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:
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.

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.

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

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?

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.

Sounds like an ignition miss to me, possibly wires.

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?

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

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 !

.

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.

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.....

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?

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...

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.

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.

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?

carb cleaner is nasty stuff it will quickly destroy any plastic or rubber components, Ive taken apart many carburetors that were ruined by it. it should only be used to remove gummy deposits from metal parts, and even then, i would only use it after milder solvents had failed.

any petroleum product is bad for rubber parts.

Yeah I don't think I'll be doing that.

What I might do tomorrow, weather permitting, is inspect all 6 plug wires one at a time, look for cracks or anything questionable.

I've heard an unlit propane plumbing soldering torch will do the same thing with the added benefit of being easy on plastic and not leaving any flamable liquid on hot surfaces. If by some fluke the engine somehow lights your torch you have a small controlled flame rather than an engine soaked in a lit lake of flammable liquid.

I've yet to try it, but I plan to use that method to leak test the vacuum system on my Lincoln Mark V...First I'll let the air intake suck some of that propane in to confirm it changes the idle noticeably, then start looking for vac leaks....Once it gets warm.

back in the early 80s,we used propane to adjust carburetors on ford products.i use brake cleaner to test for vacuum leaks.my friend has a 3.9 dodge 1500.it stumbled and idled rough.bad egr valve.stumbling could be anything.wires are a good start.keep us informed

The only thing worth trying is the water bottle to check for ignition problems....
However, once you know you have a reliable - working ignition system, you still
have a Dodge Dakota, and there is a known odd engine behavior that involves
stalling, stumbling, hesitation, etc. And there are several forums where people
have been battling these engine problems for a long time. Your best bet is to
use this vehicle over a number of months, note when some of the problems seem
to be better, or worse, and use this observation to search the forums, and google,
to see if you can move forward to a reasonable solution.

Since you just got this truck, and have had a few good days, and a few bad ones, it
will take a while to get to learn patterns.....

You might want to do some simple things, Get a voltage monitor, (analog with a needle)
And tap into the power line to the computer and be sure there is not an intermittent
connection related to bumps, stuff like that. Check to see if your car has a ground strap
from the engine to the chassis, replace it, add one, be sure it's working, because the
engine shakes all the time it's running, and if the ground is bad, all sensors may
be good, but poorly grounded to the computer..... Will it set a code for that ?????

Do a voltage monitoring to the fuel pump, ignition coil.... put it in the cab and watch it
when you drive, especially on trouble days.... Voltage check the ignition system,
you could have ignition switch with changing resistance when on.....

You might also want to get a fuel pressure gauge too, one for the cab..... Does not have
to be perminant.... Watch it for a good while, watch it closer on trouble days.....

You should do a reset of the computer now and then to see if it changes behavior....

There should be a few noise suppression caps around under the hood, you might want
to get new ones, be sure they are grounded......

Put on a vacuum gauge and put it in the cab, watch it on good and bad days..... Don't
forget it will read less on days the engine is not running well.....

Spraying carb cleaner at the engine or hoses is not going to help, you don't have a
constant leak, and it's not going to be big enough to make the engine run differently
if you spray anything at a leaky hose.... You can just physically check the hoses, and
connection points.... If anything you may have a leaky motor, or vacuum selector
for the heater controls.....

But then again, this car has been in the wild for 30 years, and several forums with
hundreds of postings and the problem still persists unsolved.... Be very very patient !

.

Interesting. Could you elaborate on that?

I'm not saying shoot it all over the engine willy nilly, I'm saying give a couple shots near the base of the intake and at the throttle body base. You can use a light fog of it on vacuum hoses as well. I use carb clean to clean greasy deposits on just about anything under the hood. I've been working on cars for almost 30 years and never melted anything doing so.

I would replace the wires trust me just for the piece of mind. They might look fine with no cracks but still be worn out. my 94 Saturn developed a dead cylinder after the catalectic converter stopped up even the wires were not that old I chased a dead no 1 and it would not miss all the time, so I replace the wires and solved the dead miss.

I've been thinking about this, and I think before I go shotgunning parts I need more data... meaning I need to narrow down when it does this and when it doesn't.

Today it's colder and drier, and I need to run an errand. Taking the camera with me. It will record the full drive. We'll see how it acts.

Truck went crazy today, then died!
 

Okay... Okay I made it home, barely. The truck started out right as rain, but on the way back home it started going nuts and it got worse and worse until it flat out stalled. Then I managed to limp it to my home street where it completely died half a block from home, I mean the ignition switch wouldn't do anything.

Fortunately I got it all on video!
https://youtu.be/9yij-eTxcvk

I drove for about 25-30 minutes total. I edited out most of the drive to the place I was going as the truck behaved fine. However I left the trip home mostly unedited. Around 4:40 in the video is when things get interesting.

So the video is a bit long but I think it can explain what this truck is doing far better then I can. I lucked out in that it died half a block from home.

Well, the video would have been more useful if you pointed it at the speedometer and
gas pedal at the same time so we could tell speed and gas pedal position.

But with the sound and description via audio, I would now take my chips and put 70%
of-em on a bad distributor, or something like bad intermitant spark, coil.....? and 20%
of my chips on fuel delivery, 10% TPS, MAP, Discounting the last 10% because no
codes are set.....

I don't think this is the standard Dakota engine problems on all the forums..... Spitting
through the carb is classic ignition problems.....

I had a wire go bad in our Prelude, I think it was 2 wires, A few years ago.
It would start, warm up & idle fine. Put it in gear - step on gas and it would
spit through the carb body, buck, all the stuff your tape sounded like.....

And it didn't do it all the time.... The carbon wire stuff got hot discolored
cracked at the very end near the spark plugs...... You could see it once you
pulled the boot off..... Cut it back, reattached it and they are still on the
car running today.....

You might have a distributor problem, pickup, or some other thingie in there....

.

Yeah I didn't want to hold the camera for that long of a drive, so that was the best I could do.

Showed this video to a couple other people, one whose been a mechanic for 40+ years. he says check the ground wire for the fuse box, and the ignition coil. also could be the crank sensor. So weather permitting I'm going to dig into the wiring tomorrow and swap some parts from my '92.

As you can see at the end of the video, the ignition switch just up and quit starting. Would like to sort that out first as right now it's not parked in the best of places.

Yah, I forgot to say also, my neutral safety switch does not let me start it up
on 1 out of 8 occasions too..... Could be N or P I will have to go up and down
the gears and back to P or N and try again.....

Yah, could be a ground or some wire around the fuse box, don't forget Dodge
has this giant plug that goes through the fire wall.... Last resort on that....

.

Oh yeah the neutral safety switch... I doubt it but that's not hard to swap.

But it looks like we're getting MORE SNOW so this will have to wait...

All these problems appear to be the fault of a vehicle that was stored, undriven.
A friend bought a Chevy Lumina minivan, that exhibits much of the same problems. Stumbling, poor idle, too fast or too slow, misfire etc.
He wanted a car that didn't have to be emission tested and nice shape for it's age.
It turned out to be, the car was traded by a lady who got the car from her late father. It wasn't driven for like, three years. Newer vehicles, just don't age very well. :sigh:

..... well I tried to swap neutral safety switches only to take the one off of my '92 and have it piss trans fluid. I dont remember my '93 doing that when I swapped switches but needless to say I'm not taking off the switch on my '96. I can try cleaning the connector though...

And far as I know Dieseljeep this vehicle wasn't stored for very long. The previous owner drove it up until it started acting too crazy for him to rely on.

I may just take it to a mechanic. I have some money now and I am sick of working on vehicles in Winter time.

Find a mechanic, that's just a little sharper on Mopars. Taking it to the dealership probably wouldn't work, as most dealers don't take 20 YO vehicles seriously and personel, familiar with a truck that old are retired by now. :sigh:

I wouldn't set foot in a dealership to save my life.

I showed the video to a mechanic, their diagnosis: water in the gas line...

...could it be that simple?

I'm going to get some help pushing it up to level ground where I can jack it up and have a look at that starter. With any luck that's the reason it won't crank anymore. I did start it more then a few times trying to get it home...

I'd check the solenoid (if it ain't hard to get at) before pushing it. If the solenoid is bad you may be able to start it by keying it to run and cranking it by manually bypassing the solenoid with a jumper cable or a wrench across the contact terminals.

Having worked at car dealerships since 1989, sometimes it's worth not having to deal with the aggravation.

My $400 1996 Grand Caravan is going right to the Dodge dealership come spring to fix a blend door issue for the passenger's side that wasn't cured with a blend door motor nor is anything sticking....the blend door motor is getting a stuttering voltage and not changing the heating position.

Screw it, I'll end up paying $300 or more to get it fixed, but I'll drink their coffee and have a pastry while they plug their machine in and take 20 minutes to diagnose something that I spent days working on.

Got an update for you guys. Took it to a mechanic a few days ago and they found the problem apparently. Wire with a damaged casing behind the alternator. So I've been driving it the past 2 days and it's been behaving itself.

Now I'm tackling the interior, swapped tachometers and now I have a working tach. Went to swap the stereo and... oh Jesus Lord help me...
http://s21.postimg.org/r53e32hkz/stereowires.jpg

They ran their own speaker wire, and it's shitty dollar store speaker wire!

The group of wires near the top center of the image... where the hell do those run to?! The ends are taped off so they're still active apparently.

There's wire caps and a piece of household extension cord in there, just, GAAAAAH!!!

Anybody here good with Dodge Dakota wiring? Because this is a cluster fuck

Is the stereo and speaker wiring good in your other dodge? If so perhaps you can use it as a reference.

Many times, you can go to a place like Auto-Zone. They have the prints on their computer and can possibly run off a copy for you.

That larger bundle is the original speaker wires. Just match them up by color (violet solid, violet w/stripe is one speaker, brown solid, brown stripe is another speaker, etc). I am sure they aren't connected on the other end if they ran new wires.

The smaller bundle to the right is the original power harness (power, switched power, illumination, etc). You should be able to figure out what's-what with a test light.

I see hackjobs like this on almost every car I buy, lol.