First off I'm new here but hope I can contribute in some fashion as well, 2ndly I hope everyone had a very merry Christmas. 

Now the truck then the issue. 1998 24v 3500 4x4 manual transmission. Mods are air box, full exhaust, hot rod vp44, air dog 2 165, edge juice CS w attitude, and the wiring harness mods listed on here. 

Ok now my problem.... driving the truck one day and it shuttered out of the blue didnt think anything of it and kept on going. A few days later it does it again and the tack dies, doesnt come back and I notice the levels on the edge dont work anymore and the truck is running bone stock. No codes or check eng during this time. Picked up wife to run some errands stopped by the auto parts store wouldn't crank back up. P0336 showed up so walked back in the parts store got a crank sensor slammed it in and truck fires up tach is back for about 30 seconds truck runs rough tach dies motor smoothes out. P0336 code is there. Shut truck off,  restart same thing starts right up tach is up for maybe 30 secs then dies and truck smooths out. So what I have done..... I removed both ECM and PCM sent them both to be tested. ECM was bad so replaced it. Removed all wiring from the engine bay, undressed it cleaned each and every connector and fixed all the grounds. Ohm'd out each wire from start to finish and validated no brakes or anything else wrong with the wiring. Put it all back together and still the same thing. I forgot to mention I have changed the crank position sensor 3 times and the cam position sensor once. I have come to the end of my rope. I would greatly appreciate some advice. I have followed every step of troubleshooting I can get my hands on. Hopefully it will be something stupid, if it is I will gladly put on the dunce hat.

 

Quick note I forgot to add that is important I think. The Edge display I have set up to show RPM and it never drops to zero it is following the engine and is correct. 

 

Thanks in advance 

Alton 

Edited December 26, 20186 yr by Alterego
Add info

@Mopar1973Man it is the original block in the truck no motor or cam change. It just happened one day. Drove to the store, truck wouldn't start, grabbed a CPS and changed it truck started but tach died thought is was a bad CPS changed it again same thing. Sent ECM off to have it tested was found bad, changed ECM now 3 times and the same issue. Didnt realize the reluctor ring was able to move or I would have checked it. Truck ran fine until this event. The reluctor ring is the last part of the equation. I was looking at the other link you sent me with the swap problems and saw the 36 minus 1 external pickup I'm going to give them a call in the morning and see if that will replace the internal ring. If it does I will go that path till I get time to go into the motor and reset the internal one. 

2 hours ago, Alterego said:

@Mopar1973Man it is the original block in the truck no motor or cam change. It just happened one day. Drove to the store, truck wouldn't start, grabbed a CPS and changed it truck started but tach died thought is was a bad CPS changed it again same thing. Sent ECM off to have it tested was found bad, changed ECM now 3 times and the same issue. Didnt realize the reluctor ring was able to move or I would have checked it. Truck ran fine until this event. The reluctor ring is the last part of the equation. I was looking at the other link you sent me with the swap problems and saw the 36 minus 1 external pickup I'm going to give them a call in the morning and see if that will replace the internal ring. If it does I will go that path till I get time to go into the motor and reset the internal one. 

 

And you said SAI tested the 3 ECM's?

@pepsi71ocean yes SAI electronics did test my original ECM. They do not sell replacement parts so... I started looking and found automotive module source.. I ordered a replacement and same issue so I assumed by everything I heard that ECM was not right, so sent it back got another and still same thing. The 3rd ecm came from a friends truck that I swapped in to see what would happen. I do have to say AMS didnt give me a single issue swapping out the ecm and did everything they can to make sure it was right. I know the ECM they sent me is good because it runs great in another truck. I've think with the help of this forum, it has been narrowed down to the tone ring on the crank. I'm going to explore an external option and completely remove the internal one completely. 

What a lot of work your going thru to find the issue. Before dropping the oil pan, isn't there any other possibilities for something simple?. Anything can be easily overlooked.

 

Yesterday I was messing with the two alternator leads, the black two pin connector on the Nippon Denso. After disconnecting I noticed a lot of black dirt on the face of the connector which can cause, sometimes called, 'Earth leak' across the pins. Cleaned up the face and blew air inside around the two pins, inspected where the factory put hard bend on the two wires at the connector, (looked like the insulation may have deteriorated, couldn't tell for sure, so I taped them anyway separately at that bend and placed lots of dialectic grease on the face and around connector. Plugged back in, started the truck and seemed to be running surprisingly better.... smooth as glass really.

 

I know I'm shootin from the hip w/o any practice here but I'm hoping it something simple.

Edited February 4, 20196 yr by JAG1

6 hours ago, Alterego said:

@pepsi71ocean yes SAI electronics did test my original ECM. They do not sell replacement parts so... I started looking and found automotive module source.. I ordered a replacement and same issue so I assumed by everything I heard that ECM was not right, so sent it back got another and still same thing. The 3rd ecm came from a friends truck that I swapped in to see what would happen. I do have to say AMS didnt give me a single issue swapping out the ecm and did everything they can to make sure it was right. I know the ECM they sent me is good because it runs great in another truck. I've think with the help of this forum, it has been narrowed down to the tone ring on the crank. I'm going to explore an external option and completely remove the internal one completely. 

 

So does SAI rebuild computers then? Or what exactly do they do?

@JAG1 first off all input is much appreciated. I know sometimes as a life long mechanic we tend to dive right in and overlook the obvious. To answer your question yes sir all connections have been checked cleaned and "bond checked" to their respective components. All the harnesses have been removed disassembled inspected cleaned checked end to end for any failures, then reassemble to aircraft specs all bend radius of wires have been set to 6D or better. Then everything was loomed up and taped all the joints that could have been an issue have been changed out for solder sleeves then adhesive heatshrink on top of that. It has come down to the last thing in the equation, which is the tone ring. I wasnt aware it was a bolt on ring until @mopar1973man brought it up. But with the logic of the ECM and a signal that doesn't agree with the other inputs. I'm confident that once I drop the pan I will either find pieces of the ring in the bottom or the small removable section sitting there. I will post pics and updates once I get into the bottom end. Once again thanks to everyone for all the information and input 

Ok everyone so after getting the oil pan loose enough for me to see inside the tone ring is broken. It has sheared in half. So got a new tone ring and will post pics once I get the pan off 

I'm glad you found it and that Mopar Man was able to help with this.  

12 hours ago, Alterego said:

Ok everyone so after getting the oil pan loose enough for me to see inside the tone ring is broken. It has sheared in half. So got a new tone ring and will post pics once I get the pan off

 

Bingo. Gotcha! 

 

Old tone ring out. I'm not sure what happened and I am very lucky that there is zero damage to anything inside. I hope this is a one and done deal. 

Looks like the insert came out and rest got damage as it got slung off the crank. Make sure you index that gap section right.

Edited February 16, 20196 yr by Mopar1973Man

Do you have any suggestions on the installation. I'm trying install without pulling the crank. I've got the cap off but there doesn't seem to be a way to install it without pulling the crank 

Edited February 16, 20196 yr by Alterego

Did you find the rest of the pieces?

Is there a way to get around not having one? Some kind of a fooler on the sensor? You can hit me if it's a dumb question 

Yea I got all the parts in the bottom of the pan. Everything is accounted for. The issue now is getting it back on without pulling the crank 

@JAG1 I have tried to find a way around it with no luck. Destrocked diesel has a 35 minus 1 tone ring kit that mounts to the balancer but According to them it wont work as a replacement for the internal ring 

15 minutes ago, JAG1 said:

Is there a way to get around not having one?

 

No. Engine won't run without a tach signal.

 

16 minutes ago, JAG1 said:

Some kind of a fooler on the sensor?

 

No. There is no way to fool the crank sensor.

 

16 minutes ago, JAG1 said:

You can hit me if it's a dumb question 

 

Naw... I'll drop a bolt in your manifold... 

Found it in the ram forum.... You have to pull #6 main bearing cap off, then pull #6 rod cap off. You might have to rotate the engine to get the cap off. The ring is in 2 pieces with 5 screws holding it all on. Take the small section out first, then rotate the engine so the gap where the small section was is facing up. Then you have to manipulte the large section out.  Assemble in reverse order...The tone ring screws torque to 71 in lbs...and use blue loc-tite on them. Main bearing cap...45 ft lbs, 66 ft lbs, then turn bolts 90*. Rod cap...22 ft lbs, 44 ft lbs, then turn bolts 60*. Oil pan bolts 18 ft lbs. I'll let everyone know how well it works out hopefully will be up and running by lunch tomorrow... 

@Alterego could I get you to write an article about the tone ring install? I'll make it worth your while.

@Mopar1973ManWill do. This has been a huge learning experience. And I will gladly share anything I can 

I'm glad Mopar Man not close.... you'll have all the bolts to complete the job.

Edited February 16, 20196 yr by JAG1

10 hours ago, JAG1 said:

I'm glad Mopar Man not close.... you'll have all the bolts to complete the job.

And all this time I thought you were the bolt napper.