Hello all, and thank you in advance.

I am a former Volvo mechanic. I just bought a 1996 Dodge Ram Van B2500 with a 3.9L magnum? V6. Has 119,xxx miles. Pretty good little van, it's basically a small conversion van. Paint is immaculate, even with the running boards and fender flares gone. Inside is a 9.

Anyway, it had a miss under load condition that happened occasionally, and a rough idle, no big deal. The CEL was burned out so I scanned it, came up with nothing unexpected: General miss, miss 3, miss 1, miss 5.

Erased codes, reduplicated condition, pulled codes again. Found general miss and miss 1. Checked cyl 1, found hole in plug wire and weak spark. Changed cap, rotor, plugs, wires. BW on the cap, rotor, wires, Champion on the plugs.

Erased codes again, drove van. Much stronger accel, nice smooth idle. No codes, no repeat condition. Ran this way for maybe 3 days.

Then, 2 days ago, same miss condition, repeated itself yesterday AM for the wife, not me. Pulled the DH again, hooked up to the rail with a gauge, drove the van a billion miles in ALL conditions, 50 psi all day long.

Now I have the gauge hooked up with the DH off and the wife is complaining about the engine being "too close" to her, I need ideas. I suspect the pump because the former owner said "I replaced the FP" which makes me think they didn't or that they used an Airtex. Gonna yank the tank hopefully today, in the meantime, any ideas?

 

Jeez....tough crowd....(chirpchirp)

 

.....

 

Not sure about cracked head or plenum gasket as it ran great for 3 days after your work. Personally, have lost love for Champion. They just seem to run too cold for me. I have also seen bad factory plugs. You didn't say if this second time around you found any codes, or I missed it somewhere. Old school would be, pull plug wires one at a time while running and see if one cylinder fails to drop out. What color were the old plugs? Did cyl #1 have a black plug when you changed it, and the others were better colored, as in maybe bad valve guides, ring etc?

Another possibility, don't let wife drive it.

 

Replace the crank sensor.

 

I had the same exact symptoms that you had..misfire one day, no misfire the next...misfire the day after that etc....did all the standard stuff, CPS, wires, coil etc etc - I kept on getting misfire codes...

It did end up being a cracked head. There are totally updated heads for the 3.9. Clearwater Cylinder Head has them. I recommend them highly -great service and parts..

http://cylinder-heads.com/details.cfm?itemid=1827

Im not saying go run out and buy these, but after you go through everything...this is probably what you are going to have to do...

 

UPDATE:

Had the wife drive around with FG hooked to rail and DH off, as I drove the **** out of it and was never able to duplicate the condition with the gauge attached. She duplicated it and reported no change in fuel pressure- 50psi all day, spec is 49.2+-5psi.

Pissed off when she picked me up. We turned on to the main drag in the van, FG still attached, DH still off. I poked the crank sensor with my finger and the van died. Cranked it back with a wire wiggle and went to the parts house. Problem solved.

Thanks for all the help.

 

Seems there are several causes and so several fixes for this problem. I had similar symptoms, stalling, no warning, no code except IAC, which I swapped and found no improvement. Put in a new coil when the truck died and left me stranded on a very busy highway. Had to walk a couple of miles to get it, and then back, and install in the traffic and heat. But as soon as I turned the key it fired right up and hasn't had a stalling problem since. Problem solved.

 

I have no use for Champion plugs in Mopars due to past experience back in the 70's and 80's. Every time I used them I had problems within days,I'd replace them with Autolite or Motorcraft plugs and no more problems.
BTW,how many of you old timers remember KLG,Lodge and Prestolite plugs?

 

I wouldn't put autolite in my lawnmower.

Van acted up again, pulled tank down, found POS airtex pump. Ordering delphi pump from rockauto. Eff airtex- nothing but trouble out of this garbage company. They should be sued.