I have a 2000 dodge ram 1500 3.9l. This is what I have replaced so far ignition coil, dist. cap and rotor, spark plugs.The problem i am having is it will back fire, misfire, and stall. If I was to put my hand at the exhaust I can feel like a pulse of air not a normal flow. The problem is not all the time, it seems to have a mind of it's own. There is no check engine light or any codes. I am at my wits end on this. When I replaced the dist cap and rotor it ran fine for 2 days, today it started back up again with the back firing and misfire. The other day when I was replacing the dist., I notice the throttle body was dirty. I cleaned the best i could. Can any one give me any ideas and what to try next.

Thank you
Wallis

 

Does it do it all the time? Or just when you step on the gas? Does it have a stable idle? Is it firing on all cylinders? How many miles on the truck? Have you rechecked that everything is tight, and in the right place still?

 

It does it when I step on the gas, It idles fine. It also does it when Im driving down the highway .The miles on the truck is 100750. everything is tight and all the plug wires are routed as they was.

 

I'd have the catalytic converter checked.

When was the last time the wires were replaced?

 

if you reset the pcm, does it run any better for a couple of days ?
oftentimes, backfiring is related to firing out of time problems, which can be caused by cam position sensor in distributor, or crank position sensor.

it could also be a vacuum leak, or flooding, or starving for gas (weak fuel pump), or maybe clogged up cat.

see about checking fuel pressure at the rail with a testing gauge. should be 49psi on v8, not sure about v6.

edit- +1 on wires. i had a honda that was skipping under load. one of the plug wires was burnt and shorting down in the head tube.

 

I haven't replaced the wires yet, I was heading that way next.

 

Some more info.

I have not got my wires yet will Saturday. I was reading in the service manual and it said to remove one spark plug wire at a time, the only one I could not get to was the number 5 plug wire. Anyway I went around removing and putting wires back on still no change in the running of the motor it still cuts out. I did the test with the transmission in neutral, not in park. The manual states if there a change in the running of the motor replace that wire, but I did not get any change. Any other ideas, am I going in the right direction about chaning out the plug wires, or should I be looking else where.

One other thing, I got my code reader back from a friend, no codes are showing up

 

I would definitely change the wires next, its a relatively cheap solution, and you should have new ones anyway if you replaced cap, rotor, and plugs...

check out this for proper plug wire routing https://dodgeforum.com/forum/2nd-gen...lug-wires.html

 

Well I replaced my wires today, I also reset the PCM. I also noticed some corrosion (sp) on the battery positive terminal so I cleaned it while I was there. She started up idled fine, drove it up and down the road for a bit until, my engine temps was normal. Got hard on the gas, no backfires, stalling or any other problems. She a little low on power but what you expect from a 10 year old truck. I will run her around for a couple of days to see if there any problems or what not.

I wanted to thank you all for the help. If I need anymore help I will come here first.

Thanks again
Wallis

 

Thanks for posting the end result, we appreciate that.

Stick around. Lots of knowledge here.