Why is my truck fuel injectors not pulsing?

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TimThomas

New member
I have a 91 Chevy K1500 with 5.0L, A/T. It was running rough, and then one day just shut off and wouldn't start. Had it towed, and they replaced the distributor. I replaced all spark plugs and wires, distributor cap, and rotor. This got the truck running temporarily. Same problem. Changed the fuel pump, and got it to run for a day. Then shut off again and will not crank. Bought a kit to exchange all the gaskets on the TBI, and found the the fuel pressure regulator spring was broken. Obtained a new one off of ebay. Truck will still not start. It crankes, but no fuel is coming from the injectors. When I check the wires with multimeter, I get 12 V constant to one side and practically nothing on the other side when trying to crank. I have also replaced the ECM and all vacuum lines. If I spray carb cleaner in the openings where the gas should spurt, it will crank, but only for a second.

The truck is worth more to me than it would be to dispose of or sale. Hopefully someone can please help.

Thank you, Tim
 
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doornobk

New member
Assuming you have fuel pressure and spark that sort of leaves you looking at maybe the TPS (throttle position sensor). If the computer thinks you are flooring it and the engine is not running it shuts off the injectors to clear a flooded condition. It can be tested with an ohm meter. Its on the side of the throttle body opposite the throttle linkage. Other thought would be the map sensor but it does not seem like that could totally shut down the fuel.
 
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