Cause of injectors not working?

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Galane

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Location
Idaho
First Name
Gregg
Truck Year
1982
Truck Model
Sierra 3500
Engine Size
350
I've installed new injectors, new fuel pump regulator diaphragm and spring, swapped the 1982 tank for a 1987-1991 Suburban tank and pump.

I have fuel going to and through the regulator, enough that it's soaking through the gasket on the throttle body.

I have power to and through the injectors, checked with a test light to ground.

But no fuel ever sprays out of the injectors on this 1991 TBI setup. The donor truck ran well, despite the rusted and broken regulator spring.

I don't have a tach wire on the coil, no tachometer in the 1982.
 

89Suburban

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Southeast PA
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Paw Paw
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2007
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Engine Size
5.3, 4WD
Power to the injectors is constant hot and ECM grounds the circuit to open the injector. There is a TBI fuel system troubleshooting chart pinned in here somewhere.
 

4WDKC

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Southern Florida
First Name
Kacy
Truck Year
1987
Truck Model
V10
Engine Size
350
I've installed new injectors, new fuel pump regulator diaphragm and spring, swapped the 1982 tank for a 1987-1991 Suburban tank and pump.

I have fuel going to and through the regulator, enough that it's soaking through the gasket on the throttle body.

I have power to and through the injectors, checked with a test light to ground.

But no fuel ever sprays out of the injectors on this 1991 TBI setup. The donor truck ran well, despite the rusted and broken regulator spring.

I don't have a tach wire on the coil, no tachometer in the 1982.

My 93 had a similar problem where it wouldnt start, had fuel pressure but would fire the injectors. After months of messing with it I started disconnecting 1 sensor at a time till it started and ran. The TPS sensor was telling the ECM it was at WOT while starting and gm coded the ECM to not fire the injectors while cranking for flood state.
 

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