Help please. I have searched "hesitation" and looked at the FAQ for 7../9../90 cars. Nothing makes sense. Here's my symptoms:

89 245 starts right up every time. idles good. warm up one minute, put in reverse out of driveway, feels like it might stall as I first press gas, like it's not getting fuel. Put it in drive and it putts...stutters...sometimes stalls. I "feather" the gas a few times, and voila...it either clears up or stalls. If it clears up, it runs perfect from here. If it stalls, I start it up again and its runs fine from here on out.

As it drives this happens somewhat erratically as its warming up: from a standstill/stoplight, I will give it gas and there is a slight (putt-putt-gas....) then it goes along fine. After its driven for 15 minutes or so it will never do this.

I will stop the car to go into a store for 10 minutes, maybe half an hour or maybe for an hour or more, yet it still does this ritual at FIRST ACCELERATION, MOST of the time.

This erraticness is driving me nuts. Thoughts on where to start? Also, the fuel pump SEEMS to be working ok, but what are the specs for proper operation? I have an aftermarket pump I can't tell what it is (no markings, no stamp, no paint). The check valve has no "innards" in it. Just an open tube. It should have a mini valve inside should it not?

I get about 16-18 mpg right now mixed hwy/city, and this and the hesitation suck.