My Inlaws have a 96 van. they recently tried to get it smogged and it failed due to CEL on. the codes it came out with were p0300 multipe random misfire, p0301 misfire on cyl 1, p0303 misfire on cyl 3, p0305 misfire on cyl 5. van has a 3.9l v6 engine. it DID pass the actual enissions output portion of the test

looks like the whole driver's side is misfiring.

plugs and wires appear to be newer.

in my searches through threads here, it looks like there might be an issue with spark signals jumping wires. i am not sure if this is the case yet though

i have already checked and confirmed firing order and cylinder location per diagrams i found here on the forum.

1-6-5-4-3-2

6 5
4 3
2 1
Front


what can i do? what is my next course of action?

 

I have been wrestling with this exact same problem for 2 years now. My code reader views live information which allows me to see that #3 is the worst, followed by #5, then #1. It's not the computer, crank or cam sensors. Nor is it a vacuum leak, the plugs, wires, cap, or rotor. I have gone as far as pulling the intake and cleaning it and reinstalling it with new gaskets. Nothing has worked to change the problem in any way. At this point I believe it's a mechanical issue, possibly along the lines of a crack, or cracks in the head on that side. Another possibility is weak valve springs on that head.

Compression is good on all cylinders, so bad rings or burnt valves are ruled out. I thought maybe a worn/stretched timing chain, a worn distributor, or a warped flywheel, but those would effect cylinders 2, 4, 6 as well and those are fine.

If you do find a solution i would sure be interested in hearing it.

 

should i look into seperating the plug wires more from each other?

i have not yet checked the cylinders to make sure all the plugs are tight, my FIL replaced them... it's something i at least want to check out

 

Here is the TSB for routing the plug wires.
http://dodgeram.info/tsb/1998/18-48-98.htm

 

i will work on that this weekend, they have not had the light come back on, but if i can do a simple repair to possibly help out the situation, why not right?

 

bringing this thread back from the dead!

this van is now my daily driver

has recently had a 300, 301, and 302 present....... and i had soem severe running issues.... like it was fine, then wouldn't go above 30 mph, then nothing over a crawl.... would die sometimes, and run rough..... it did seem low on gas, htough, not low, but not full..... felt like it was starving for fuel...... was at 1/4 - 1/3 tank...... i cleared out those codes, and have refilled the tank to full, and it is at half now with no issues, but.... my father in law said dont drive over 55 mph because it is old and has problems.... it does have 186k on the chassis, and he said there is a rebuilt engine... but i dont think that has anything to do with my fuel problem?

 

so i got below half a tank yesterday, and although things werent as bad, i did get some sputtering on the freeway.... got a 300, 301, 305, 306 ---- so most cylinders were misfiring...... limped it to work, and then reset the codes, and put $40 in gas into it... no problems o nthe way home.....

 

Time for a new fuel pump.

 

... and the fuel pump is in the tank.

Has the cap-n-rotor been changed? If so, make sure it has copper/brass contacts. The aluminum type is junk.

Did you do the ignition re-routing in the TSB Alloro posted? Even the wire looms help prevent the misfire problems too. These are cheap at the auto stores.

Jegs, Summit and Rockauto all have the fuel injects for our engines. Just price and shop around.

 

i actually did the rerouting of the wires back when i originally posted this thread..... i htink it helped, but who knows.....

so yesterday, was on my way to work again, when i got the needle just to the top of the halfway tickmark...... sputtering and misfiring/dieing again...... limped off the freeway, put $35 in gas, and was good to get to work and home.......


so before i actually drop the tank and replace this thing, do the people here @ the forum think this is my problem?

i did see another thread someone else started about the exact problem and it being a fuel pump/filter/sending unit piece


what all do i need to replace it? i don't have spare time to have it down, so i will need to get everything beforehand

also, what brand of pump? i have seen several brands and several different looking designs.....