87 Suburban boggs down, backfires once in awhile, and dies.

it appears you have electronic throttle control. any applicable trouble codes, relating to that system? clean the throttle bore and around throttle plate, don't force the throttle plate. your idle air is electronically controlled.

Vehicle information ?

change the coil wire . it sounds like it wasn't manufactured properly

What engine ? 4.3 , 4.8 , 5.3 or 6.0 l What fuel injection system ? What is the fuel pressure ? Do you know what fuel trims are ? The fuel pressure regulator's are prone to leaking to leaking on thses SPI injection system./
How to identify and repair leaking fuel pressure regulator GM CPI system...

Check the fuel pressure, could be the fuel pump

Timing chain may have slipped a link.

Have you checked the fuel pressure under a load, low pressure will cause these symptoms. The test port is on the top of the engine in the fuel supply rail to the fuel injectors, the fuel pressure test port looks like a large tire fill valve. You will need a fuel pressure test gauge to do this test (about $20), the pressure must be watched while you accelerate, it should never go down on hard acceleration just up about 6-8 PSI

It sounds like your ignition coil is overheating. Once it cools down it will fire properly until it gets hot again. Replace the ignition coil and you should be all set.

check for vacuum leaks at throttle body gasket. pvc valve stuck open.if all is good .change fuel filter .if still stall out check fuel pump pressure.if all is good .replace plugs and wires if they have not been changed.

sound like throttle position sensor.