fuel injection

Im trying to get my 89 GrandAm running right.It has a dead spot right of of idle.It wants to stall.Once I get past that spot it runs just fine.When I have it idling in the garage I step on it hard it backfires stalls a little and then runs fine.The engine is a guad 4 I replaced the throttle posisition senser with no luck.Does anybody have any ideas what could be wrong?
Thanks Brett

is the check engine lamp on? if it is unplug the tps and pull on the wires on the plug they were known for broken wires at the tps connector

The check engine light is not on and the wires seem to be fine.

Have you ever changed the fuel filter, sounds like a fuel delivery prob.

yes new filter new pump

come on guys give me some more ideas i give up.

does it idle smooth? if not they are known for bad coil housings you can try replacing it. that's if it has a misfire you'r next step would be to check the fuel pressure. it could be a faulty fuel pressure regulator.

It idles smooth just has a dead spot and backfire when you step on it then runs fine.

sounds like a lean misfire too much involved to diagnose over the net.recheck your fuel pressure when it acts up look at the gauge see if it's dropping too much could be a new defective pump.