I have a 99 Z24 2.4l thats having really bad idle, hesitation, and misfire problems. In the process of trouble shooting, i noticed that after running the car for a while the intake manifold gets cold. Its wierd. The black plastic over the manifold actually accumulates condensation right below the throttle body. What could cause this? Does it have anything to do with that ugly miss?

i know pressure changes will also cause temperature differences,kinda like ur AC system, anyway... cracked intake? have u sprayed carb cleaner around the intake while its running to see if it makes a change in idle quality? hope this helps

i dont see any cracks on the manifold and i seafomed the throttle body and the gas tank to try to help things out, but got no where if not worse - after days of workin on the car i actually found some of the seafoam still sitting in the intake manifold right below the throttle body. I siphoned it out, but still nothing. it actually dies within SECONDS of idling now. I switched out idle air control, ignition coils, and spark plugs and they all made no difference. I think i should try testing the actual ignition housing, but um not sure how to.

okay! very interesting discovery: i found gas sitting in the bottom of the intake manifold! I siphoned it out and tried to start the engine and it will crank strong, but wont turn over. I checked the intake manifold by looking through the throttle body again and there is now MORE gas! i siphoned that out and now i see that every time i try to start the engine, it only cranks and pumps gas into the intake manifold. WHY IS THIS HAPPENING? i assuming maybe injectors? or timing not right?

side note: the car also has a very bad miss and it backfired through the throttle body: while trying to troubleshoot those problems, i found the gas.

ANY INPUT OR HELP IS APPRECIATED... thank you