I just changed the crank senser it ran fine for about 35 mins then the tac started to jump all over then it flatlined.. It started this morning and now it wont start at all.. If i start it with either it fires off then dies directly after. While cranking on it the tac is constantly jumping.

 

DO NOT USE ETHER

I understand that it will take out the grid heaters and do other damage.

Otherwise I have no suggestions other than maybe the crank sensor is bad or improperly installed. I'm sure someone on this site will be along shortly to assist you.

 

ether no good

 

Engine speed and crankshaft position are provided through the CKP. The sensor generates pulses that are the input sent to the Engine Control Module (ECM). The ECM interprets the sensor input to determine the crankshaft position. The ECM then uses this position, along with other inputs, to determine injector firing sequence and fuel timing. The sensor must be powered up by 5 volts to operate.

The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it.

The engine crankshaft is equipped with a bolt-on tone wheel. The tone wheel is equipped with 35 teeth and a gap where the 36th tooth should be placed. This missing tooth indicates to the ECM the relative position of cylinder #1 to the Top Dead Center (TDC) position. This does not mean that cylinder #1 is at TDC. When the CKP is aligned with the missing tooth, the missing tooth is 60 degrees away from cylinder #1 TDC position. The teeth cause pulses to be generated when they pass under the sensor. The pulses are the input to the ECM.

Sounds to me as like you have installed a bad sensor or improperly installed it.
Scan for codes and get back with me.

 

I recently replaced an oil pressure sensor that did something very similar. When i looked at it closer, it appeared that the terminal pins were slightly smaller than the original ones. I suspect they were not making good contact at the connector. Check the connections. Ether and grid heaters make a dangerous combination.

 

If your going to use ether UNPLUG/UNHOOK your grid heaters. If you got to use ETHER on a Cummins there is something wrong!

I would back track and check and make sure you got the sensor in correctly. Check you connection that its clean and tight. Like someone said above check for codes and see if there is something else causing you problem.

 

For what it's worth, check the fuel shutoff solenoid and relay for proper operation. You did just do some repairs which may have caused the problem, but it may be circumstantial too. If the fuel relay (electric and a dodge part) goes bad it will cause the fuel shutoff relay to not pull in (not energizeing the start coil) so the fuel doesn't get turned on. the hold coil will still energize. crank the engine then with the key still on check the lift pump- it should be retracted, if not lift it manually (it will stay) and try the key again. if it starts that's your problem.
The culprit there could be the shutoff solenoid or the relay- the service manual should have diagnostic info for the solenoid. Mine had this problem but only when it was below freezing- the relay was factory defective and the previous owner and his dealer never figured it out.

Always make sure you have the basics for combustion- fuel, air and ignition- in a smoker we only need to worry about fuel and air, so fuel supply is always the first thing to verify, then look for electrical and computer problems.

 

....that's soooooo 12 valve!

I'm too scan tool dependant to give you the info you need, but you do need a 5V supply from the ecm and that should be present with key on. Sensor ground is usually bk/lb in wire color and the other of course is the signal wire. It has happened, try to be sure the tone wheel isn't loose.

 

There is also the possibility the tone ring has come loose and damaged the new sensor. If you still have the one you replaced, look at the end of it and see if it looks like it has been rubbed on. If it has, you're ring is loose. I have heard of three instances where the ring has come off and broke the crankshaft, so if it's loose don't delay fixing it!

Kim

 

oops, didn't know there was any difference in the fuel supply circuit. Sorry to but in.