My first post here! After a couple days of getting no-where I'm turning to the experts (you guys!) I've had a freakish amount of bad luck in the last week. My car's injection pump died and I'm waiting on a salvaged one and I have been using my truck to get around. And now its stranded too! And I start a new job tomorrow... :/

Here is a brief bit if history. 97.5 Ram 3500, 12v cummins with a flatbed and 130k miles, Truck is from the south west, I live in upstate NY.

For the last year and a half every once in a while (maybe once every month) after it was hot, say at the store or something it would refuse to start. It would turn over really strong but just not catch as if it it was being told not to electronically. Or if the fuel was simply shut off. I would just have to wait between 1-20 minutes and it would start on the second hit. It was annoying, but its not my daily driver so I've just dealt with it assuming it would be easy whenever I got around to it.

The last couple months it seems to have started doing it more often. It will always start giving enough time waiting. But definitely annoying, always happening at the worst time. My car died a couple weeks ago and using the truck more often has made it much worse. And now after a whole day (yesterday) of off-and-on between work trying to get it to start it just refuses too. Even when cold (40F).

Its not even at my house, it decided not to start at a house I do repairs at and had left it overnight. So its blocking this woman's garage. I am going to get a ride back out in 4-5 hours, and take my big battery charger and some tools and do anything I can. If I can move it in the next day or two I'm going to have to have it towed because I don't want to burden the homeowner. Its really quite embarrassing.

I've disconnected the battery negative and waited. Taken out every fuse/relay I could find. Checked all connections (but forgot the lower chassis ground. I even gave it a wiff of ether when I was running out of light and getting desperate. That actually just makes it harder to start. I don't want to damage my starter. I did not have a wrench handy to crack a injector line so I don't know if its getting fuel when I'm turning it over yet.

I have a friend who is a heavy equip mechanic that doesn't often working light trucks (always works fine when he borrows it...) but he suspects something like a relay or the like that gets hot and sticks.

What can I possibly try to diagnose it? It ran fine 2 days ago. Infact it runs really good otherwise. I love this truck and I've invested a lot of time into it and want to keep it for the long haul. Its got really low miles. But I'm at my wits end and don't know what do.

What do you think? Thanks in advance!

 

sounds like your shut down solinoid isnt operating correctly, try starting, if it wont try to pull up on the shut down lever and see if it moves, if it does something is wrong with the solinoid or the relay that controls it, with the key on you should beable to pull up on the lever and it will stay in the up position, then the engine will start

here is a crude pic but it is the solinoid and the lever is at the bottom

 

@dodgetrucker75


That was it!!!!! This issue has plagued me for a long time and I thought I was finally up sh*t creek so speak! I still have to isolate if it is the solenoid itself or if its perhaps a relay that controls it?

With the key in the ON position the solenoid is still stuck down. When I pull it up it stays up and then I can start it. And it starts up on the second hit.

Any advice on the further troubleshooting?

Now i think I may have angered my starter with all the cranking the last few days. Now it wants to click sometimes...

 

the way to isolate it.... there are 3 wires to the solenoid, ground, power with key on, which we know these two are ok because the solenoid is holding, the third wire is hot while cranking only, find that wire, put a voltage tester on it and crank the engine, if it has full voltage on the wire, change the solenoid, if it doesnt have the correct voltage, go after the relay system

 

My generator has been down for a few days and i only have nights to work on my own stuff with work right now so I have not been able to figure out what is the culprit yet.

This thing has always stalled really really really easy when it first starts. It takes a minute or 2 for that to smooth out and the rpms to increase at idle. Is there a way I can adjust the idle to say increase it 50rpms or so? so that its a little more stable when its cold? I looked all over for some type of a adjustable linkage, governing screw etc etc.

 

a low idle will definitly cause a cold stall, idle should be around 800-850 rpms, here is a pic of the left rear of the injection pump, turn the low idle to get it where it should be

 

Testing the pull circuit of the fuel solenoid is quite easy. Follow the wiring harness from the solenoid and disconnect the 3 pin connector. On the solenoid side you will have 3 wires; Black=ground White=pull and Red= hold. Those are the wire colors on mine. Your's should be the same. Since the hold does work you need test only the pull circuit.

On the truck side connect a voltmeter to the center socket. Have a helper turn the key to start, the engine will crank but not start. Each time the key is held to start you should read battery voltage.

If no voltage you have a bad relay, a wiring problem or no feed from the starter solenoid feed wire during the start sequence.

You can check the operation of the solenoid. Connnect a ground wire to the pin for the black lead on the solenoid side. Connect a thick wire to battery positive. Now quickly touch this wire to the pin for the white wire. The fuel solenoid should pull up. Touch the pin only briefly as this is a high amp draw.

The solenoid and linkage could be dirty and need cleaning and lubrication. I had that problem. I would have to pull the solenoid on manually. Cleaning and lube fixed it.