Archived No Start!! Need Help A.S.A.P.!

[78cummins-wagon]

i have a 94 2500 CTD, auto, with 3. 54's,and pretty much everything is stock. i was trying to trouble shoot my trans problem (no overdrive, but the TC locks up fine) when one of the three wires (on the trans, above the nutral safety switch, 3 wires in the plug, one being pin 54 on the pcm, controlling TC lockup) shorted out and caused the truck to die instantly. its now in my drive way useless and i need it this weekend. any ideas?? any help will be greatly appriciated!! i have tried all of the fuses, and all the under the hood fuses too. i am at a loss and i desperately need it for work!!

 

[Missouri Mule]

Is the starter cranking the engine or the engine just not firing up?



The only thing on the trans on a 94 that will keep it from starting is the neutral saftey switch.



Make sure your fuel shut off solenoid is pulling up and staying up, if not firing up.

Check to see if you got a ground at starter relay (via neutral saftey switch) if not cranking.

It mite be the ignition switch/wiring if it stalled immediately but also fuel shut off solenoid.



PCM does not have anything to do with starting or running the engine!

 

[78cummins-wagon]

the truck cranks fine. it will starfor a brief moment and just shut its self off within 1 or 2 seconds. if i look at all the gauges they all work with the exception of the tach, with does not move what so ever. i dont think its the fuel shut off selonoid, bucause the truck does start, then it gers shut off by something (cps?) i'm not sure and i'm not to firmilliar with this truck. nay more ideas??

 

[78cummins-wagon]

held shut off selonoid in the up position and the truck started, but had no tach. any ideas??

 

[Missouri Mule]

No tach could be caused by the engine speed sensor located on front engine above vibration damper. The connector to engine speed sensor is infamous for the pins to be dirty or bent/loose which can cause stalling , loss of tach plus a few other things such as the PCM uses data from ESS for shifting into overdrive. Make sure connector is cleaned and no bent/loose pins make sure you have 5 volts going to ESS and ground wire is good. You should have volts going back to PCM but don't know how much.



When you held rod up for fuel shut off solenoid did the engine keep running?

Did you release rod to see if it stayed up and engine stayed running?



What are trying to check out is the "Hold up coil" your pull up coil is working because engine starts.

There are 2 coils inside of the fuel shut off solenoid one is the hold up coil activated by the ignition switch when in run position. The other is the pull up coil activated when ignition switch is in start position. When start is released pull up coil is turned off. Pull up coil has relay actually two relays the starter relay( turns on fso relay) and the fuel shut off relay sends power to the pull up coil. The pull up coil is good!



If engine stayed running while rod was being held up but shut down after rod was released you need to find out if there is power getting to hold up coil if there is power getting to solenoid you will need new solenoid. If power is not getting to solenoid you will have to trace it back to igniton switch.



Just turn igniton to run position and use test light or multi-meter to check for power. You have three wires going to the solenoid one of the wires will be hot the other is ground (which you know you have since the pull up coil works) the other wire with no juice will be the pull up wire. (Don't remeber the color of the wires sorry).



Hope this helps you out.



Let me make it clear the Pull up coil only pulls the rod up while the igniton is in start postion. The hold up coil keeps the rod up after key is out of start position and in run postion.

 

[78cummins-wagon]

now what. TC does not stay locked when you let off the petal even with the mystery switch engauged. installed new pac brake and cant figure out how well it works ith out the tc staying locked... any idears??

 

[wcjp]

Is the tach working yet? Have you checked the Crank Position Sensor (CPS)?