i have a 94 gt with the 5.0 and a 5-speed. when it is cold it runs fine but as soon as it warms up it starts missing and bucking. it only does this when i get to 2000 rpms. also when i cruize for a while in fith gear at 1500rpms and then get on the gas it drives fine for a while and then goes back to how it was. it started doing this a while back but it only did it every once n a while and then smoothed out. now it is doing it all the time. here is a list of what i have replaced. plugs gaped at .054 what the book said, wires, coil, cap, rotor, TPS, MAF, IAC, fule pump, fule filter, fule pressure regulator, set the timing, cleaned the egr. i have ran sea foam through the vacum line to clean it out, sprayed carb cleaner around the intake and vacum lines no change. i have ran just about every cleaner short of jet fule through the tank. i dont no what else to do and i am tired of wasting money on stuff thats not working. o and also when i rev it up the rpms take about 5 seconds to come back down and when i shift the rpms climb about 500rpms 1st-4th gear. about 1000rpms from 4th-5th

 

Vacuum leak

 

Do you no what vacum line cauz I checked most of them.

 

Vacuum leak can also mean intake gasket leak as well.

 

Ya I sprayed carb cleaner all around the intake and there was no change at all

 

90% of the time, spraying carb cleaner wont do a damn thing. Your car is 17 years old now... Replace any and all rubber hoses you can find under the hood. Also, start checking the hard plastic lines that are used, because they too will get brittle and break.

 

Ok will do ill post back and let you no what I find

 

ok so i got the missing and bucking problem fixed it was the egr valve. now i have a rattle comming from under the hood when i accelerate and the engine will run hot when i accelerate. i just replaced the water pump about 3 weeks ago. any ideas?

 

Noises that come and go with acceleration tend to be in the belt system. Given that you just did a water pump, and you have overheating problems, I'd say the pump has issues.

 

Ok the rattle was spark knock time out. The distributer came loose n moved. I replaced the vacuum lines n intake gaskets n still having some problems with missing. Would the coolent temp switch effect this at all because its still running great when its cold but I start having the trouble when it warms up. N thanks for the help n info so far.