no feul to the engine on 1990 GMC 3500 Pickup

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keeps blowing the computer fuse without the key on and no feul to the engine. Will start if dump gas down the carb 1988 vandura 3500
(1) Answer
You will need to find the cause of the fuse blowing. I am assuming it is the ECMB fuse blowing. My wiring diagram show that fuse sending power to the ECM, oil pressure switch, and fuel pump relay on an orange wire. You will need to inspect the wiring to each of those components and look for damage which could cause the fuse to blow. If the wiring all looks OK, disconnect one item at a time and see if the fuse still will blow. Another posibitlty is the red wire to the fuel pump prime connector is grounded, check that wire from the connector to the fuel pump relay.