically, there is probably a clog in the pump and when you idle, you're dribbling gas into the engine. The moment you step on it, you're pushing the pump and the clog restricts it.
There should be a schrader valve (same type of valve as on you tires for air, but a different size,) on the fuel rail somewhere, covered with a screw on cap. I have never seen a truck without one, but I have heard that a few model years did not have them.
The only other things I can think of that might cause you problem (other than the PCM) is a faulty EGR valve or clogged catalytic converter. A clogged cat typically throws random misfire codes and makes the engine feel like its pulling way more weight than it should.
Definitely not a clogged cat. Ive been through a few of those on different cars. Could be the EGR but that really has no bearing on fuel adaptives. My father still wants to replace the PCM, he is sure that it is the problem. Im still trying to diagnose it.
Record Breaker
Joined: Jul 2007
Posts: 1,488
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From:
I've seen bad fuel pumps cause this exact problem. Sometimes you get a tricky one that is starting to seize and sometimes it runs fine then without warning it will bind up and the fuel pressure will drop but not enough to stall the engine. Hence the road test with the fuel gauge.
This truck shouldn't have an EGR so you can rule that out.
This truck shouldn't have an EGR so you can rule that out.
Professional
Joined: Oct 2005
Posts: 174
Likes: 0
From: Maine
I hate to say it but I disagree with aim4squirrels...I had a similiar problem. The truck would start right up great BUT about 5 seconds later as it tried to drop its idle it would go right to hell. Ran crappy for a few min sucking air like hell sounding like a vac leak and hitting the gas a few dozen times would finally kind of bring it out of it.
Turned out to be the front O2 sensor.
I switched plugs, wires, cap, and rotor. Ran injector cleaner, Marvel mystery oil and checked for the clogged cat. Finally just switched the FRONT O2 sensor and ran perfect.
Turned out to be the front O2 sensor.
I switched plugs, wires, cap, and rotor. Ran injector cleaner, Marvel mystery oil and checked for the clogged cat. Finally just switched the FRONT O2 sensor and ran perfect.
Legend
Joined: Jul 2007
Posts: 7,843
Likes: 13
From: DFW, Texas
Hey, it's fine to disagree.
I'm speaking merely from book knowledge on what the PCM is supposed to read during open loop, but you've had first hand experience with said problem. I haven't had a front O2 sensor go bad. Posting up first hand knowledge is how we all learn. MonteC stated he disconnected the sensor and it ran better, maybe that is the problem.
I'm speaking merely from book knowledge on what the PCM is supposed to read during open loop, but you've had first hand experience with said problem. I haven't had a front O2 sensor go bad. Posting up first hand knowledge is how we all learn. MonteC stated he disconnected the sensor and it ran better, maybe that is the problem.
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Record Breaker
Joined: Nov 2003
Posts: 1,256
Likes: 2
From: North Charleston, SC
http://www.toolsource.com/fuel-rail-...-p-100146.html
Is this the adapter i need for the "special" '97 fuel rail?
Is this the adapter i need for the "special" '97 fuel rail?
