93 chevy suburban v-8 tbi hard to start, but starts, will run but will not idle, can keep it running or driving as long as you rev engine constantly. Holding engine at half throttle it will slow and die. you can see gas spray from both tbi injectors but cannot tell if amount gets less when engine dies from fast steady throttle. Last code lean O2.

possible loose, bad or broken electrical contact that is cutting off current to vital part of the engine.

didnt specify year model or engine --generic answer --if the tbi is flooding ---check the fuel pressure regulator --and the tbi itself

SKM, fuel pressure regulator is on top of throttle body. This could be the problem, could also be vacuum leak, faulty EGR, etc. You may want a good Tech, to diagnose and estimate repair. Check the attached links,instruction and guides, Good luck
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TBI 220 Fuel pressure regulator change 1
92 chevy truck missing at constant speeds The 1947 Present Chevrolet GMC...
Where is the fuel pressure regulator on 1994 Chevy truck 5 7 TBI fuel...
started stalling and dying when in gear

Have you checked to be sure the idle air control is working properly and also the engine temp control sw. The iac only comes on to maintain the idle when the engine is cold. The ect sw monitors the outside temp and tells the computer how much fuel to put to the engine. Hope this helps.

Lets start at the beginning. Is the check engine light on ?
You have an idle air control valve which could be sticking open or shorted to ground. You should be able to unplug it to test. There also could be a gasket or hose that is opening up and causing a huge vac leak.

Sounds like the fuel pump is going bad(or in this case,has gone bad). I suggest that you change the fuel pump and use a fuel cleaner in your gas tank as dirty gas may have caused the problem to begin with.

Check brake system. Resurface brake rotors. Replace pads. Check drums and shoes. Fush system. I use cross drilled rotors and carbon fiber pads. Stop in a hurry. Some Suburbans (94 and up) have slow ABS units that take their time to allow brakes to activate.

What age? What Mileage?

Brake hoses go bad and either prevent brakes from operating or prevent them from pulling back after being applied. Had this problem too.

Also check for vaccuum leaks. TBI engines had a loose metal tube under the TBI unit. I had a vaccuum leak and had to tighten my tube 6 times @ 1/4 turn each. Solved problem.

Try to use some liquid around vaccuum hoses and see if idle changes. Non TBI engines have plastic intake issues.

Check check valve in vaccuum booster. My was bad too.

Molded hose neeed to be replaced. I used two hoses and a brake booster filter in the HELP section to make the 90 degree turn from the hard line to the check valve.

93 Suburban 2WD. Runs great now. 16 mpg city.

GM's have a bad issue with fuel pumps failing. If you do not have a pressure tester have someone spray a little quick start when its barely running, If it idles better ,,then the fuel pump will need to be tested.

Its also possible the problem is the idle air control valve. If you can get it running and it will rev up and drive ok off idle and idle is the only issue then most liklely the IAC is faulty.

The fuel pump should be in the 20s. Also it could be losing presure slowly. Leave the fuel pump pressure gage on for at least 2 to 3 hours to see if it is losing pressure - It's a start

sounds like a computer issue on the burb, but i would check the IAC(idle air control) valve and the TPS(throttle position sensor) first.
I would start with the IAC on the 93'.