Hi all:

This is my first post to this forum. I just purchased an '01 Ram 1500 with the 5.2L V8 and 4wd. The engine starts OK, but then after a few seconds stalls, and I can't restart. If I let it sit for a day, I can repeat pattern.

Any thoughts on what to check first?

Al

 

o2's?
my guess.
wait till someone with a little more mechanical knowledge chimes in

 

sounds like fuel or a spark problem. When it won't start, check for either of these conditions being present or not.

 

I'm gonna take a guess and say fuel pump maybe. How many miles on the engine? If you have a good spark, then I'd be suspecting the fuel pump. Post your diagnosis, plus a bit more info about the truck, if you can, and we'll go from there.

 

if it starts there a spark....check and see what kind of fuel pressure you get...

 

OK, thanks for the suggestions.

Tomorrow morning will do a couple of things: 1. Add five gallons of gasoline to the tank, to confirm that its not a lack of fuel in the tank causing the problem....the fuel gauge reads about 2/3 full right now, but I suppose it could be malfunctioning. 2. I have a simple spark tester that is used by disconnecting a spark plug lead from a spark plug and running through tester (which looks somewhatlike a spark plug itself, but which has atoothed clamp to attach to ground) to see if I have spark.

Aquestioncomes to mind -padodgeram, or others, what's the easiest and least expensive way to check fuel pressure? I assume I need some sort of fuel pressure test kit, and the knowledge of where to attach it...I'll check my Haynes manual to see what it says.

The truck has about 150,000 miles on it. High mileage for an '01 model year.

 

i had a 97 fullsize with the 5.2. one day it was running fine then it crapped out. would start for 5 seconds then stall. dealer had to replace the crankshaft sensor. problem fixed. this sensor is what controls the timing for the injectors to fire. common problem. they get crude on them and thats it.

 

Well, your description sounds like an exact match to the symptoms I'm observing....I'll read about crankshaft position sensors in my Haynes manual as well. Thanks for the tip.

 

OK, I didn't do some of what I said I'd do....but I did read through my Haynes manual about the crankshaft position sensor, and confirmed that it is one of a series of sensors that provide input to the PCM (powertrain control module), basically the brains of the truck....And, from my reading, it appears that any of anumber of conditions will cause the PCM to shut down fuel and ignition systems, making the engine stall, and I think, hard to diagnose, as when, for example,the ignition system is shut down by the PCM, I assume that I will not observe a spark at the cylinder, but I might incorrectly assume that there is a problem with the ignition system (i.e. coil, distributor, spark plug wires, etc.) when in reality the lack of spark may be caused by general shutdown by the PCM. Make sense to any of you?

With the crankshaft position sensor, it is apparently easily diagnosed through the OBDII interface, but requires an OBDII compliant scan tool. I did some research on these tools, and found several choices - some simple code readers at about $50, but decided to spend a little more and purchased the ElmScan 5 at a cost of $125. In conjunction with the laptop I already have, I am hopeful that I'll be able to diagnose this andother problems with other modern vehicles.

And then, I tried to start the truck again. Oddly, it started, and ran for as long as I needed to drive it. Given I didn't change anything, I am thinking that the problem will come back, and when it does, I'll have the ElmScan 5 to diagnose it.....

 

"When trouble-shooting and unsure of the problem, ALWAYS start with the cheapest stuff FIRST"

So before you do any of that, I'd make sure the air filter is good and clean.
Either install a new one OR just remove the old one and re-try the procedure with the filter out of the way.
If same result, oh well, cheap way to figure out air is NOT the problem.

You might, just for kicks, replace the fuel filter next.
If you get nowhere, at least that maintenance has been done (as most vehicles have 50-100k+ on a fuel filter) so it sure won't hurt to replace something that most likely is well over due.

Then, replace cap and rotor (but at least check it).
Yes I know the cap + rotor is a PITA so maybe do it while you got the air filter thing off.
While you're at it, spend the extra $5 and get the High Performance one.

I doubt it's the plugs or wires, if it starts and runs and then shuts off...
But it could also be the coil, if you have a spare one sitting around...