Hey Y'all, I am a new member however I have visited here many times. Any help I get here will be much appreciated.

My 95 suburban 4X4 with 350 TBI with 127K miles about one out of ten hot starts is a bear. I know it's not an "F Body” but you guys know more bout TBI than other folks.

Approximately one out of ten times when I try to start my suburban when it is hot it will only start when I apply WOT.
The friendly GM service man said that WOT on a hot start was a "flood clear mode". With closed throttle or partial open the engines just turns oven with no indication of starting. The other nine times or when it’s cold it always starts and behaves as it should. The problem is becoming more frequent.

When it does start it will black smoke and run roughly for 20 seconds and I must keep the RPSs high or else it will stall.
Then once it decides to run it runs and drives as normal with no hesitation or black smoke. At Idle you can smell a rich fuel mixture from the exhaust but no black smoke.

About two months ago I replaced the intake manifold gasket because of an external coolant leak. At that time I replaced plugs, wires, cap, rotor, 3 wire O2 sensor (like out of a 94 PU) belts & hoses. I have replaced the EGR valve. About two years ago while on a trip I got a code indication for the TPS. After shutting down and checking the TPS with a volt meter the check engine light went away. No other codes or parts replaced on my suburban.

I have checked for a vacuum leak by spraying WD 40 around the intake manifold to cylinder to head and intake manifold to TBI surfaces. No indication of leakage. One time after a hard start it did give a service engine light however it went away within a minute or two.

Does this sound like an injector problem?

I love my suburban mainly because it is paid for however I will replace it after I get two of my sons out of college. That may take a long time…

Thanks In Advance

10yearoldchevy