1985 K-5 Blazer originally with a 305 – 4BBL Quadra-jet (17085226), Emissions UHK. I now transplanted a rebuilt 1971 350, using the starter, alt., intake manifold and carb. from the 305. Rotating assy, including new crank rods, pistons & rings, flexplate, and heads are from the 1971 350. I don’t have access to the ’71 intake and carb.

Problem:
Gas is making it to the filter inside the carb, but some solenoid or valve or something is stopping the fuel from going into the carb.

Engine will fire with ether.

No gas is spraying down the bores when moving the throttle cable.

Facts:
There is a sensor with two wires located on the pass. side of the carb., toward the front of the truck, right above the fuel filter. One wire comes from the harness to one side of the sensor. This wire is hot with the key turned to “ON”. The wire comes from the other side of the sensor and dead ends into some connection on the manifold (maybe a water jacket tap, but I’m not sure.) There were a few ports on the manifold that were plugged off on the ’85 intake manifold when I got the engine back from the rebulider. They didn’t say if I needed to do anything on my end to make sure the engine would run, regarding bypassing sensors for the ECM.

Questions:
1. Could this sensor prevent fuel from entering the carb if there is a bad signal either from the ECM or the other in-line solenoids, valves or sensors?
2. If it is possible, is there a way to either ground or provide 12VDC or a reference signal of 5VDC to the sensor to let the fuel pass?
3. What kind of trouble did I get myself into by using an early ‘70’s block? Is there any other things that I need to do in order to “trick” the EMC, i.e. bypass the knock sensor, EGR, TPS, IAC, O2 or any other systems Chevy implemented?

you sure the fuel filter is on right and it isn't plugged?

Have you replaced it?

First thing I checked after making sure the pump was OK...

Did you replace it?

I replaced it and tried it without a filter, no dice. I did actuate the solenoid at the carb., on or off, it didn't make a difference. I called the rebulider and he took the carb back and will have one by Monday that will work with my application. Thanks for the response, I will post back and let you know what the rebulider says. Thanks..