Hello all this is my first post on this forum. Active member of other car forums, but looking for help on the Ram now.

What I got: 2001 Ram 1500 with 360 motor

Problem: Start and runs great. Only under load in around the 2000 RPM range (give or take) at highway speeds. Going up settle hills or into wind, the Truck will backfire and pop going up the hill. Also just recently my buddy noticed that the Vent air would stop coming out right at the same time, every time I would find the truck backfiring. No major noticeable loss of power elsewhere in operation, and I can Shut down OD going up the hill and it will jump RPM and seem to push threw to top of hill like its running fine again. (Vent comes back too)

Also on possibly related note. I had a month or so before all this started an Engine error code that popped up indicating an O2 sensor problem. It cleared and has never come back. (can't remember the exact code sorry) Backfire issue did not occur for a long while after that code came and went.

My own deductions/ tests: First I was thinking CAT, before I noticed the air Vent thing too. Did a back pressure check on the CAT at the muffler shop. Running wide nice and clear. No issues what so ever.
Now I'm thinking I have a vacuum issue, that is if it can cause this kind of symptoms.

My question/s: Can this be a vacuum leak? If so whats best way to hunt that down... First visual checks haven't shown anything obvious. Could this be an 02 sensor? Any other ideas?
Would love to hear from someone that had the same symptoms. And thanks ahead of time.

Will gladly post the resolving answer to this forum once problem solved.

 

I think it's a vacuum leak. I guess the most common spots are at the cruise servo by the battery and somewhere on the vacuum lines underneath for the 4WD. Mine was in a metal line underneath.

 

my vacume leak was on the firewall left side. rubber was rotten, replaced was fine.

 

Well truck just threw two new codes at me tonight.


P1596 Speed Control Switch Always High Speed control switch input above maximum acceptable
voltage.

This one seems unrelated to at least this exact issue.. but the big one is:



P0442 (M) Evap Leak Monitor Medium Leak
Detected
A small leak has been detected in the evaporative
system.


ophidia
You mention the 4x4 system. That reminds me presently has an actuator motor on the front axle that is "supposed" to be bad according to my local crystler dealer. It may be that is getting a worse leak in it.

Can I just plug the two lines at the motor to take the motor out of the equation. Or is there some kind of flow that has to exist?

Still looking over those lines....

I'm thinking my Backfire issue may be because my 4x4 is out....... odd combination of failures. :P

Still looking for suggestions, and will be touching back.

Question:
Any pointers on ways to find vacuum leaks besides visual?

 

Looked up 442. See that is a problem in the Gas cap or evamp area. Not vacuum leak.... back to drawing board.

 

You could try capping those 2 hoses, and see if it helps. Also , the hoses that are under the battery tray for cruise control are not visible without removing the tray itself,IIRC.

 

Problem solved: Turns out to be a faulty plug wire at the Cap.... Nothing more nothing less...

Had I only know the last shop only 6 months ago did not replaced plugs and wires like they were asked too, I would have found it more necessary to check the plugs and wires out deeper. Oh well.. trust no one

 

Thanks for letting us know what the prob was, amazing that had anything to do with the code you were getting.

 

Im having the same "popping" issue under load at low rpms and and awful "miss shake" at cruising speed as well. I have replace my plugs and wires, but the issue still persists. I have not, however, changed out my cap and rotor......could this combo be the culprit?
I have no DTCs......I DID notice the other day that the passenger side exhaust flange at the manifold was leaking,,,,,hoping that was my problem, I tightened it , but still this DAMN POPPING!!!

 

New member, 2002 dakota sport 3.9 liter engine 129000 km, 3 days ago engine start to rattle and backfire check for code got P0152, need help.