Why do I suddenly have no injector pulse?

Difficult to do with a common rail diesel without diagnostic equipment and some expertise.

The main problem is the electronics will not allow fuel injection to begin until from the start of cranking a minimum fuel rail pressure to be achieved in a certain time - so if nothing else is found; battery, starter, good cranking speed, blocked fuel filter, air leak in fuel line, etc., check electrical pulses are being sent to the injectors with noid lights. If there is a pulse the injectors should be removed for testing but if there is no pulse it would be better to call in a specialist to test the electronics and the high pressure pump.

Perhaps there is no injector pulse on your truck due to an none-injector electronic fault or perhaps there isn't enough pressure building in the common rail to tell the injector pulse to begin.

strong start weak run indicates a power loss during the run cycle
Try changing the ECM with a known good unit as it may have an electronic failure internally
If you have problem cam or crank sensors, normally it will not allow spark for the engine to run

run the fault codes and check for problem ECM
There is an electronic component failure in the injector circuit that when over heats , shuts that injector circuit down
try replacing the ECM with a known good unit

blown fuse. ; is first, as per always.
2nd is scan it, did you scan it yet? that is always 2nd.
all efi engines, all ECU , all cut injectors for (noid lamp test dead?)
you said pulse,does that mean fuel pulse or electronic pulse to injector coil..... ? all injectors dead. or just 1. same for spark.
toss coin land, noid dead. all noids
loss of. NOID signals.!
1; spark
2: lose of CMP or CKP signals (cam or crank senders)
3: ecu sees wide open throttle it cuts fuel 100%
4: ecu bad, is CEL lamp dead key on? scan it.

When you unplug all of the injectors, are you saying you have battery voltage on one side but nothing coming from the computer on the ground circuit ? 6 and 8 cyl engines are connected in series, such as odd cylinders are grounded at the same time on some models.

The injectors will have power on one side and its the PCM that sends a ground pulse [signal] to the other side. Did you unplug the injector connection and check for the ground pulse while cranking the engine or back probed while cranking or running? I would unplug the connection and check that way if you have not. If you still do not have that ground pulse then you should be able to find the same wires at the PCM and check for continuity along the wires for the two cylinders.
The ignition module sends a signal to the PCM which tells what injector to pulse. The ignition module also works with the distributor. You may want to look inside. Perhaps some strange thing happened to the relucor inside.

The injectors recieve a signal from the ecm or electronic control module to fire the injectors. It does this by recieving various inputs from different sensors. If any one of these input sensors goes bad them the ecm will not know which injector to fire at the right time. Unfortunatly diagnosing the problem involves some test equipment such as a noid light to see if you have injector pulse. fuel pressure guage to see if you have fuel pressure and a scanner to check the inputs to the ecm. You may want to take it in to at least have the diagnosis done since not too many backyard mechanics have these tools available. Depending what they find wrong with it you then can decide if you want to tackle the repair yourself or just let them do it. Good luck hope it works out for ya!

The ECM or electronic control module does fire the injectors, however, the injector pulse that the control module uses to fire the injectors is generated from the igniton module inside of the distributor and then the injector pulse is processed through the control module.

Most likely the ignition module that is inside of the distributor is faulty, or there is a damaged or grounded wire between the control module and the control unit. If there is no problem to be found with the ignition module inside of the distributor or with the wiring between the control module and the ignition module inside of the distributor, then the problem will be with the electronic control module itself. Also, check all of the fuses to the ECM.

Let me know if you require any further assistance.

hello sir,

absence of ground pulse means there is some kind of shorting circuit in your control circuit.

which can make the ground pulse to get shorted there itself preventing it to reach the circuit properly.

thank you

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good day