87 Buick V8 307 Stalling after driving 20-30 Minutes

NO spray? It's either a failed (or missing) carb plunger pump check ball that won't seat right, a worn/split carb plunger pump diaphragm. Possibly an outside chance of a very low float level issue or combination thereof. Something is hindering the carb plunger pump.
Thinking about getting rebuild kit for carb.
 
Thinking about getting rebuild kit for carb.
Check the fuel pressure while driving first. If the pressure is low, you can rebuild the carburetor as many times as you want. It won't fix your problem. Did you replace the TPS or did somebody else? Did you replace the airhorn gasket or reuse the old one? If you reused the old one, you may have caused other issues if it's torn or leaking. You can unplug the TPS and the MC solenoid and the car will still run, although not very good so I doubt the TPS had anything to do with your original problem. What was the TPS voltage before you replaced it? That code could have been set by someone unplugging the connector with the car running. The voltage needs to be checked from closed throttle to wide open throttle, with the engine not running. It should read from .5v to about 5v without any opens through the full range, but a faulty TPS in a carbureted engine won't cause it to stall.
 
Check the fuel pressure while driving first. If the pressure is low, you can rebuild the carburetor as many times as you want. It won't fix your problem. Did you replace the TPS or did somebody else? Did you replace the airhorn gasket or reuse the old one? If you reused the old one, you may have caused other issues if it's torn or leaking. You can unplug the TPS and the MC solenoid and the car will still run, although not very good so I doubt the TPS had anything to do with your original problem. What was the TPS voltage before you replaced it? That code could have been set by someone unplugging the connector with the car running. The voltage needs to be checked from closed throttle to wide open throttle, with the engine not running. It should read from .5v to about 5v without any opens through the full range, but a faulty TPS in a carbureted engine won't cause it to stall.
When I check the pressure of fuel I just hooked up to hard line I unscrewed from car and cranked car. There's no way to hook up on carb side. I did the TPS and replaced the gasket. I checked old TPS yesterday when messing with car and at idle was reading 1.18V.
 
When I check the pressure of fuel I just hooked up to hard line I unscrewed from car and cranked car. There's no way to hook up on carb side. I did the TPS and replaced the gasket. I checked old TPS yesterday when messing with car and at idle was reading 1.18V.
You need to disconnect the line from the carb and put a "T" in between the line and the fuel inlet. You can just use rubber hose, but you'll need to get a short 3/8 brake line and cut it and install one piece into the fuel inlet. Make sure to use hose clamps on the lines.1.18v is too high, but that won't cause your issue. Make sure that the throttle is fully closed when checking the voltage at idle. Make sure that it's not on the fast idle cam.
 
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Used a multimeter I was just checking to see how high it was. I just plugged it back in.
Yeah but it has to be set properly with the adjusting screw. Just plugging it in doesn’t do anything useful. Once you remove the tps from the carb volt readings are of no value.
 
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Its very common for E10 gas to damage accel pump cup seals, mainly low quality seals. Try manually depressing the plunger itself, it should immediately pop back up. If it doesn't then the cup seal has likely swollen.
 
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This problem is reminiscent of the older problem of s stuck heat riser valve .You know that exhaust checking plate GM installed on the exhaust manifold to cause hot exhaust fire to flow under carbs for first 6 minets. They would rust or get bent there by causeing to much heat in the manifold and boiling fuel to the point of stalling a motor at lower rmps.So it's been a while so much for looking back oh the cure for said situ. Sometimes a hammer and tapping would open a clogged riser valve.. other times disassembly and resizing the butterfly shaft with sandpaper or removal of damper plate ,and holes where removed shaft was were blocked with bolts held with nuts " of threaded ( no nuts lol" specifics of mechanism were that said riser opened automatically by gravity acting on a counter weight and a thermostatic spring yhat closed valve when manifold cooled (winter), Then they upgraded the gravity concept with a vacume servo..actuated by a vacuume switch coordinated to a Thermostatic vacuume switch in the water jacket with 3 feet of vacuume line,!...tell me if I'm wrong lol"
 
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Could be either an ignition module or other electronics failing or a fuel problem. Checked fuel filter? There are simple tests for both.
 

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