QuestionQUESTION: I Have A 2001 Ram Van 1500 With A 3.9 & Auto Trans. My Problem Is While Driving, The Van Will Stumble & Act Like It's Going To Die. It Feels Like A Misfire On Several Cylinders & Loses Power & Backfires Through The Throttle Body. Fuel Pressure Is Good While This Happens & It Isn't Setting Any Misfire Codes (Or Any Codes For That Matter) I Can Shut The Vehicle Off & Start It Right Back Up & It Will Run Fine. So Far I Have Replaced The TPS (Do To A Forum I Read) Replaced The Coil/Wires & Plugs. I Took It Into A Repair Facility & They Couldn't Really Figure It Out Either So Started "Throwing" Parts At It. They Replaced The Hall Effect In The Distributor & It Cleared Up For About 5 Days Then Started Acting Up Again. The Owner Of The Facility Said He Read A Bulletin About The 5 Pin Neutral/Safety Switch Leaking & Shorting The Ignition To Ground Causing A Similar Condition, So I Replaced That Also... It Is Still Stumbling & Falling On It's Face. I'm A State Certified Technician Myself & Can't Figure It Out & Neither Has Anyone Else I've Had Involved. None Of My Connections Are Corroded Or Can Find Any Chaffed Or Broken Wires..Any Help Would Be Greatly Appreciated!!! Thanks... Paul
ANSWER: Hi Paul,
I am surprised that you have no fault codes at all. Could the fault code readout or PCM not be doing the fault code readout function?
About the only type of device that causes what you describe and without producing a fault code is a faulty exhaust gas recirculation valve. However I don't have a Ram Van manual for '01 so I don't know if your 3.9 has an EGR valve. The 3.9 in the Ram truck appears to not use an EGR in '01. An EGR can cause this when the valve gets gummed up and fails to close tightly upon slowing down or accelerating, and generally not produce a fault code.
Let me know if you find an EGR on your engine.
Roland
---------- FOLLOW-UP ----------
QUESTION: There Is No EGR Valve, But Yes, It Does Feel Like Similar Symptoms. The PCM Is Displaying Codes Which I Had A Gas Cap Code & O2 Sensor Code Which I Replaced The Gas Cap & Cleared The Exsisting Codes. The Facility I Took The Vehicle To Also Tried A Bell Housing Crank Sensor To No Evail. As I Stated, This Is An Intermittent Problem, But Happens Daily. Once I Shut The Vehicle Off & Re Start It, It Runs Fine. When The Symptom Does Occur, The Scanner Shows An Erratic Ignition Output. Could This Possibly Be A PCM Intermittently Failing? (Seeing It's Not Giving Any Codes)
ANSWER: There is a code for a faulty PCM so absent that I would not change that out. One thing I notice in the '01 manual is that although the distributor is acting only as a cam shaft position sensor it is apparently important that it be properly positioned. This involves use of a diagnostic readout box. If you don't have the pages I can copy them and attach to an email. If you want them tell me your email address but don't use the @ symbol instead us "at".
The history of the 5 days OK function after replacing the sensor in the distributor makes me wonder if that might be involved.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hello Again Roland. My Van Finally Through A Code Last Night. I Have A P0442 Evap Code. Like I Said, I Replaced The Fuel Cap Already. Under The Code For An Evap List It Also Lists Possible Failures Including Evap Canister or Hose Cracked, or Not Connected.. Purge or Vent Solenoid Defective... Or A Vacuum Leak At Engine... I Checked The Engine Hoses And Everything Seems To Be Connected There With No Cracked Or Rotted Vacuum Lines. Would A Canister or Purge Solenoid Cause The Symptoms I Am Experiencing? I Could Also Smell Fuel Around The Canister...
Paul
AnswerHi Paul,
Certainly smelling fuel around the canister implicates the canister/purge solenoid as the cause of the 0442 and also that fuel vapor leak would be a candidate for the reason for your problem as it would cause an issue with the fuel/air mixture. So inspect that part of the system to find the leak. Let me know how it works out. It is good that you now have a clue.
Roland
