I've been having an occasional problem with a "sputtering" engine on my 2002 Ram 1500 (5.9 liter).

Here's the scenario: ......The motor starts & idles just fine, and also accelerates from an initial dead stop just fine. A frequent problem then occurs when I let off the gas in order coast through a yield or come to a stop. When I gently accelerate after just letting off the gas, it tends to sputter & hesitate, but then runs great at full power after I get above 25mph or so. This problem only occurs at slower speeds. If I pull the truck over while it is still sputtering, then turn off the engine & re-start it, the engine runs fine again. I am not getting any "Check Engine Light" or error codes (DTC's) activated.

Here's what I've tried so far: ......Installed new plugs & wires, cleaned cap & rotor, removed & thoroughly cleaned the entire Throttle Body, installed new Idle Air Control Valve (IAC) & Throttle Position TP Sensor (TPS), verified proper vacuum w/ no leaks detected, verified no leak in the plenum, the PCV is good, & Oxy Sensors were just replaced. I have connected a fuel pressure gauge, and the pressure remains steady at 49psi (with NO noticeable fluctuation). I've disconnected the battery (& drained all residual power) several times in order to reset the PCM.

I was wondering if this is due to a glitch in the Powertrain Control Module (PCM), and if I need to get the computer re-programmed in order to resolve the problem. "AutomotiveComputerExchange.com" can provide a fresh re-programmed PCM for around $280, but I was wondering if this is a necessary step to take.

Any advice-help would be appreciated. Thanks!

(2002 Dodge Ram 1500 ST Sport Quad-Cab 4x4, 5.9 liter, automatic, 79000 miles)

 

Try this link, it involves rerouting the spark plug wires. Read the entire TSB and make sure you click on the V8 picture to get the info for your motor.

http://dodgeram.info/tsb/1998/18-48-98.htm

 

Thanks for your reply. The spark plug wires have been verified, and were all routed to allow for complete individual isolation, so the source of the problem must be something else. Thanks anyway!

 

Man you have checked everything, I wonder if there is a way to run a check on the PCM to see if that is the problem. I would probably research that before dropping the 280. Good luck

 

post this question in the 2nd gen forum. you will get more replies. losts of 5.9 guys over there.

 

The problem you describe is exactly what my '02 5.9 is doing. Did you ever figure out what the problem was ?

I've had mine into the dealer and they haven't been able to diagnose. They thought it might be a check valve in the fuel tank allowing fuel to drain back into the tank and not having enough when needed until it purges the air out. Does that sound plausible?

Any help would be appreciated.
Thanks,
Effer

 

have you looked down the throttle body for oil, for a plenum leak ?

also 5.9 are know for clogging cats if the plenum is bad

 

Haven't checked for Plenum problems but will. If it were that wouldn't the problem be more constant instead of random ?

 

I have the same problem with mine 02. Have to replace the catalyctic converter. Like "lastrights" said.

 

I have same problem. Did replacing the cat work?