Afternoon everyone,

Last week, I encountered a gas pump with a bad shut-off valve that overfilled the tank on my Ram 3500. I didn't encounter any adverse problems with it until I filled it up at my usual station (stopped at first click) and went to leave. It would fire up, but wouldn't idle. I managed to feather the throttle and head on down the road without any issues. Once I was up and running a little bit, it would clear up and idle. If I stop for a few minutes, I have to start the whole process over again. I figure one of two things is going on:

First, I suspect that the evap system is flooded with raw gas and needs attention. I've worked on a lot of things, but evap systems are one I haven't had much trouble with so I could use some pointers on where to start figuring this out.

Second and totally unrelated to the over fill, I've noticed that the truck sounds like it's cranking slower than normal recently. I know that if the charging system isn't up to snuff, the computer can have problems at idle. I have a spare alternator sitting on the shelf so that can't be it (because it's never what you have a spare of), but I'm wondering if the battery is part of the problem.

Thoughts?

 

No codes are being shown? You could check the evap cannister to make sure. For your starting problem you could get a load test on the battery at a local auto parts. Check the battery terminals for tightness and corrosion. On my truck I have added an additional ground wire from the starter mounting bolt to the battery negative, at bit of overkill, but the starter does draw a lot of juice. I even managed to shorten the positive cable a foot. I also have brass battery terminal clamps.

 

Check the line going to the intake from the purge valve, gas in there? Bits of charcoal? Also check the line from the vapor canister to the purge valve, same check. See what ya got.

 

Thanks for the pointers. I'll check for codes and see if there's anything in those lines.

 

Sorry for the late update...

After finding no codes but evidence that gas had been in the line from the canister to the purge valve, I picked up a replacement evap canister not long after my last post. Since the weather has been miserable and I had not been having much trouble with the idle, I procrastinated about changing it out. I finally got around to replacing the evap canister while I was under there draining the oil today. Right off the bat, I noticed that its idling a bit smoother than it had, but the real test will be on the next warm day we have as that is when it seems to be having trouble stalling out.