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-   -   1996 Dodge Dakota. Engine stutters (http://www.videokarma.org/showthread.php?t=266396)

MRX37 02-23-2016 12:30 PM

1996 Dodge Dakota. Engine stutters
 
Hey guys. Awhile back you might remember I posted about my 92 Dakota. Well long story short it had too many problems, including the frame rotting out of it...

So not wanting all the work and all those good parts I spent money on just going to waste, I decided to look for another Dakota from the same generation, and by sheer luck I scored a 96 Dakota for only $750

The frame is solid, the trans shifts right, it has more get up and go then my 92, it's in better condition overall.

Same specs as my 92:
3.9 V6
Automatic
4x4
Extended cab

But this is why it was $750 and why the guy was so eager to get rid of it:
https://youtu.be/jrjr5K0hyhg

Now you might notice a few issues in the video. The tachometer isn't working (My 92 did this occasionally after I pulled the dash to fix the hot/cold slider switch). Also, the shifter needle says it's in Second, but Second is actually Drive. Drive is neutral, Neutral is reverse... basically the shifter is off by one place. Linkage issue?

But right now the engine stuttering is the biggest headache. This also occasionally happened on my 92, but this truck has it much worse. It drives pretty normally when the engine is cold, but after it warms up the stuttering sets in.

Idles smoothly. After getting up to speed, the stuttering will pretty much stop. It's accelerating up to speed that's the problem.

Not sure where to start looking. The ECM has a re-manufacture date of 2013 so I doubt that's the issue. My thought is it's something in the wiring and might also explain the non functioning tachometer.

Second thought is cap and rotor, but I changed that on my 92 and it didn't fix the issue.

Now looking under the hood I can see that somebody's had a crack at the wiring before: (Links for big images)
http://i.imgur.com/X3P7ula.jpg
http://i.imgur.com/YYgLlYa.jpg
http://i.imgur.com/zQ6N3F7.jpg
http://i.imgur.com/kE2j1ll.jpg
http://i.imgur.com/3B15A5G.jpg

So it's like where do I start...

Oh I did see something possibly related on another forum, something about a #115 splice According to a poster on that board:
Quote:

Splice #115 is something the factory did. It's 3 wires spliced to one larger wire. Re & red w/ white stripe are the colors I think. I't down in the wiring harness under the PDC. About 6-0 inches down from the PDC. You'd have to peel the wire loom and tape back
If I knew what the PDC was and where it is I'd look there.

Should also mention that this being a 96, it has ODB II, meaning my ODB scanner works on it. However it shows no trouble codes.

Olorin67 02-23-2016 02:57 PM

could be lots of things, how do the plugs and wires look? plugged fuel filter or fuel pressure issue?. look in the exhaust pipe- any black soot? then its running rich.

Olorin67 02-23-2016 02:58 PM

since there are no trouble codes, look at the non electronics stuff first, like vacuum leaks.

MRX37 02-23-2016 03:09 PM

Okay exhaust pipe there's a little gray/black soot but I don't think running rich is the issue. Spark plugs I haven't checked yet, but, and I forgot to mention, the mileage is high, but both the engine and trans have been overhauled recently, so I doubt it's the plugs, but I plan to check later on.

Also, like I said I had this issue on my 92, and on it I did plugs, cap and rotor, fuel pump and filter... never solved the issue. Basically I am positive it's an issue with the wiring, or a sensor.

Should also mention I have receipts for the repairs done, that's how I know about them. Also I have another question:

I want to swap over the dash from my 92 as it's in better shape then the one on this 96. However the dash has the VIN plate riveted on it. If I swap dashes the VIN changes and that may cause issues. So should I leave the original dash in place or can I do something to swap VIN plates?

Olorin67 02-23-2016 05:39 PM

there might be electronic/wiring changes between 92 and 96.. you'd be surprised how much they change stuff from year to year. Better check out the swap before you get into deep with it.

Eric H 02-23-2016 06:16 PM

Sounds like an ignition miss to me, possibly wires.

MRX37 02-23-2016 06:17 PM

I'm going to leave in the original dash for now. Later down the road I might have a shop do a proper swap.

So the engine stuttering. I want to rule out electrical issues first before tackling more obvious causes. I'm very sure it's an electrical gremlin, but if it's not I'll be happy to be wrong.

So on the electrical side of things, where do I start?

Quote:

Originally Posted by Eric H (Post 3157020)
Sounds like an ignition miss to me, possibly wires.

Spark plug wires? i'll start checking those tomorrow.

Username1 02-23-2016 06:27 PM

I would not replace the dash also because of differences in years & wiring.

In one of the pictures you posted it looked like there are wire crimp type
repairs on wires down the passengers side near the engine, I would replace
those with soldered wire covered with shrink tubing and coat the ends after,
with silicone. They looked like they ran from the top of the engine, down
the side near the belts, they were lone and not in a "harness" seems like
someone went playing in there....

When the engine warms up the mixture leans out, and harder to ignite, so
look at spark plugs, wires, coil, onto other things not spark related, check
throttle position sensor, O2 sensor, and fuel pressure regulator. I seem to remember
a post about alignment of the Throttle sensor as being critical on these engines.

I have a '88 with strange engine stumbling, it has spit injection, I think '96 has port
injection right ? - 6 individual injectors...? I have 2 mounted above the throttle
plates on what looks like a carb. base. On a number of Dodge forums this
problem is well covered, and for the most part unsolved. I read once that resetting
the computer fixes it for some, and for me, resetting it gives me a few months of
better running, so I just do that....

I had a bad O2 sensor, it is a 4 wire type, the thing smoked and MPG was around 12,
I put on a honda 4 wire I had here, and it went the other way, 26MPG and odd idling
problems, bucking, stalling..... Unplug the computer for a few seconds and it gets
better for a while.... I also replaced the computer, no fix....

You should also look at the EGR since it only comes on after warm up and at certain
speeds.....

From your short video it looks like it's missing once in a while, that's either too lean,
or a spark problem. Possible timing issue too, so check the distributor,
I read something about that on these vehicles too......

Another person said that if the computer is not setting codes you have to look
at other things that the computer does not look at. Like the ones I listed here.

Also when mine had a bad O2 sensor, the computer identified it as bad,
and I tested it with my volt meter, and it seemed to be working well within
limits, and it was not until I replaced it that I fixed it, So while it may have
read within specs when I tested it, at some time while running the computer
didn't like what it was doing. Moral, Well, you may have a problem with a
part that the computer may not be identifying as bad yet....

I have also seen spliced and taped wires in one part of my wire harness,
the splice is 2 wires tied to a larger wire like your quote, the wires are
soldered, and taped inside what looks like factory cloth tape, so I didn't
touch it, I think you should do the same........


Good luck, keep us posted !

I like your new toy ! Looks cool !

.

MRX37 02-23-2016 07:04 PM

Thank you Username1. I should have posted a longer video. Might do that tomorrow.

It does this while the engine is cold, but does it more and with more consistency after it has warmed up.

Username1 02-23-2016 07:24 PM

You might also want to check and see if the engine rpm thingie gets it's sensor
readings from the same sensor the computer uses...? I would think not since
it's not setting codes..... A very good first investment is to get the original
factor service book off ebay, they are 400 times better than Chiltons and all
the other crappy ones for sale at auto parts stores...... You also get nice
flowcharts of parts to check and how to check them in the factory book...
And the are pretty good about covering things well.....

MRX37 02-24-2016 11:17 AM

All right I just got back from a longer test, which was also a good opportunity to test the 4WD, and the truck passed with flying colors.

Apart from stalling when I backed out of the driveway, it behaved just fine today. Here's the video. That should explain things better:

https://youtu.be/v7cZiP2S0qQ

So, this can rule some things out, right? What can this rule out?

Olorin67 02-24-2016 11:31 AM

if it does it more when cold check the temperature sensors, those can give bad readings, but still not trigger a failure code. had a bad sensor on my old 1990 Mazda once, that took a couple of years to track down.. it would start losing power, but only on the rare occasions when you got the car good and warm. like pulling a trailer on a hot day. The shop could never duplicate the issue, and always claimed the part they replaced would solve the issue, a month latter it would happen again...

MRX37 02-24-2016 06:02 PM

I think it's not temperature related, or temperature plays a secondary factor. I wonder now if it's humidity related.

Today was cold, wet and just nasty, and the truck did fine. yesterday it was cold, but it was also dry.

I'll test it again tomorrow. We'll see what tomorrow brings.

Kamakiri 02-24-2016 06:59 PM

Grab a spray bottle full of water and start misting around the plug wires and cap. If it's that, the engine will stumble worse. Then, grab a can of carb cleaner and spray around the intake, TBI, and vacuum hoses. If it's a vacuum leak, you'll hear a change in the way the motor runs.

MRX37 02-24-2016 07:26 PM

Hold on isn't carb cleaner flammable? I feel kind of uneasy about spraying that while the engine's running, and which intake? the air intake? Like where the air filter is? TBI... Throttle Body Injector?


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