Crank but no spark

[GlamRam99]

1999 Dodge Ram with 5.9, less than 100K miles. I changed the battery, now it cranks but no start/ignition. I dont have a OBD scanner but maybe parts store has one to borroww? Never did this before. I think it jas to be something easy but weird. Any ideas? Like to fix myself if I can.

 

[Fast69Mopar]

1999 Dodge Ram with 5.9, less than 100K miles. I changed the battery, now it cranks but no start/ignition. I dont have a OBD scanner but maybe parts store has one to borroww? Never did this before. I think it jas to be something easy but weird. Any ideas? Like to fix myself if I can.

I'm assuming this is a 1999 Ram 1500 with a 5.9 Magnum gas engine. With a crank/no start condition the first thing to check is spark coming from the ignition coil. Remove one of the spark plug boots and install a spark tester or go old school and stick a screwdriver in the boot and hold it close to a bolt on the engine and have someone crank the engine for you. If you see a spark jump from the screwdriver to ground the coil may be okay.

If you don't have any spark coming from the coil check the power and ground to the coil. If no power and ground to the coil make sure when you turn the key to the run position, without cranking, that the ASD relay is being powered up in the PDC or Power Distribution Center.

Next, check to make sure you can hear the fuel pump come on when you turn the key to the run position. Remove the fuel cap and listen while someone turns the key to the run position. These are simple things that can be done without a scan tool.

 

[GlamRam99]

That is exactly what I was gonna do is check about spark at the coil after doing some research. I do hear the pump come on right away when I turn the key. A friend gave me a scan tool and hope it does the job, an OBD-2.
Yes, forgot to mention engine size, a 5.9.

Thanks for your input. Much appreciated

 

[GlamRam99]

Well, I put a new ignition coil in and STILL it just cranks. A friend borrowed me his scan tool but it has no instructions. Now, I need to find his on the net. What I found is a little different than his. Still, the saga continues. It's gotta be something simple.

 

[Badger 13]

It sounds like a bad ballast resister from the old days. Not sure if they had them in 1999 models.

 

[Yeret]

I have owned cars/trucks/SUVs/quads/riding mowers, either carbureted or fuel-injected. All but one case I've ever had of a crank/no start condition was fuel-related (the sole exception was my dumb butt screwing up the spark plug wire order). Not saying that's exactly what you've got going on, but in my particular case, that's been the most frequent cause.

Have you verified fuel pressure? There should be a valve on the driver-side fuel rail where you can attach a fuel-pressure tester. Hook it up and turn the key to the key-on-engine-off position. If you're reading zero, the fuel pump isn't working. Probably an issue with the pump itself, but it certainly could be an electrical issue. Either way, fuel pump/related wiring is where to start.

If the tester is reading significantly less than spec (I believe it's 45 psi, but I'll hope someone else can confirm this), you're looking at either a weak pump, clogged fuel filter, faulty regulator, or, again, faulty wiring.

Where things can get tricky is if the crankshaft position sensor is going out. You can be reading fuel pressure just fine with key-on-engine-off, but as soon as you start cranking the engine, the ECU waits for a signal from the crank sensor to re-energize the fuel pump (KOEO, the ECU runs the fuel pump for a second or two, then opens the circuit until it receives a signal from the crank sensor). If you have a helper handy, you can have them crank the engine while you observe the pressure tester. If the pressure jumps to 45 psi KOEO, but starts declining while cranking the engine and it doesn't fire, the fuel pump isn't re-energizing, hinting (although not definitively) pointing at the crank sensor

Crank/no start can be a real PITA since there are literally a hundred things that can cause it. Fuel injection can either be easier/harder to diagnose depending on your experience, but in the end, all engines need fuel/air/spark. Hope this helps!