I have a 3116 Cat with a 40 pin ECM that will not start. I know it is very rare for a 3116 to have a ECM, and at first I even thought it was a 3126. But it is a 3116 serial #8WL02985 which you can comfirm with your Cat dealer was ship with Electronic Injection.
Now for my Problem. Pulled onto the job one day with load of hot asphalt. Noticed truck running like crap although ran fine there. Managed to keep running long enough to unload. Brought back to shop on tag trailer. Truck would start but would not idle or stay running. Pulled primary fuel filter and sure enough, half full of nasty looking water. Checked filter on motor, looked ok, and replaced both. Primed system, turned key. Worst than before. Check fuel pressure, None. Replaced fuel pressure regulator on back of head. Got fuel pressure, still will not run. Load back on tag trailer take to local shop. Local shop say injectors only getting 9volts, ECM bad. Find used ECM and send to Cat with mine to have Programmed. Pulled, cleaned and painted motor and frame because of rust while ECM was out. Put all back together.
After I put engine back in, it would not crank over. I noticed the shifter display for Allison tranny was not lighting up which would cause neutral safety switch to keep starter from cranking. Bypassed ignition and motor cranked. Found power supply to trans and bypassed. Cranks over now, and still won't start. Getting power to pins 6 and 28 on ECM plug. Getting no smoke from exhaust why cranking which tells I'm getting no fuel, which makes me think injectors are not firing. Still don't understand why I lost power to trans because it was working fine before pulling Engine. Took picture of all battery connections before disconnecting and cleaned all connection and new grounds. Part numbers on ECM's match, but could one ECM be for standard trans while other for automatic?
If I'm getting power to pins 6 and 28, and grounds to pins 4 and 5. Which I am. She should fire off. I got no codes that would indicate a bad HUEY pump. But this no power to Trans is a mystery, and check engine light does not come on when I turn ignition switch on. But everything else seems to work fine.
Any help would be appreciated.

Any Body???

Check all grounds are same as you did the power?

I check all the grounds, and even ran a new ground to engine block. ECM is grounded directly to battery. And checked voltage from pins 4 and 5 to pins 6 and 28 and getting 12+ volts. Could there be a ground in the harness some where that I'm missing that got pushed back into the casing when moving the harness around to get engine in and out?

Are you getting 12v to the fuel shutoff solenoid on the pump?

This 3116 is not a mechanical fuel injection system. It is a electronic fuel injection system with 40 pin ECM and HEUI pump. I'm almost positive there is no fuel solenoid shut off. Fuel gets shut off when the injectors get shut off. But it would not be the first or last time i am wrong. where would this solenoid be?

On the high pressure oil pump.
It should be getting 12v.
I think it's called an "activation solenoid " but I'm out of town.

I'm getting 4.5 volts at that solenoid with ignition on. looks like those wires have been spliced a couple times.

The part number on those ECMs could be the same but there are still programmable options in the configuration file which are truck specific , some configuration file options can energize and de-energize certain pins depending on application. When you took them both to the dealer to make them match they would have needed to install the proper flash file as well as going through the configuration file line by line to make sure all the settings are the same. I have also had ecm failures that causes a loss of configuration settings, which makes it a guessing game with the replacement ecm.

As for the HEUI system I would pull one of the plugs in the high pressure oil rail of the cylinder head and check for metal in the oil that runs out. If there is metal in this oil, the pump is failing and has likely pushed metal into the injectors causing damage there as well.

A crank but no start could also be that the ecm is not seeing engine speed, check the connections on the speed sensors, not exactly sure where there are at on a 3116 but likely reading off of the camshaft gear or crank shaft.

Hope this Helps
MZ

It started. And now it won't. I check the Check Engine light bulb the other day and found it to be missing. Picked one up from Napa. put bulb in, turned on ignition, after a few seconds I heard click come from engine compartment. Did not pay much mind to it. But I cranked motor to check bulbs and engine started. Turned off quickly because valve cover off and god knows what laying on it. Clear anything from motor that might do damage and went to start it again and no start. Proceeded to scratch head. Waited and then turned on ignition, and waited a few more seconds and heard click again, cranked motor and it started. Ran fine, checked return fuel flow, good. Check fuel pressure, good. everything seems to be fine. Switch off. Won't start again. could of swore the clicks came from around the intake heater relay. Can't be sure because can't get that click to come back. Would drive off cliff if only could get started, and not a lot of cliff options in south jersey anyway, but do have a big *** ocean and a lot of short piers.