98 Ram 1500 won't start, has spark.
 

Hello, I am a newbie here so I hope I am posting in the correct place/manner. As the title states I have a 98 Ram 1500 318-5.2 4x4 Laramie. The other day I drove it to a friends house to drop something off, left it idling in the driveway for about 5 minutes, when I came out the truck was off. I restarted without any problems, but then the RPM dropped from about 1k to about 300-400 when I tried to accelerate it simply died. I was able to restart it a few times with the same thing happening. Now however it won't start at all, just keeps cranking. I have spark as tested with a clip-type spark tester adjusted to about 28-30 also the coil is at 9.17 ohms for primary and about 13.32 ohms secondary which I believe to be within specs. I smelled fuel from exhaust pipe but I don't know if that really means anything or not... The truck was throwing an intermittent code for O2 sensor but that should only prevent it from running great right? Would it be possible that it is trying to lean it out too much? I'm not sure about all the possibilities with these trucks, I bought it about 4 months ago from the original owner who is a friend of mine. Have been replacing/repairing things as available and as needed. But hadn't done any work for about 2 weeks when this happened 3 days ago. Any input would be greatly appreciated! Also, what would be the best way to test to see if the fuel is there or not?

Which O2 sensor? If its the rear one (downstream, or post-cat), it might mean the cat is clogged, which would possibly cause your issue.

For future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html

The cat was another culprit I was considering, if it ends up not being the main issue I do think it will be going out soon anyhow. I did hear a little rattle that I have heard is often associated with a bad cat. I had autozone check it a while back and at the time I didn't know much about the layout mechanically of the truck. He said it was the upstream O2 but he pointed to what actually is the downstream. So a bit of confusion in that but he did mention that he thought the cat would throw its own code but again that's why I'm here asking people who actually know what's going on and not relying on their good intentioned misinformation. I will check the code again tomorrow, but just out of curiosity, would that give out all at once, or would there likely have been symptoms (maybe I didn't notice) that would help diagnose? Also, I just might have gotten some new info, I had my brother push the intake Schrader valve in the fuel line by the intake manifold while I both had the key in the run position, cranked over the motor. In both instances not a drop of fuel came out of the valve. Would this be a strong indication that the fuel pump was shot or could there be another explanation? Thank you!

Will it start with your foot on the gas? And a simple way to check the fuel pump is to turn the key to the run position and you should be able to hear the pump kick on..

No, it won't start if it's floored or if I pump it etc. I didn't hear the fuel pump kick on either. Would there be anything else you could think of besides the fuel pump relay and the pump itself that would prevent the pump from turning on?

Only thing besides pump failure could be wiring... If you said there was no fuel at the rail then I would suspect the pump has failed...

If you are getting spark, then its not a PCM problem. Check and see if you are getting power back to the pump for a few seconds when you first turn the key on. (requires two people...) If you get power, bad pump.

Ok cool, thanks very much! I will check into it tomorrow, we will have it up on the lift tomorrow morning. Will write back to let you guys know what I came up with.

HeyYou what about the ASD relay?? I have never had an issue with it but it pops into mind.

He is getting spark though, so, that means the ASD relay is actually working. (It powers the coil, and injectors.)