DustyCO

First time posting in here, please be gentle.

Just bought my 03 5.9 the other day and now it won't start. It will crank and crank but won't kick over.

Did the code reader thing and got a P0839, which is the 4wd switch circuit high voltage.

is this a common problem with an easy fix?

I have done some searches and had little luck. If it is common or easy fix, I would rather hear from people that know more than me. My guess right now is that it is a sensor on the transfer case but I don't really want to go and start replacing parts if it won't fix the problem.

Thanks, Dusty

Mexstan

Do you have a fuel pressure gauge on it?

In all probability that code is a red herring and has nothing to do with the no start situation. Without a fuel pressure reading, my guess is that you just lost the expensive injector pump. Second possibility is that the canister mounted fuel pump has died. Can you hear the pump when you turn the key on, but without cranking?
Place a can under the fuel drain and turn the key on. Now open the drain valve and see if fuel just dribbles out or comes out under pressure. If there is no pressure, then it is the fuel pump. If there is pressure, then maybe the injector pump.
If it is the fuel pump, then maybe now is the time to consider an after market pump. Also add some gauges.

Let us know what happens.

DustyCO

Thank you, I will give that a try.

I am working today and will get to it tomorrow afternoon. I will keep you posted on how things are going.

I was going to replace the fuel filter anyway because I don't know how long it has been. So I already got some tubing and 1" 1/8 socket, (think that's the size) to do some work in that area.

Mexstan

If you are very, very, very lucky, it is only a plugged fuel filter, but will not hold my breath. Don't forget that before trying to start it after the filter change to cycle the pump at least 3 times. This will give you a good chance to listen if the pump is working.

Maybe a silly question, but you do have at least a 1/4 tank of fuel?

DustyCO

Again, thank you for the advise, and it is not a silly question, because I'm sure that has been the problem for someone at one point in time. But unfortunately it is just over half a tank. I know the gauge is right because I put $50 of diesel in it yesterday. Only drove about 30 miles.

Please keep the advise coming.

rockcrawler304

When you drain the filter housing you should get about12 to 14 ounces of diesel out. If it is less than that you probably have a bad fuel pump.

After the filter change and figuring out if the pump is working or not we will be able to give a lot more advise.

BTW.... Welcome to DTR!!!

DustyCO

Pleasure to here, and quick update.

So drained fuel filter, put a tube on it and into a bucket and turned the key, seem to be getting decent pressure out of the pump.

As I have only had this truck sense Saturday, and it wouldn't start on Sunday, I called the dealership that I bought it from. They ran me through a few tests and finally decided to send a mechanic out to look at it.

He hooked up a diagnostic tool and nothing really showing why it won't start. So it will be getting a ride to the dealership for more tests, best guess right now is fuel pump isn't strong enough or bad injector.

Mexstan

Keep us posted on the cause of the problem. If you are lucky it is the injector pump and the dealer installs a new one free of charge for you.

soulezoo

Dusty, welcome to DTR.

As you have what amounts to a 12 year old truck now, some things are bound to occur.

First, the Common Rail (the "fuel tube" if you will that the injector lines hook to) has a pressure sensor. That sensor has to read a minimum of 3000 psi of fuel pressure before the ECM (computer) will allow the injectors to fire. Some common causes for that lack of pressure are:

A worn out pressure relief valve (PRV)
A failed CP3 (injector pump)
One or more leaky injectors
A cracked fuel line (a common occurence- but you would see fuel leaking)
A poorly seated crossover tube (unlikely)
Or a failed Rail Pressure Sensor


There are other possibilities, but those are the more common ones.

Good Luck!

DustyCO

Thanks again for the hospitality,

Yes this is an older truck and I knew full well that I was getting something that was going to need a little work. I greatly appreciate any and all comments/ advise.

From what I am reading, the CP3 injector pump is a bit of a pain on these 03's. I have no idea if or when it was replaced.

I have also read and heard that people have changed a fuel pump from external to an internal pump inside the tank? Is that the CP3 pump or another one?

The dealership said they will take care of this problem, but I am still wondering what other things I should keep my eye out for or fix before it becomes a problem.

Things on my list so far,
1. Water pump
2. Figure out fuel pump
3. Do a good shake down of steering components.

Please give any advise for more.

carl48

dusty the the cp3 pumps are very reliable and probably never need to be changed. the common rail is like no other injection system used in the past and virtually nothing used to troubleshoot previous injection systems applies to the cr. you tube has a great 4 part video you need to watch. we run a fleet of dodges and have our own shop and got our first 03's in 02. the bad filtering caused many injector problems and before long we understood the system better than the dealer mechanics. the lift pump on the 03 came out mounted on the filter canister, most failed under warranty (all of ours did) and were relocated to the tank we have had zero failures in the tank ones. the lift pump supplies approximately 6 psi to the cp3 if you look at the front of the engine you can find the cp3 on the right side just below the valve cover. there is two wires connected to the fca valve on the cp3, this adjusts the cp3 pressure to what the ecm asks for. at idle you see about 7,000 psi power you may see 28,000 psi surges. this go's to the common rail that has all of the injectors connected to it, the prv and the fuel pressure transducer, the pressure is on the injectors all of the time. the injectors are popped off by electrical pulses from the ecm. this answers #2. you need to add better filtering to prolong components, you can get about four times the life out of the injectors by adding the 2 micron filter. it took Chrysler ten years to figure this out and add it to the newer trucks. pm me if you want a how to for a $100 kit you can make and install in an hour. as for #1 i have never had a failure as for #3 that is a weak point. go to genosgarage.com and download there catalog or get them to send you one, they sell only the best and only for dodge and have the cheapest price. you need to fill out your sig so we know how your truck is set up, this helps us answer your questions. i usually take pictures of most failures and can post them to help. here is some, the 03 dropped a valve seat and the Chevrolet cp3 is paralleled with the truck cp3

DustyCO

Just to let everyone know, #1 injector was bad. Dealer fixed it, and I'm back on the road.

Mexstan

Thanks for the update. This helps the next guy that has a similar problem.