Dads truck shuts off while driving

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Sep 27, 2015
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Alabama
1999 Dodge Ram 1500 5.9L 4x4 approx. 190k

Dad told me the other day that his truck has started to randomly shut off while driving. He said there’s no shutter or surge like it’s struggling it just “shuts off like a tv” at any and every speed. I called him today to check on if he had gotten it seen about yet(he hadn’t) and he said he had to run into to town to pay bills which is about a 15 mile round trip and it took him 3 hours to get home once it started shutting off on the way back. He said he has to wait up to half an hour before it will start back up once it shuts off.

My first thought was fuel related, but he said it doesn’t skip or surge like it’s not getting enough fuel so I think it’s spark related. What do you guys think?
 
I'd start with checking the fuel pressure. It's not a carburetor so it won't spit and stutter as the fuel level drops in the bowl. With fuel injection the system requires a minimum amount of pressure to operate properly.

The two simple tests would be with a fuel pressure gauge on the fuel rail and a spark tester on coil wire and also on one of the plug wires. It's not a COP system (coil on plug) so it still has a distributor, cap, rotor, coil and plug/coil wires.

So check the coil and fuel pressure. You'll likely find your problem hiding with one of these systems.
 
Check that one or more of the ignition wires ISN'T touching the exhaust manifold and burning & shorting out. This is exactly what happened to my buddy's '97 RAM. He kept towing it into the local shop($90 a pop) just to have the tell him they couldn't find anything wrong. I found it! :)
Look for any worn(burnt through) ignition wires that maybe have drooped down onto the manifold.
 
I had an 87 3800 powered Oldsmobile that would seem to burn through ignition modules. Had the exact symptoms verbatim as your dad's truck. I kept replacing it with aftermarket parts from Chief Auto Parts. If I knew then what I know now, I would've used an OEM dealership part.
 
Crank position sensor in bellhousing or there's essentially a cam position sensor in distributor.

Carry a code reader and look for both stored AND pending codes NOW and when it actually happens. Some report only getting a PENDING code when the problem is present.
 
Crank position sensor in bellhousing
and those were terribly unreliable.

OBDII live rpm should read about 200 while cranking. If it reads zero the crank sensor is probably bad. This test must be done during the time while it will not start.
 
When I saw this topic I wondered if it was going to be a Chrysler product.

My friend had an almost new K-car that did the same thing. As he said, "It would die in full flight. What kind of car does that?" The dealer had several chances to fix it but nothing worked. It just kept dying. And it would die at the most inopportune places - like in the middle of a busy intersection.

He traded it in on a Toyota Corolla and never looked back. He was an older man and a western history buff who drove all over and literally wore out vehicles. He wore out several Corollas. He died recently at 97.
 
I wonder if he can hear the fuel pump whirring in the tank when cycling the ignition after a stall.

Hard to say. I think everyone's contribution to this thread is valid.
 
OBDII live rpm should read about 200 while cranking. If it reads zero the crank sensor is probably bad. This test must be done during the time while it will not start.
If the truck has a tachometer it will not move when attempting to start the engine if the crank sensor is bad. This is what would happen when the crank sensor needed to be replaced on my Ford 7.3L diesel. I kept an extra in the glovebox because of this as it happened several times.
 
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When I saw this topic I wondered if it was going to be a Chrysler product.

My friend had an almost new K-car that did the same thing. As he said, "It would die in full flight. What kind of car does that?" The dealer had several chances to fix it but nothing worked. It just kept dying. And it would die at the most inopportune places - like in the middle of a busy intersection.

He traded it in on a Toyota Corolla and never looked back. He was an older man and a western history buff who drove all over and literally wore out vehicles. He wore out several Corollas. He died recently at 97.
Ford, when they hired Team TFI engineers who figured a bunch of thin, laminated layers responsible for ignition and mounted in a hot area was a great idea.

Ford even managed to garner a lawsuit over the extraordinary design. I'm sure they were very proud of this accomplishment.
 
A bad ignition switch will sometimes have that exact symptom. I've had it happen to me in a few different vehicles over the years.
 
While an engine can run without a cam position signal, it will immediately stop without crank position to determine first cylinder and RPMs.

A bad fuel pump can manifest as a surge or no start. My non-tech brain says spark is going out. You need data from a scan tool or at the least a fuel pressure gauge to condemn the ignition system.
 
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