Maybe 4 times in the last 12 months, my 2001 Ram 1500 Sport has made a sound kind of like it backfired through the intake while starting. A couple of those times, it was a bit slow to start on the second try.

It did that yesterday morning. However, this time it didn't start on the second try (or any other).

It has fuel. There is a smell of gas, the plug I pulled was wet, and gas shot from the Schrader valve.

It also has spark. The spark from the coil was weak and yellow, so I replaced it on general principles (it did not help).

My searches on the forum indicated it might be a timing problem and that replacing the cam position sensor would be a good try. I did that yesterday and also replaced the distributor cap and rotor while I had it apart. No joy.

Today, I replaced the crankshaft position sensor (just now got done). Yeah, I'm pretty bitter over that thankless, hand cramping job and I would like to personally counsel the engineer that came up with that location. No success from that either.

ETA: No CEL and no codes.


What's next?

 

Did you check spark at the plugs or the coil?

I had the wire from the coil to distributor go bad and give me fits.

 

I checked for spark at both the coil and one of the plugs.


The only thing that seemed a little unusual in my activities was that the new distributor cap was *very* hard to get on. It took a lot of down pressure on it to hold it in place so that I could get the screws in. I chalked that up to the new rotor button and the new rotor.

I have never replaced a distributor on a 360 before - if it should have went on easier than that, please let me know.

 

+1 to newman. Recheck that stuff. Sometimes seating the plugs on the cap....they don't get fully seated b/c of the location behind the keg.

Additionally, when you changed the rotor...you were sure to put it on the same way? Just thought to ask even though its only one way.

Other options to check out:

1. Ground wires, two up on firewall (passenger and driver side) underneath the weather stripping. Passenger side one has couple leads, PCM and to back of valve cover. Also ground up on front driver side right next to power steering.

2. Clean the IAC. Be gentle with that thing. Find the DIY for that in the FAQ/DIY Subforum.

3. Have you checked the condition of the plugs? Reseat them, including the wires.

 

Why not eliminate the possibility of the timing chain, disconnect the ign coil by unplugging the 12v supply plug, remove the fuel pump relay from the pdb, remove the dizzy cap, have someone in the truck to turn it over, see if the rotor turns. Also check the timing marks on the harmonic balancer to the number one spot marked on the dizzy housing they should match up when the motor is at TDC on number one cyld. I would also do a comp test at this time to see if you have a hung intake valve.

Download the fsm in the diy area and it will help you with these tests.

 

Plugs were wet? Have you replaced them, or, at least pulled 'em and cleaned them? Had a look at the temp sensor on the intake manifold? (coolant temp) Check your oil, see what the level is like, and what it smells like.

 

I carefully noted the position of the rotor and replaced it in the same position. That was pretty easy to keep track of since it was pointed straight back at the firewall.

I will check the timing chain tomorrow evening (unless I can find time tonight).

If the chain has enough slack, is it possible for it to jump a tooth or two? This is the original chain with 156K on it.

 

HeyYou: The oil level is good, but it is due to be changed - I just haven't had the time. The plugs need replaced and are also on my list of things to do. However, I have never had worn out plugs take an engine from running fine one day to dead the next.

It does have a coolant leak somewhere (for about 3 years now), but I have never been able to locate it.

 

Gas fouled plugs won't spark. At least, they won't ignite the mixture. If the coolant temp sensor has failed, the PCM thinks its bitter cold out, and will DUMP gas..... flooding the engine in short order. (and fouling the plugs....)

 

I'm gonna go out a limb here and say the cat is clogged.