Chevrolet Repair: possible fuel problem, throttle position sensor, electric fuel pump

Question
Hi. I have a 1994 chevy 1,ton crew cab p/u, with 350, throttle body injection. The other day I noticed it was hesitating on take off, If I gave it to much gas it seemed to bog down like it was going to die, but if I let off the gas and eased into it then it would run alright. I put a new fuel filter on it and a bottle of heet in the gas tank and that did not seem to fix the problem, today I put a new distributer cap and rotor on it and it is still not running right. Can the electric fuel pump be going out slowley or would it just stop working. What else can I check ?  

Answer
Hi Cody,
Usually the pump works, or it doesn't.
A pressure tester connected would be the best idea.
Let me tell you two different problems that can make that happen.
For the cheapest, you will need the pressure tester. I had one doing that, and checked the obvious stuff, then stuck a pressure guage on it.
7PSI....not good. Should be 14.
Pump sounded good...so I dropped the tank, and was about to send for a pump, when I noticed a little bulge in the hose that connects the pump to the tank assembly.
Being somewhat curious, I filled a bucket with DIESEL fuel, (don't like to mess with electric connections and an open bucket of gasoline). Connected the pump to power, and it pumped like crazy. Stuck the guage on the end of the line, and the pressure was 7PSI, and diesel spraying out through a split in the bulge.
Stuck a piece of fuel line hose on there,(only about an inch and a half long), and 15 PSI. That beast is still running great, on the same pump.

Possibility 2...there is a throttle position sensor on the throttle body. You actually physically open the throttle plate, but the sensor tells the ecm what you want, and it pumps in more fuel to go with that slug of air you just let in. If the sensor isn't working, you have a very lean mixture.
The engine will actually run without that sensor. The ecm just uses a default average, and puts some fuel in. Too much for idle, and not enough for a heavy load, or fast acceleration, but enough to run fairly.
That sensor can be tested with an ohm meter.
A loose wire connection to it can also cause the problem.

One of those may well fix you up.
Good luck,
Van