Hello all and thanks for looking. My name is Josh and I'm from south Mississippi. I have a 99 Durango with the 5.9 in it. I'm fairly good with working on vehicles I'm also employed at Oreilly's so dealing with parts and problems is an everyday deal. I've been brainstorming with guys at work we've checked a lot of things out and still haven't come up clean. Here's the deal:

Truck can be cruising at any speed, any rpm, idling, driving, anything and it will randomly just die. When it does die it will not start up immediately after. I have to allow it to cool down for no average time. It's taken 2 minutes to 2 hours before it would start up again. SO I thought fuel pump. Changed that...nope. Then I though ok maybe it needs a tune up since we did just buy the truck not too long ago and really don't know the history all too well. Changed plugs, wires, tps, air filter, fuel filter, oil/oil filter, map sensor, cap, rotor, and ignition coil.
Still does it. So now I'm thinking could be one of the crazy sensors that I'm just not thinking of. Oh and by the way...No check engine light and I know that it works because when we first bought the truck it was on for an EVAP code...maybe someone left the gas lid off or didn't screw it down tight enough...it hasn't come back on since.

So I got to thinking what sensors could be faulty and not throw a code that could relate to this problem...Crank Position Sensor is all I can come up with...changed that then. Still doing it. Fuel pressure is fine, spark is fine when it is running.

I got to thinking well its only doing it after it has been running for a while at least 15 minutes or longer. Or if it has idled for a while 5-10 minutes. So that made me think well it could be getting too hot and maybe I was unaware that dodge has it to where if it gets too hot then the truck will automatically shut off before it explodes. Check fluids, changed thermostat, changed belt, and now I'm stuck because I've changed almost everything and I'm getting close to over $1000 $2000 if you include labor at which I did all myself. I am down to this one last sensor...the stinking Cam Position Sensor. Just a little advice for anyone going to purchase one of these from a parts store..they will not show a listing for it in their computer systems as a cam sensor, rather as a pickup.

Before I change this part and disassemble the upper distributor again, I want to inquire from someone who is willing to help, if this does not fix my problem...before I run it off a cliff or into the river or use it for a 50 cal target practice...what else could it possibly be?!

I forgot to mention one thing that struck me as odd...and this is a question I'm still looking for an answer too...when the truck does die...the RPM needle stays where it was last reading at. Which sensor reads the RPM...I was thinking Crank position sensor but it could be the cam right?

I know I have typed a short novel and I appreciate anyone who has read this far and is willing to lend some advice. Thanks again

Josh

 

Welcome to df josh just and idea though have u tried pulling the throttle body off and cleanin it with TB cleaner or carb cleaner and a toothbrush also clean the iac valve i had the same problem with mine and did that fix and it worked like a charm

 

First off, welcome to DF, second judging by your avatar you are a marine?? if so, thank you for your service..

This issue brings to mind one thing.....

Next time it shuts off take a ice pack and place it on the PCM. if after a short period it starts again then you PCM is getting to hot and is shutting everything down... i remember the 99's being notorious for the overheated PCM but, that is commonly a summer issue but, looking at the weather map it looks like MS is seeing upper 80 temps...

HTH

 

Something else you didn't mention is attention to the battery?
I would clean the terminals down and either clean or replace the connectors and see what happens there...
Also +1 on the PCM. I am lucky in that I removed the stock air box and have opened up the intake there. Caused more cold air from outside to come in and keep it cooler in there. I would suggest that if it is your PCM.

 

definitely sounds like the PCM is overheating and shutting down causing the truck to shut off.

 

the sensor that gives your spedo a reading is your transmition speed sensor. its located on the bottom tail section of your tranny. a 5min fix. look for metal shavings on the end of it. also your pcm sounds like a likely culprit or a faulty ground check all your grounds for a solid frame connection. and cudos on being in the marines. its always nice to meet a fellow devil dog. ooraa!!!

 

the transmission sensor wouldnt cause the speedo to simply read high, that would be whatever sends the signal to the dashboard, once again points to the PCM, that sensor wouldnt cause any of these problems

 

Thanks guys for responding and the welcomes. And Semper Fi to my brother. And thank you for your support.

You know the PCM did cross my mind a few times and I guess it was just wishful thinking that it couldn't be the problem. But seeing as everyone is jumping on board with that idea. I will definitely look into that.

Someone mentioned the battery. It has an outstanding battery in it. Over sized if anything 1040 CA. Terminals are all fine and clean with protection on them. The PCM overheating theory is a very good one. Even though south MS is in the upper 80's that mixed in with the humidity and a hot motor could definitely cause it to get some extra heat that would cause it to shut down as mentioned. I figured there was a transmission solenoid that read speed but I was also thinking that the crank or cam position sensors also played a part but I could be very well mistaken. I will be looking into a modification to the PCM to keep it cooler. From what I can remember (I'm not looking at the vehicle right this minute) but the air filter box is located right in front of the PCM so maybe installing a CAI to open up the air flow some more would help. I'll also run an AC vent towards it haha I wish.

Again thanks guys I will keep it posted when the opportunity arises.

 

PCM most likely I had that problem myself. I bought a Mopar Performance PCM and had no problems after that.