I have a 93 gmc 2500 suburban with a 454. It started hesitating about 3 weeks ago under load conditions. I changed the fuel filter and nothing happened. It continually got worse. I pulled the air cleaner and inspected the injectors on the TBI. The drivers side was not spraying like the passenger side. I pulled the injector and inspected it, and it seems fine, but who knows. Put it all back together and now it leaks when I turn the key on. I wonder if the coil might have something to do with the hesitation....with the cleaner off, I really floored the engine and a fire started in the carb. It sounded more like a backfire than a hesitation when I was under the hood.