1994 Sundance

I have a 1994 Plymouth Sundance 2.2l 4cyl and it has been sitting up for 1 year. Just replaced the fuel pump and started it up for the first time and it runs fine except for one thing, when I accelerate hard it tries to go dead, if I put it in neutral I can floor it with no problem and it idles good. I dont know what it is, any help would be great, thanks.

Well, for starters with a car that has sat that long, more should have been done before you started it. But it is running, and that is a big thing. You need to replace, or at least check, your spark plugs for corrosion and fouling, apply fresh dielectric grease to the plugs and wires where needed (check at the induction coil too). Change the air filter, the pcv breather filter, get an oil change (dont flush the system, as that is more likely to stir up bad sediments and deposit them where you dont want them then it is to get rid of them). Check the distributor cap for corrosion or cracks (could cause some hesitation in the engine under load). Check the condition and tension on all the belts. Check all the coolant hoses for splits and cracks and softness. Check transmission and brake fluid levels. All the good stuff. Get a Haynes manual for your car and go over the tune up section. The hesitation could be a few things, like a bad gasket in a TBI is throwing the vacuum off, or your O2 sensor is bad and the computer doesnt realise you are accelerating and the timing is off. Try going to an autoparts store like Autozone where they will scan the diagnostic port for free and help you focus in on it. I would say it is likely a sensor or fuel related problem. Good luck.