Stalling at red light
 

I have the 01 Ram ven w the 318. The customer had let it sit up for 6 months. So now it runs fine on the highway. But at city driving at a red light it stalls out. Also i can hear a major vacuum leak when it does this. I traced the vacuum noise to the back of the air horn. Not being a dodge man i can only say there is some kind of solenoid there that apparently is opening up and causing loud vacuum and shutting the engine down. Get trouble code p0441. Pointers?

p0441 is incorrect purge flow, so, likely a vacuum leak somewhere.

Need to pull the throttle body, and clean it out really well. The 'solenoid' on the back is the idle air control motor, and it is essentially a controlled vacuum leak to maintain engine idle speed. The well it's in tends to get crudded up pretty bad, and then you have idle issues.

Thanks for the quick reply. Actually i was told an incorrect code. The correct code is p0411 according to the owner. I also pulled the idle speed control motor and polished the plunger and the seat as well. Cannot locate ant further vacuum leaks.

Does you Van even HAVE an AIR pump?????? I don't recall seeing those on the Magnum engines.....

Need to clean out the well from both directions. (above, and via the hole the IAC goes into.) Once done, you need to reset the PCM as well, and let it re-learn the 'zero' values for IAC. Basically, disconnect the battery, turn the ignition on, (or headlights, doesn't really matter) turn whatever back off, hook the battery up, turn the ignition to "On", (not start), count to ten, and THEN start the motor. Don't touch anything else. The PCM should figure things out fairly quickly.

Thanks
 

Yes. I did all the things you suggested in your response. Unfortunately, the problem persists. In stop and go traffic at operating temp the IAC will pop too far open and create such a vacuum leak the engine stalls. Replaced the IAC and made sure the well and seat were polished clean. No other vacuum leaks are found anywhere on the vehicle. Also if the IAC seals back up i then get a surge at 10 or 20 mph (slight throttle). And the p0411 code continues as well. I am stumped. Could the ECM be suspect? BTW no AIR pump.

That's the IAC's job. It's a computer controlled 'vacuum leak', as when your foot isn't on the gas, the throttle plates fully close up the bores.... so, the engine needs air from somewhere. It's likely the problem is the PCM is CLOSING it too far/too fast, and the engine stalls.

What brand IAC did you install? The aftermarket fellers don't always play nice. In fact, more often than not, they make the problem WORSE, not better.......

Thanks again
 

The IAC i installed came off a knowingly running engine that is in a van that just got smacked and is in the u pull it yard. What seems to be happening is the IAC is opening up Too far after a few seconds at a red light and then i get a stall. Also the customer just informed me that the ECM is a replacement computer that was put on last year and the check light never went off. Plus the van has sat up some months with less than 50 miles put on it. Could the ECM be sending the wrong voltage to the IAC causing it to open too far?

Reset the PCM. Disconnect the battery, turn on the headlights for a few seconds, turn off headlights, reconnect battery. Turn the ignition on, (not start) do not touch anything else, count to ten, start the motor. Let the PCM relearn idle. See if that helps.

Reset PCM
 

Yes. I have reset the PCM exactly the way you described. No luck. The problem continues. This thing has got me licked right now. Any other ideas?

Just a shot in the dark.... Have you tried disconnecting the front O2 sensor, and driving it that way? Does it still stall?

What's the fuel pump pressure?
Was it really only 6-months it sat or could it have been longer, making the gas closer to a year old?

Gas age
 

Gas could be a year old. But customer treated the fuel woth Sta-bil fuel stabilizer. Not sure if that makes a difference.

Fuel pump pressure
 

Fuel pump was replaced 1 year ago when he was having related issues by another mechanic. OEM parts were used-not aftermarket.

Fuel stabilizer doesn't always work.... Year old gas is going to be nasty, regardless of what he put in it..... How much gas does it have? Have you added any more? Burned thru much?

Gas age
 

Put in 10 gallons yesterday. It had a quarter tank before that. I had suspected bad gas yesterday and put the 10 gallons in after resetting the PCM and test driving it. Am getting ready to test drive it again right now after unplugging the front O2 sensor.

O2 sensor disconnect
 

Disconnected the front O2 sensor as you suggested. Drove van for 1 hour in stop and go. Stalling has stopped
Should i replace the sensor or does this indicate another problem.
Thanks very much.

Replace the sensor. NTK, or Denso sensors ONLY please. Skip Bosch, these engines don't like 'em. :D

how would the o2 sensor make the van stall,does it make the van run too rich,and then just shut off, Ive not heard of this before,,,,

O2 sensor measures oxygen in the exhaust stream. If it becomes inaccurate, the PCM starts basing injector pulse on bad information, and you get odd problems. Removing the O2 sensor from the equation, and the stalling stops, indicates that the O2 sensor has indeed failed, the PCM just can't figure that out. O2's have MANY failure modes that WON'T set a code. Without it, the PCM tends to run the engine a bit on the rich side, so, you get rough idle as well. There may also be other issues contributing to the problem..... When's the last time the engine had a tune up? How are the cap and rotor? Plug wires? Are they routed per the TSB?? (a good set of plug wires will alleviate some of the issues the TSB addresses, it was all about cross-talk on the wires, and firing the wrong cylinder at the wrong time.....)

Replace the sensor, reset the PCM so it forgets everything it learned with the bad O2 sensor, and let it relearn. If everything else is up to snuff, it *should* take care of the problem.

I never knew that , thank you very much for that reply, I’m always learning something new here,,,,thanks,,,

Thanks again
 

Being a newbie on this forum i must say this is a treasure trove of good info and good folks eager to assist.