ok i start my car and it idles around 1200 while its warming up fuel pressure is about 32psi, than about 5 minutes into the warmup the fuel pressure gradually increases up to 38psi. while the fuel pressure goes up the idle is very lumpy and the engine starts bucking, this continues for about 2-3 minutes than the cars idles and runs perfect (fuel pressure goes back down to 32). if i hit the gas while the idle is lumpy the fuel pressure goes up to about 40 than down to 32 and run normal for about 10 seconds than it begins the upward climb and becomes lumpy and jumpy again. the car is a 2000 ex and the engine is currently stock. what could be the problem?

 

clogged fuel filter, weak fuel pump or defective fuel press. regulator. clean throttle plate while your in there. good luck