92 1500 hesitates

I have a 92 c1500 2wd with a 4.3 V6 with 150,000 miles on it. The engine runs fine when cold during idling and driving. When it gets up to temp, it hesitates and 'bucks' but does not stall. The problem is worse when you get into the gas pretty hard from a dead stop or from a slow speed. It is also noticable during highway speeds. So far I have done a tune up, changed fuel filter and O2 sensor. I used some Lucas fuel treatment with no luck either. During this hesitation I am not seeing any check engine lights come on at all. A friend told me it could be the egr valve or the egr vaccuum solenoid. Any help would be appreciated.

I'm sorry for two reasons. 1. I don't know what your problem is I cant help. 2. You have a 4.3L :D

fuel pump flow or fuel pressure regulator in the TBI unit

That or fuel filter.

A fresh set of plug wires solved the problem. The wires did not look bad at all, but there was a bad one somewhere. Thanks to those who replied. broughy84 sorry you are a 4.3L hater. I like that motor. Enough power for anything I need to get done.

nothing against you or your truck, they are good motors (for an Astro van), but all kidding aside, they are a good motor, I just like my SBC 350 TBI a little better.