I need help with a 99 Dakota 4x4 w/3.9 V6 & 5 spd. Somtimes it runs great and then it will start cutting out/******* and start shaking very bad . Hasn't died, but does loose power for about 10- 12 miles, then somthimes it clears up and runs fine for while longer. I have had it to 3 different shops and had the following replaced:
- spark plugs ( at least 3 sets)
- spark plug wires
- fuel pump and filter
- cam sensor
- crank sensor
- battery
- coil ( twice)
- fuel injector for cyl #4
- computer ( from salvage yard)
I really like the truck, but it has just about broke me! Any body have any thoughts ( besides setting it on fire)?

 

Check the Idle Air Control Motor valve. It is mounted on the back side of the throttle body. If the pintle end of the IAC has black crusty junk on it, clean it off with a rag soaked on carb cleaner. Don't drop it or handle it roughly or you will need a new one. A bad IAC can cause a rough idle and/or stumble problem. Even if you do need a new one, they only run about 30 to 50 bucks depending on where you buy it.

Jimmy

 

Thanks for the tip, I will take it off tonight and check it out.

 

Replaced the IAC ( looked really bad)and thought it was fixed. Ran great about 7-9 miles, pulled over, shut off the motor, started it up and it started cutting out again. The tack shoots up when it does this and two of the rotors that I replaced looked like they had been hit by an arc welder. Any other ideas?

 

With all the things that you replaced the one thing that I would look at is the PCM from the junk yard. It may be bad and causing bad timing problems with your ignition. That is the only thing I can think of that could burn rotor buttons and cause the RPM and tach to freak out like that. And if the PCM doesn't work, the truck won't run. The other things you replaced, you can get by with even if they are bad and the truck should still run, if at least poorly, even if the parts are bad or performing poorly, like the IAC, plugs etc.

I would definitely check with the junk yard about swapping out the PCM. There is a place here in Florida where I live that sells gauranteed used PCM's. I don't know the name of it but you might Google Florida and PCM to find it.

This to me sounds like a really bad PCM. Others here may have more info and ideas on it. Have you had it scanned and do you have any trouble codes stored? Autozone and Advance will read codes for free, unless you are in California. Advance has a half price sale on code readers right now, and Harbor Freight Tools has good prices on them too.

Jimmy

 

I have had is scanned many times. Several codes are common:
crankcase sensor ( replaced)
cam shaft sensor ( replaced)
misfire in cyl 4 ( replaced injector, compression is about 19% lower than other cyl's)
Is there any way to test my ECM? What I can't understand is how the truck runs great for several miles and then will start cutting out . It just seems to happen at random intervals and then will eventually smooth out and run good again.

 

First a bit of history / background...

I have a '95 Mustang. The '94s and '95s are notorious for this exact problem. Drives great initially, then runs like crap when it gets warm. Sometimes they will run fine, then sometimes they will suddenly die on the side of the road and not start for 30 to 40 minutes. In those cars, the problem is related to the PIP sensor.

This part is also known as a pick-up coil, stator, or hall effect sensor. I don't know much about the distributor in the Dakota, as I have never had a problem with it, and I have no idea if this is something you have already changed that just goes by another name here in Dodge world, but the symptoms sound identical to me.

The thing about this part is that it controls or interacts with just about every other part in the car. Not being so sure about the computer programming in the Dodge, I don't know if that is the case here as well, but it seems likely to me. In my car, it interacts with the fuel pump, the injectors, the EGR, the timing - I literally mean everything in the car.

Just a wild stab in the dark, but your situation just sounds so much like what so many people that own cars like i have experience that I thought I would throw it out there...

PS - I would appreciate knowing if this part does in fact have a different name in Dodge talk. I have generally always heard it referred to as a stator or pick-up coil, but if it goes by another name, I would like to know that.

http://shop.advanceautoparts.com/web..._673765242___#

 

I guess the Dodge dealer can check the PCM with the DRB scan tool. Or an auto electronics/starter-alternator repair shop might have the diagnostic tools to check the PCM. I think you need a DRB to really find out what's going on with it. I am no expert but to me it still sounds like the PCM is bad. What did the spark plug from cyl #4 look like? If it looked OK I would still suspect the PCM. I guess it is possible both the crank shaft sensor and cam sensors were bad out of the box, but I doubt it.

Jimmy