'98 Ram 1500, 4.9l (I think). Have had it 5 years. ~165k mi. Now relegated to a yard plow truck, too rusty to pass inspection.

Last winter had intermittent starting issues. Bought a new battery, it cranks hard and fast now always. Last winter it seemed when it got real cold (below 30), it would crank but would not start. Sometimes it would sputter a bit after I released the key from the start position (but still ignition on). A few times it would suddenly start just fine.

Fast forward to now, the battery had been out of it all summer and used on my RV trailer. I put the battery in and the second I hit the key, it started right up. Pulled it out of the woods and parked it on my driveway figuring I'd do and oil change and (hopefully) it would be good this winter. Days later, tried to start it same thing. Crank all day long, no start. Sputtered a bit once or twice off start position and once coughed and chugged a bit like it was going to start. I put a timing light on one of the plug wires and could see that it was flashing regularly so I assume it is getting spark. I also seem to remember last winter pulling a plug, grounding and having someone crank it and getting spark also.

Had to move it, so had a neighbor help while we pulled with my Durango with a strap and tried to roll it back into the woods. For some reason, he hit the key at one point and it instantly started. It was pointed nose up then, like it is parked in the woods. Hmm. Fuel gauge shows 1/4 but it is flakey sometimes. So yes, I will fill the tank.

(thanks for staying with me this far).

So, I plan on spending some time on/under it next few days while it is still warm, looking for ideas on things to check. I have a scan tool, will probably look for codes. Seems like a fuel problem, I tried spraying carb cleaner into the throttle body a few times but it did nothing. Ideas on checking out the fuel system? I see that the fuel filter is in the gas tank. I HATE the idea of spending any money on this, but if this is a sign of failing fuel pump, I'll replace it. Any quick way to check for fuel pressure when it doesn't start? Could have pressure but ECU not firing injectors too I guess, how to check for that? Plugs come out dry when it is not starting.

Last question: Gear selector is "gummy", truck sat all summer, a bit hard to move it. When plowing, I use it a LOT. Lubrication points? I figure it is bushed up at the steering wheel somewhere and under neath??

And tip/ideas would be really appreciated. I will at a minimum replace the oil, filter and plugs, but I don't have a great deal of confidence in this truck right now and a non starting plow truck in an 18"+ storm really sucks.....

TIA

JH

 

You can rent or buy a fuel pressure gauge. There is a test port on the fuel rail. It really does sound like a fueling problem.

You can also get a 'noid light', just plug it in to one of the injector connectors, and if the pcm is pulsing the injector, the light will flash.

Does the fuel pump run when it won't start? (should be able to hear it.)

 

Thanks for the tips. So a day or two later, the truck suddenly doesn't start again. I ordered noid lights, got them today. Also downloaded a bluetooth ODBII app for my phone, have the ELM 327 module.

I do hear the fuel pump run as soon as I turn on the key.

My fuel pressure gauge does not fit on the port on the fuel rail. But when I push the pin the port center, some gas squirts out, so there is pressure.

I added 5 gallons to the tank, gauge shows that.

So I pulled #1 injector harness connector, and plugged in the noid light, used the fiber optic thingy that came with it, but saw nothing when I cranked the engine. Then, just for $hits, I jacked up the front of the truck, and disconnected the batter to install a quick disconnect switch, installed it then the truck started right up. CEL came on, OBDII showed injector open circuit error on #1. I took the fiber optic hood off the noid light and saw that with the engine running, it was blinking very dimly. Thought it was an LED but it is just a small incandescent bulb. VERY dim, but I could see it. So now I don't really know if it was coming on when the truck wasn't starting or not.

Last year, I seem to remember that I got it so start by leaving the battery disconnected for a while.

I cleared CEL code and it still starts right up.

For now....

Any other thoughts, stuff to check? Poor/voltage at the injectors maybe? Fuel pressure seems to be there, I might be able to get an adapter and actually read the value.

 

If simply resetting the PCM made it want to start again.... I would really suspect the PCM.

The dim bulb might be a lack of a good power feed, or, a poor ground.... or, just a weak noid light. Test a couple other injectors, and see if you get the same result. (they all get power from the same place though, so, may or may not make a difference.)

 

I'll stick my DVM on the harness, it has a "hold" function that will trap the highest voltage read. I presume that it should be 12 volts or close? Not entirely sure that resetting the PCM has worked every time. I agree that it may be a ground problem somewhere (how is the PCM grounded?). A mechanic cousin of mine says to suspect the Crank position sensor too, if it is not seen by the PCM it will not fire the injectors.

Any idea where I could get a wiring diag for this truck? Googled it, found a bunch, but most of the diags are not annotated and look to be for other trucks/engines.

Thanks again....

 

If the PCM doesn't see signal from the crank sensor, it won't fire the coil either.

 

Ahhh, ok, that makes sense actually. I found the ground wires in a diag for the PCM, I will see if they are solid and also look at the supply voltage into the PCM as well.

 

If that doesn't mention the grounds up by the power steering pump, take a look at those as well.

 

Ok, now this thing is really pissing me off. Today, not starting. Disconnected the battery for a while, then reconnected, still nothing. I put the noid on the #1 and #2 injector harness plus and it is flashing, and fairly bright. I put 12 volts on the noid in my shop, and the bulb at 12 volts isn't really all that bright anyway so I don't think it is a weak voltage issue at the injectors. And now, I do not get the timing light flashing when I crank it and it is not starting..... and I swear I did before. So probably have fuel but not spark.

And here is what is weird, as I said before, sometimes just after I let the key snap back off the starter, it sputters... the timing light flashes a bit then sometimes.... but not when I am cranking the starter.

What next to troubleshoot the spark problem? I realized that in all my year owning this truck I never had the dist cap off. Could it be an issue in there? I was thinking of putting the timing light pickup on the lead off the coil and seeing if I am getting spark into the dist. Could be the CPS also too I guess.

Thanks

 

Verify you are getting 12 volts at the coil while cranking. If thats good, retest for spark.

have you checked fuel pressure?