Originally Posted by Ded0nfeet
I know some part of the system is working because the injectors pulse when the dist is turned, is there anything that would cause the spark to be intermittent?
Absolutely. I have seen ignition control modules do exactly what you are describing.
The pickup coil signal gets handed to the PCM to run the injectors VIA the Ignition control module. As it passes through the Ig control Mod it is shared for the start/run circuitry in the Ignition Control Module to run the coil. After the engine starts a 5 volt signal switches the ignition trigger signal to a different circuit in the Ig Control Mod so the computer can regulate ignition timing , injector pulses are regulated by the raw(basic) signal from the pickup coil via the module. Somewhere in the module , the handoff circuit for the spark is failing.
Unless you can get the Ignition Module tested to be for sure it is bad or not,you will have to replace it. I have seen this paticualer problem several times on the TBI setup your truck has.
Oh and to be safe , I allways put a new Ignition coil in when I replace a module, because I have seen coils have a high voltage leak (spark shorts out) and it will kill the module.You can start with a coil, but chances are if it is shorting out the high voltage spark, the module took a hit allready.