You have a smooth idle in a 3.9L ? There's got to be something wrong then..lol

 

Thanks for the replies.

Lastly, how quickly can the crank sensor fry out? Mine was just replaced 7,000 miles ago, yet the symptoms suggest that is the issue.

 

More than 7K ! Was it an aftermarket?

 

Thanks for the info on that TN. I will put in a new crank sensor tomorrow and see how it goes after that. I appreciate your help.

Jimmy

 

Yeah, it's not uncommon to even see a truck with a "no response" from a shorted sensor on the 5V circuit. Any of them can do it. Cam, crank, TPS, MAP, CTS, etc. Crank sensor is almost always the culprit.

 

My engine was rebuilt 7K ago, and the parts list says they replaced the crank sensor.
But I've had problems with them and wonder if they really did. ( They charged me for a differential seal, and when I noticed it wasn't changed, they said "Oh, well we didn't charge for other things, so we'll call it even) WTF

So I'm hesitant to take it back to them.

 

Wow............. I would never go back


Makes you wonder if they did rebuild it??

 

My truck drove fine coming home from work today but I did not make any stops along the way plus it was getting ready to rain by the time I got a few miles from home, so it was not as hot outside. Truck still ran well and idled very smooth, even with the AC on.

Tonight I picked up my new crank sensor at Autozone, they were the only place in town that had it in stock, even the Dodge dealer would have had to order it. I had a 15% off coupon I got in my email from Autozone plus I had a $20.00 store credit on my rewards card so I saved a total of $32.00. Regular price on the sensor is $79.99, it only cost me $52.75 including tax.

I also went to Harbor Freight and picked up their hand riveter with plastic rivets so I can put the fender liner back in after I replace the sensor. I used a coupon and saved a few bucks on the riveter too. I will tackle the sensor tomorrow and post my results back here. I sure hope this is all it takes to fix the problem.

Jimmy

 

3.9 crank sensor should be on the top of the bell housing. Lay over the top...

 

I went through the wheel well to R&R the CKP, it was just easier for me that way. Sitting on the floor is easier for me than laying over the engine or fender. I did find that the Autozone CKP has a much thinner mounting bracket than the OEM CKP so I could not re-use the OE bolts on the new one. The OE bolts are machined to an exact length for the thicker OE bracket so the bolt ends don't hit the flywheel. The upper CKP mounting bolt also butts right up against the block so you can't go back with just a shorter hex head bolt either, there is no room for a socket to fit in there. You can get a socket on the lower bolt without any problem. I needed two Allen head bolts about half the length of the OE bolt so I went to Ace Hardware and the guy there found exactly the bolts I needed plus a couple of washers because the heads were just a bit smaller. Ace pretty much has every bolt, nut, screw and nail known to man and the guy was very helpful and knew exactly which drawer to look in.

I will say it also helps to have a stubby 13mm wrench, a stubby flex head 3/8" ratchet and a 13mm Allen socket because you will need all of those plus a couple of regular extensions and maybe a 3/8" or 1/4" ratchet set to R&R the bolts. The stubby flex head ratchet came in very handy on the upper bolt. The Harbor Freight rivet tool worked perfectly except there are 10 POM rivets in the kit that are the right size for the mounting holes in the fender liner. The liner takes 11 rivets to hold it in so I used a plastic Christmas Tree push in fastener on the last one. I used a Dremel tool to sand down the end of the rivets that stuck out just a bit so I nor anyone else could get cut on one.

My truck is starting and running fine here in the garage, but it started and ran fine yesterday too so the only way I know to test it is to drive it. If it still has the stalling/no start problem after all this I am not sure what I will do. Either keep testing the system and trying new parts or maybe look at buying a new used truck. I really hope this new CKP does the trick. I will update here in a few days one way or the other.

Thanks for all the help on this.

Jimmy