Mystery Shut Down 2001 Dodge Ram 1500

dodge

#1

My 2001 Dodge Ram decided to not start at some point this winter. After jumping it with my car it ran for a while but once I shut the truck off it would not restart. Thinking this a battery issue I went to auto zone and purchased a brand new battery with high cold crank amps. Upon instillation the truck tries is hardest to crank over. I waited until the next day before call a tow truck to bring it down to the local shop. For kicks and giggles I tried to start it and low and behold it fired right up. I let it run for ten minutes and did a test drive around the block. Right as I made it to my driveway it shut down with no warning clunks or sounds. I got it towed to the local auto shop and they were able to replicate this issue. However, they tested the fuel pump and other systems and even though they were not receiving power they were still cycling properly before and after the shut down. They said it was a computer issue so I towed it to a dodge dealer. They hooked it up to the computer and found nothing wrong nor can they replicate the issue. I am at a loss here. I use it to haul wood and pellets but I do not trust it to drive anywhere when it will randomly shut down. All the sensors have been tested and are in working order and the computer is fine. Any thoughts?


#2

When the shop tested it in the “no start” condition, was there spark? If not, one possibility is an intermittent failure of the crankshaft position sensor. These can go bad intermittently and will cause the engine to shut off and not start at random. Often changing out the crank angle sensor will fix a mysterious shutoff problem like this, even if the sensor “tests” OK most of the time. It’s the random intermittent times that it cuts out that cause the problem.

If you want to do more diagnosis on it, here’s how:
http://troubleshootmyvehicle.com/chrysler/3.9L-5.2L-5.9L/crank-sensor-diagnostic-test-1

But it’s an inexpensive part, easy to replace, and sometimes cheaper to just go ahead and replace it than pay someone for more diagnosis…especially when they tell you the sensor is OK even though it may not be.


#3

I find too many things about this post to be completely unclear to be able to say anything.

It “decided not to start” but then you jumped it but then it wouldn’t start again. During those initial no-starts was the engine turning over or not?

“tries its hardest to crank over” is also ambiguous. Was it cranking very weakly? Sounding like a weak battery? Or was it cranking over vigorously - as it would with a strong battery? Note that “cranking over” is just that the starter turns the engine. It has nothing to do with whether the thing actually starts or not.

Then this one is the most perplexing: “However, they tested the fuel pump and other systems and even though they were not receiving power they were still cycling properly before and after the shut down.” If they were not receiving power, then there is no way they could cycle properly. So I can’t tell what this means.

Off-hand - this is a Dodge, so it probably has an ASD relay (Auto-Shut-Down). Find another non-essential identical relay and swap it in. And it is having intermittent problems - inspect your main power cables. Pull and clean ALL main power connections and pay special attention to the grounds.


#4

it was not turning over but it was cranking over vigorously. Thank you both for your help and suggestions. I will check it out and get back to you.


#5

If you need to come back and report a no start again, note that “turning over” and “cranking over” are the same thing. Use “wouldn’t fire up” for cranking/turning well, but not actually starting. It helps avoid the confusion.


#6

This will be difficult to fix until the problem can be narrowed down to either spark, fuel, timing, or compression. Since it seems to run ok otherwise, I’d focus on the first two as the likely culprits. Spark is usually the easiest one to eliminate. There are inexpensive spark testers available that produce a visible flash if the plug is firing. I’ve used a timing light as a quick check to see if there current going to a spark plug too.

If you don’t have time to monkey with this yourself, you’ll probably need to find a shop that will be willing to keep the vehicle for a few days or weeks. Maybe one of the techs there can drive it home after work and bring some diagnostic equipment in the trunk. Eventually it will fail and then they can narrow it down.


#7

Have a friend with an identical problem on his Dodge,this post helped me( and I hear some Bigshots mixup turning over and cranking ,so thats not an issue with me{some were grammer Nazis too}-Kevin